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Sunday, February 6, 2022

Mental disorders and gender

From Wikipedia, the free encyclopedia

Gender is correlated with the prevalence of certain mental disorders, including depression, anxiety and somatic complaints. For example, women are more likely to be diagnosed with major depression, while men are more likely to be diagnosed with substance abuse and antisocial personality disorder. There are no marked gender differences in the diagnosis rates of disorders like schizophrenia, borderline personality disorder, and bipolar disorder. Men are at risk to suffer from post-traumatic stress disorder (PTSD) due to past violent experiences such as accidents, wars and witnessing death, and women are diagnosed with PTSD at higher rates due to experiences with sexual assault, rape and child sexual abuse. Nonbinary or genderqueer identification describes people who do not identify as either male or female. People who identify as nonbinary or gender queer show increased risk for depression, anxiety and post-traumatic stress disorder. People who identify as transgender demonstrate increased risk for depression, anxiety, and post-traumatic stress disorder.

Sigmund Freud postulated that women were more prone to neurosis because they experienced aggression towards the self, which stemmed from developmental issues. Freud's postulation is countered by the idea that societal factors, such as gender roles, may play a major role in the development of mental illness. When considering gender and mental illness, one must look to both biology and social/cultural factors to explain areas in which men and women are more likely to develop different mental illnesses. A patriarchal society, gender roles, personal identity, social media, and exposure to other mental health risk factors have adverse effects on the psychological perceptions of both men and women.

Gender differences in mental health

Gender-specific risk factors

Gender-specific risk factors increase the likelihood of getting a particular mental disorder based on one's gender. Some gender-specific risk factors that disproportionately affect women are income inequality, low social ranking, unrelenting child care, gender-based violence, and socioeconomic disadvantages.

Anxiety

Women experience a higher rate of General Anxiety Disorder (GAD) than men. Women are around 15% more likely to experience comorbidities with GAD than men. Anxiety disorders in women are more likely to be comorbid with other anxiety disorders, bulimia, or depression. Women are two and a half times more likely to experience Panic Disorder (PD) than men. Women are also twice as likely to develop specific phobias. Additionally, Social Anxiety Disorder (SAD) occurs among women more frequently than men. Obsessive-compulsive Disorder (OCD) is present among women and men at similar rates, though women tend to have a later onset of symptoms. With OCD, men are more likely to experience more aggressive, sexual-religious, and social impairments while women are more likely to experience fear of contamination.

Gender is not a significant factor in predicting the effectiveness of pharmacological interventions or cognitive behavioral therapy in treating GAD.

Depression

Major depressive disorder is twice as common in women compared to men. This increased rate is partially related to women's increased likelihood to experience sexual violence, poverty, and higher workloads. Depression in women is more likely to be comorbid with anxiety disorders, substance abuse disorders, and eating disorders. Men are less likely to seek treatment for or discuss their experiences with depression. Men are more likely to have depressive symptoms relating to aggression than women. Women are more likely to attempt suicide than men however, more men die from suicide due to the different methods used. In 2019, the suicide rate in the United States was 3.7 times higher for men than women.

The presence of a gender bias results in an increased diagnosis of depression in women than men.

Postpartum depression

Men and women experience postpartum depression. Maternal postpartum depression affects around 15% of women in the United States. Postpartum depression is under-diagnosed. Women experiencing PPD have trouble seeking treatment due to the difficulties of accessing therapy and not being able to take some psychiatric medications due to breastfeeding. Around 8-10% of American fathers experience paternal postpartum depression (PPPD). Risk factors for PPPD include a history of depression, poverty, and hormonal changes.

Eating disorders

Women constitute 85-95% of people with anorexia nervosa and bulimia and 65% of those with a binge-eating disorder. Factors that contribute to the gender disproportionality of eating disorders are perceptions surrounding "thinness" in relation to success and sexual attractiveness and social pressures from mass media that are largely targeted towards women. Between males and females, the symptoms experienced by those with eating disorders are very similar such as a distorted body image.

Contrary to the stereotype of eating disorders' association with females, men also experience eating disorders. However, gender bias, stigma, and shame lead men to be underreported, underdiagnosed, and undertreated for eating disorders. It has been found that clinicians are not well-trained and lack sufficient resources to treat men with eating disorders. Men with eating disorders are likely to experience muscle dysmorphia.

Gender differences in adolescence and mental health

Adolescents experience mental illness differently than an adult, as children's brains are still developing and will continue to develop until around the age of twenty-five. Children also approach goals differently, which in turn can cause different reactions to stressors such as bullying.

Bullying

Studies have shown that adolescent males are more likely to be bullied than females. They have also posed that status enhancement is one of the main drives of bullying and a 1984 study by Kaj Björkqvist et al. showed that the motivation of male bullies between the ages of 14-16 was the status goal of establishing themselves as more dominant. A bully's gender and the gender of their target can impact whether they are accepted or rejected by a gender group, as a 2010 study by René Veenstra et al. reported that bullies were more likely to be rejected by peer groups who saw them as a possible threat. The study cited an example of a male elementary school bully who was rejected by their female peers for targeting a female student while a male bully who only targeted other males were accepted by females but rejected by their male peers.

Eating disorders

The fashion industry and media have been cited as potential factors in the development of eating disorders in adolescents and pre-adolescents. Eating disorders have been found to be most common in developed countries and per scholars such as Anne Becker, the introduction of television has prompted an increase of eating disorders in media-naïve populations. Females are more likely to have an eating disorder than males and scholars have stated that this has become more common "during the latter half of the twentieth century, during a period when icons of American beauty (Miss America contestants and Playboy centerfolds) have become thinner and women’s magazines have published significantly more articles on methods for weight loss". Other potential reasons for eating disorders among adolescents and pre-adolescents can include anxiety, food avoidance emotional disorder, food refusal, selective eating, pervasive refusal, or appetite loss as a result of depression.

Suicide

Data has shown that suicide is the third leading cause of death in adolescents and that gender has an impact on the avenue an adolescent may use when attempting suicide. Males are known more to use guns in their suicide attempts, whereas females are more likely to cut their wrists or take an overdose of pills. Triggers for suicide among adolescents can include poor grades and relationship issues with significant others or family members. Research has reported that while adolescents share common risk factors such as interpersonal violence, existing mental disorders and substance abuse, gender specific risk factors for suicide attempts can include eating disorders, dating violence, and interpersonal problems for females and disruptive behavior/conduct problems, homelessness, and access to means. They also reported that females are more likely to attempt suicide than their male counterparts, whereas males are more likely to succeed in their attempts.

Effects of Social Media on Body Image

During early adolescence, one's perception of physical appearance becomes increasingly important, having a significant impact on one's self-worth. Studies have shown that social media use among adolescents is associated with poor body image. This is due to the fact that social media use increases body surveillance. This means that adolescents regularly compare themselves to the idealized bodies they see on social media causing them to develop self-deprecating attitudes. Both adolescent boys and girls are impacted by the objectifying nature of social media, however young girls are more likely to body surveil due to society's tendency to overvalue and objectify women. A study published in the Journal of Early Adolescence found that there is a significantly stronger correlation between self-objectified social media use, body surveillance, and body shame among young girls than young boys. The same studied emphasized that adolescence is an important psychological development period; therefore, opinions formed about oneself during this time can have a significant impact on self-confidence and self-worth. Consequently, low self-esteem can increase one's risk of developing an eating disorder, depression, and/or anxiety.

Gender differences following a traumatic event

Post-traumatic stress disorder (PTSD)

Post-traumatic stress disorder (PTSD) is among the most common reactions in response to a traumatic event. Research has found that women have higher rates of PTSD compared to men. According to epidemiological studies, women are two to three times more likely to develop PTSD than men. The lifetime prevalence of PTSD is about 10-12% in women and 5-6% in men. Women are also four times more likely to develop chronic PTSD compared to men. There are observed differences in the types of symptoms experienced by men and women. Women are more likely to experience specific sub-clusters of symptoms, such as re-experiencing symptoms (e.g. flashbacks), hypervigilance, feeling depressed and numbness. These differences are found to be persistent across cultures. A significant risk factor or trigger of PTSD is rape. In the United States, 65% of men and 45.9% of women who are raped develop PTSD.

Epidemiological studies have found that men are more likely to have PTSD as a result of experiencing combat, war, accidents, nonsexual assaults, natural disaster, and witnessing death or injury. Meanwhile, women are more likely to have PTSD attributed to rape, sexual assault, sexual molestation, and childhood sexual abuse. However, despite the theorized explanation that gender differences were due to different rates of exposure to high impact traumas such as sexual assaults, a meta-analysis found that when excluding instances of sexual assault or abuse, women remained at a greater risk for developing PTSD. Additionally, it has been found that when looking at those who have only experienced sexual assaults, women remained approximately twice as likely as men to develop PTSD.[41] Thus, it is likely that exposure to specific traumatic events such as sexual assault only partially accounts for the observed gender differences in PTSD.

Depression

While PTSD is perhaps the most well-known psychological response to a trauma, depression can also develop following exposure to traumatic events. Under the definition of sexual assault as pressured or forced into unwanted sexual contact, women encounter two times the rate of sexual assault as men. A history of sexual assault is related to increased rates of depression. For example, studies of survivors of childhood sexual assault found that the rates of childhood sexual assault ranged from 7-19% for women and 3-7% for men. This gender discrepancy in childhood sexual assault contributes to 35% of the gender difference in adult depression. Increased likelihood of adverse traumatic experiences in childhood also explains the observed gender difference in major depression. Studies show that women have an increased risk of experiencing traumatic events in childhood, especially childhood sexual abuse. This risk has been associated with an increased risk of developing depression.

As with PTSD, evidence of a biological difference between men and women may contribute to the observed gender difference. However, research on the biological differences of men and women who have experienced traumatic events is yet to be conclusive.

Gender differences in mental health within the LGBTQ+ community

Risk factors and the minority stress model

The minority stress model takes into account significant stressors that distinctly affect the mental health of those who identify as lesbian, gay, bisexual, transgender, or another non-conforming gender identity.[48] Some risk factors that contribute to declining mental health are heteronormativity, discrimination, harassment, rejection (e.g., family rejection and social exclusion), stigma, prejudice, denial of civil and human rights, lack of access to mental health resources, lack of access to gender-affirming spaces (e.g., gender-appropriate facilities), and internalized homophobia. The structural circumstance where a non-heterosexual or gender non-conforming individual is embedded in significantly affects the potential sources of risk. The compounding of these everyday stressors increase poor mental health outcomes among individuals in the LGBTQ+ community. Evidence shows that there is a direct association between LGBTQ+ individuals' development of severe mental illnesses and the exposure to discrimination.

In addition, there are a lack of access to mental health resources specific to LGBTQ+ individuals and a lack of awareness about mental health conditions within the LGBTQ+ community that restricts patients from seeking help.

Limited research

There is limited research on mental health in the LGBTQ+ community. Several factors affect the lack of research on mental illness within non-heterosexual and non-conforming gender identities. Some factors identified: the history of psychiatry with conflating sexual and gender identities with psychiatric symptomatology; medical community's history of labelling gender identities such as homosexuality as an illness (now removed from the DSM); the presence of gender dysphoria in the DSM-V; prejudice and rejection from physicians and healthcare providers; LGBTQ+ underrepresentation in research populations; physicians' reluctance to ask patients about their gender; and the presence of laws against the LGBTQ+ community in many countries. General patterns such as the prevalence of minority stress have been broadly studied.

There is also a lack of empirical research on racial and ethnic differences in mental health status among the LGBTQ+ community and the intersection of multiple minority identities.

Stigmatization of LGBTQ+ individuals with severe mental illnesses

There is a significantly greater stigmatization of LGBTQ+ individuals with more severe conditions. The presence of the stigma affects individuals' access to treatment and is particularly present for non-heterosexual and gender non-conforming individuals with schizophrenia.

Anxiety

LGBTQ+ individuals are nearly three times more likely to experience anxiety compared to heterosexual individuals. Gay and bisexual men are more likely to have generalized anxiety disorder (GAD) as compared to heterosexual men.

Depression

Individuals who identify as non-heterosexual or gender non-conforming are more likely to experience depressive episodes and suicide attempts than those who identity as heterosexual. Based solely on their gender identity and sexual orientation, LGBTQ+ individuals face stigma, societal bias, and rejection that increase the likelihood of depression. Gay and bisexual men are more likely to have major depression and bipolar disorder than heterosexual men.

Transgender youth are nearly four times more likely to experience depression, as compared to their non-transgender peers. Compared to LGBTQ+ youth with highly accepting families, LGBTQ+ youth with less accepting families are more than three times likely to consider and attempt suicide. As compared to individuals with a level of certainty in their gender identity and sexuality (such as LGB-identified and heterosexual students), youth who are questioning their sexuality report higher levels of depression and worse psychological responses to bullying and victimization.

31% of LGBTQ+ older adults report depressive symptoms. LGBTQ+ older adults experience LGBTQ+ stigma and ageism that increase their likeliness to experience depression.

Post-traumatic stress disorder

LGBTQ+ individuals experience higher rates of trauma than the general population, the most common of which include intimate partner violence, sexual assault and hate violence. Compared to heterosexual populations, LGBTQ+ individuals are at 1.6 to 3.9 times greater risk of probable PTSD. One-third of PTSD disparities by sexual orientation are due to disparities in child abuse victimization.

Suicide

As compared to heterosexual men, gay and bisexual men are at a greater risk for suicide, attempting suicide, and dying of suicide. In the United States, 29% (almost one-third) of LGB youth have attempted suicide at least once. Compared to heterosexual youth, LGB+ youth are twice as likely to feel suicidal and over four times as likely to attempt suicide. Transgender individuals are at the greatest risk of suicide attempts. One-third of transgender individuals (both in youth and adulthood) has seriously considered suicide and one-fifth of transgender youth has attempted suicide.

LGBT+ youth are four times more likely to attempt suicide than heterosexual youth. Youth who are questioning their gender identity and/or sexuality are two times more likely to attempt suicide than heterosexual youth. Bisexual youth have higher percentages of suicidality than lesbian and gay youth. As compared to white transgender individuals, transgender individuals who are African American/black, Hispanic/Latinx, American Indian/Alaska Native, or Multiracial are at a greater risk of suicide attempts. 39% of LGBTQ+ older adults have considered suicide.

Substance abuse

In the United States, an estimate of 20-30% of LGBTQ+ individuals abuse substances. This is higher than the 9% of the U.S. population that abuse substances. In addition, 25% of LGBTQ+ individuals abuse alcohol compared to the 5-10% of the general population. Lesbian and bisexual youth have a higher percentage of substance use problems as compared to sexual minority males and heterosexual females. However, as young sexual minority males mature into early adulthood, their rate of substance use increases. Lesbian and bisexual women are twice as likely to engage in heavy alcohol drinking as compared to heterosexual women. Gay and bisexual men are less likely to engage in heavy alcohol drinking as compared to heterosexual men.

Substance use such as alcohol and drug use among LGBTQ+ individuals can be a coping mechanism in response to everyday stressors like violence, discrimination, and homophobia. Substance use can threaten LGBTQ+ individuals' financial stability, employment, and relationships.

Eating disorders

The average age for developing an eating disorder is 19 years old for LGBTQ+ individuals, compared to 12–13 years old nationally. In a national survey of LGBTQ youth conducted by the National Eating Disorders Association, The Trevor Project and the Reasons Eating Disorder Center in 2018, 54% of participants indicated that they had been diagnosed with an eating disorder. An additional 21% of surveyed participants suspected that they had an eating disorder.

Various risk factors may increase the likelihood of LGBTQ+ individuals experiencing disordered eating, including fear of rejection, internalized negativity, post-traumatic stress disorder (PTSD) or pressure to conform with body image ideals within the LGBTQ+ community.

42% of men who experience disordered eating identify as gay. Gay men are also seven times more likely to report binge eating and twelve times more likely to report purging than heterosexual men. Gay and bisexual men also experience a higher prevalence of full-syndrome bulimia and all subclinical eating disorders than their heterosexual counterparts.

Research has found lesbian women to have higher rates of weight-based self-worth and proneness to contracting eating disorders compared to gay men. Lesbian women also experience comparable rates of eating disorders compared to heterosexual women, with similar rates of dieting, binge eating and purging behaviours. However, lesbian women are more likely to report positive body image compared to heterosexual females (42.1% vs 20.5%).

Transgender individuals are significantly more likely than any other LGBTQ+ demographic to report an eating disorder diagnosis or compensatory behaviour related to eating. Transgender individuals may use weight restriction to suppress secondary sex characteristics or to suppress or stress gendered features.

There is limited research regarding racial differences within LGBTQ+ populations as it relates to disordered eating. Conflicting studies have struggled to ascertain whether LGBTQ+ people of colour experience similar or varying rates of eating disorder proneness or diagnosis.

Causes of gender disparities in mental disorders

Intimate partner violence

Intimate partner violence (IPV) is a particularly gendered issue. Data collected from the National Violence Against Women Survey (NVAWS) of women and men aged 18–65 found that women were significantly more likely than men to experience physical and sexual IPV. According to The National Domestic Violence Hotline, "From 1994 to 2010, about 4 in 5 victims of intimate partner violence were female." The United Nations estimates that "35 percent of women worldwide have experienced either physical and/or sexual intimate partner violence or sexual violence by a non-partner (not including sexual harassment) at some point in their lives."

There have been numerous studies conducted linking the experience of being a survivor of domestic violence to a number of mental health issues, including post-traumatic stress disorder, anxiety, depression, substance dependence, and suicidal attempts. Humphreys and Thiara (2003) assert that the body of existing research evidence shows a direct link between the experience of IPV and higher rates of self-harm, depression, and trauma symptoms. The NVAWS survey found that physical IPV was associated with an increased risk of depressive symptoms, substance dependence problems, and chronic mental illness.

A study conducted in 1995 of 171 women reporting a history of domestic violence and 175 reporting no history of domestic violence confirmed these hypotheses. The study found that the women with a history of domestic violence were 11.4 times more likely to suffer dissociation, 4.7 times more likely to suffer anxiety, 3 times as likely to suffer from depression, and 2.3 times more likely to have a substance abuse problem. The same study noted that several of the women interviewed stated that they only began having mental health issues when they began to experience violence in their intimate relationships.

Another study found that in a group of women in a psychiatric inpatient hospital ward, women who were survivors of domestic violence were twice as likely to suffer depression as those were not. All twenty of the women interviewed fit into a pattern of symptoms associated with trauma-based mental health disorders. Six of the women had attempted suicide. Moreover, the women spoke openly of a direct connection between the IPV they suffered and their resulting mental disorders.

In a similar study, 191 women who reported at least one event of IPV in their lifetime were tested for PTSD. 33% of the women tested positively were lifetime PTSD, and 11.4% tested positive for current PTSD.

As far as males are concerned, it is estimated that 1 in 9 men experience severe IPV. For men as well, domestic violence is correlated with a higher risk of depression and suicidal behavior.

Sexual violence

Global estimates published by the World Health Organization indicate that about 1 in 3 (35%) of women worldwide have experienced either physical and/or sexual intimate partner violence or non-partner sexual violence in their lifetime.

Sexual violence increasingly impact adolescent girls who are subjected to forced sex, rape and sexual assault. Approximately 15 million adolescent girls (aged 15 to 19) worldwide have experienced forced sex (forced sexual intercourse or other sexual acts) at some point in their life.

Sexual assault, rape and sexual abuse are likely to impact a women's mental health on a short and long-term basis. Many survivors are "mentally marked by this trauma and report flashbacks of their assault, and feelings of shame, isolation, shock, confusion, and guilt." Additionally, victims of rape or sexual assault are at a higher risk for developing PTSD, with the lifetime prevalence being 50% compared to the average prevalence of 7.8%. Sexual assault is also associated with higher rates of depression, self harm, suicide, and disordered eating.

Social Media Pressures and Criticism

Social media is highly prevalent and influential among the current generation of adolescents and young adults. Approximately 90% of young adults in the United States have and use a social media platform on a regular basis. In terms of social media use and body image, boys experience social media as a higher positive influence on their body image than girls, who report social media causing more negative effects on their body image. Indeed, social media use has a connection to increased risk for eating disorders in women. Women receive greater amounts of pressure and criticism surrounding their physical appearance, making them more likely to internalize the body ideals that are glorified on social media.

Furthermore, Pro-anorexia communities are widespread among social media platforms which creates an environment that encourages disordered eating behaviors, and uses primarily photos of young women to spread unhealthy messages promoting thinness. Women are more likely to be involved with pro-anorexia communities.

Gender bias in medicine

The World Health Organization notes gender differentials in both the diagnosis and treatment of mental illness. Gender bias observed in diagnostic and healthcare systems (including as related to under-diagnosis, over-diagnosis, and misdiagnosis) is detrimental to the treatment and health of people of all genders.

The difference in diagnosis emerges at an early age, with diagnostic rates for children diverging on the basis of gender once children reach school age. These gendered differentials have been attributed to a variety of factors, including gendered socialization to internalize or externalize symptoms of distress, particularly in youth; clinician bias to perceive men as mentally healthy; gendered stereotypes regarding the types of disorders men and women are expected to experience, with emotional issues attributed to women and substance abuse issues to men; and stereotypes and allocation of resources based on, and reifying, these differences. Differential diagnosis rates are also related to differences in help-seeking or disclosure along gendered lines.

Diagnostic processes may be influenced by knowledge of a patient's sex or gender alone, and male and female patients may receive different diagnoses even when presenting the same symptoms. For instance, even with the same symptomology or scores according to diagnostic criteria, women are more likely to be diagnosed with depression than men.

Misogynistic Bias in Medicine

Misogynistic bias has impacted diagnosis and treatment of men and women alike throughout the history of psychiatry, and those disparities persist today.

Hysteria is one example of a medical diagnosis which bears a long history as a "feminine" disorder, whether associated with biological features or with "feminine" psychology or personality. For hundred of years in Western Europe, hysteria was seen as an excess of emotion and a lack of self-control, that would mostly impact women. The diagnosis was used as a form of social labeling to discourage women from venturing outside of their role, that is a tool to take control over the increasing emancipation of women.

Another instance in which such disparities emerged is in the use of lobotomies, popularized in the 1940s to treat a variety of psychiatric diagnoses including insomnia, nervousness, and more. Studies have found that US asylums disproportionately lobotomized women in spite of the fact that men made up the majority of asylum patients.

Cisheteronormative Bias in Medicine

Implicit bias in medicine also affect the way lesbian, gay, bisexual, transgender (LGBTQ+) patients, are diagnosed by mental health physicians. Due to internalized societal and medical bias, physicians are more likely to diagnosed LGBTQ+ patients with anxiety, depression and suicidality.

Gender Normativity and Bias in Medicine

It has also been observed that mental health professionals may pathologize the behaviors of individuals who do not conform to the practitioner's gender ideals. Gender ideals have been found to influence understandings of mental health and illness at the stages of diagnosis, treatment, and evaluation of symptomology or of treatment.

Socioeconomic status (SES)

Socioeconomic Status is a global term which refers to a person's income level, education and position in society. Most social science research agrees upon the fact that there is a negative relationship between socioeconomic status and mental illness, that is lower socio-economic status is correlated with higher level of mental illness. "Researchers have found this relationship to hold constant for almost any mental illness, from rare conditions like schizophrenia to more common mental illnesses like depression."

Gender disparities in socioeconomic status (SES)

SES is a key factor in determining one's opportunities and quality of life. Inequities in wealth and quality of life for women are known to exist both locally and globally. According to a 2015 survey of the U.S Census Bureau, in the United States, women's poverty rates are higher than men's. Indeed, "more than 1 in 7 women (nearly 18.4 million) lived in poverty in 2014."

US Gender Pay Gap by state in 2006

When it comes to income and earning ability in the United States, women are once again at an economic disadvantage. Indeed, for a same level of education and an equivalent field of occupation, men earn a higher wage than women. Though the pay-gap has narrowed over time, according U.S Census Bureau Survey, it was still 21% in 2014. Additionally, pregnancy negatively affects professional and educational opportunities for women since "an unplanned pregnancies can prevent women from finishing their education or sustaining employment (Cawthorne, 2008)".

The impact of gender disparities in SES on women's mental health

Increasing evidence tend to show a positive correlation between lower SES and negative mental health outcomes for women. Firstly, "Pregnant women with low SES report significantly more depressive symptoms, which suggests that the third trimester may be more stressful for low-income women (Goyal et al., 2010)." Accordingly, postpartum depression has proven to be more prevalent among lower-income mothers. (Goyal et al., 2010).

Secondly, women are often the primary care-taker for their families. As a result, women with insecure job and housing experience higher stress and anxiety since their precarious economic situation places them and their children at higher risk of poverty and violent victimization (World Health Organization, 2013).

Finally, a low socioeconomic status puts women at higher risk of domestic and sexual violence, therefore increasing their exposure to all the mental disorder associated with this trauma. Indeed, "statistics show that poverty increases people's vulnerabilities to sexual exploitation in the workplace, schools, and in prostitution, sex trafficking, and the drug trade and that people with the lowest socioeconomic status are at greater risk for violence" (Jewkes, Sen, Garcia-Moreno, 2002).

Biological differences

Research have been made on the effect of biological differences between male and female on the exposure to both Post-Traumatic Stress Disorder (PTSD) and Depression.

Post-traumatic stress disorder

Biological differences is a proposed mechanism contributing to observed gender differences in PTSD. Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been proposed for both men and women. The HPA helps to regulate an individual's stress response by changing the amount of stress hormones released into the body, such as cortisol. However, a meta-analysis found that women have greater dysregulation than men; women have been found to have lower circulating cortisol concentrations compared to healthy controls, where men did not have this difference in cortisol. It is also thought that gender differences in threat appraisal might contribute to observed gender differences in PTSD as well by contributing to HPA dysregulation. Women are reported to be more likely to appraise events as stressful and to report higher perceived distress in response to traumatic events compared to men, potentially leading to an increased dysregulation of the HPA in women than in men. Recent research demonstrates a potential link between female hormones and the acquisition and extinction of fear responses. Studies suggest that higher levels of progesterone in women are associated with increased glucocorticoid availability, which may enhance consolidation and recall of distressful visual memories and intrusive thoughts. One important challenge for future researchers is navigating fluctuations hormones throughout the menstrual cycle to further isolate the unique effects of estradiol and progesterone on PTSD.

Depression

Expanding on the research concerning the HPA and PTSD, one existing hypothesis is that women are more likely than men to have a dysregulated HPA in response to a traumatic event, like in PTSD. This dysregulation may occur as a result of the increased likelihood of women experiencing a traumatic event, as traumatic events have been known to contribute to HPA dysregulation. Differences in stress hormone levels can influence moods due to the negative effect of high cortisol concentrations on biochemicals that regular mood such as serotonin. Research has found that people with MDD have elevated cortisol levels in response to stress and that low serotonin levels are related to the development of depression. Thus, it is possible that a dysregulation in the HPA, when combined with the increased history of traumatic events, may contribute to the gender differences seen in depression.

Coping mechanisms in PTSD

For PTSD, genders differences in coping mechanisms has been proposed as a potential explanation for observed gender differences in PTSD prevalence rates. Tough PTSD is a common diagnosis associated with abuse and trauma for men and women, the "most common mental health problem for women who are trauma survivors is depression". Studies have found that women tend to respond differently to stressful situations than men. For example, men are more likely than women to react using the fight-or-flight response. Additionally, men are more likely to use problem-focused coping, which is known to decrease the risk of developing PTSD when a stressor is perceived to be within an individual's control. Women, meanwhile, are thought to use emotion-focused, defensive, and palliative coping strategies. As well, women are more likely to engage in strategies such as wishful thinking, mental disengagement, and the suppression of traumatic memories. These coping strategies have been found in research to correlate with an increased likelihood of developing PTSD. Women are more likely to blame themselves following a traumatic event than men, which has been found to increase an individual's risk of PTSD. In addition, women have been found to be more sensitive to a loss of social support following a traumatic event than men. A variety of differences in coping mechanisms and use of coping mechanisms may likely play a role in observed gender differences in PTSD.

These described differences in coping mechanisms are in line with a preliminary model of sex-specific pathways to PTSD. The model, proposed by Christiansen and Elklit, suggests that there are sex differences in the physiological stress response. In this model, variables such as dissociation, social support, and use of emotion-focused coping may be involved in the development and maintenance of PTSD in women, whereas physiological arousal, anxiety, avoidant coping, and use of problem-focused coping may be more likely to be related to the development and maintenance of PTSD in men. However, this model is only preliminary and further research is needed.

For more about gender differences in coping mechanisms, see the Coping (psychology) page.

Coping mechanism among the LGBTQ+ community

Each individual has its own way to deal with difficult emotions and situations. Oftentimes, the coping mechanism adopted by a person, depending on whether they are safe or risky, will impact their mental health. These coping mechanisms tend to be developed during youth and early-adult life. Once a risky coping mechanism is adopted, it is often hard for the individual to get rid of it.

Safe coping-mechanisms, when it comes to mental disorders, involve communication with others, body and mental health caring, support and help seeking.

Because of the high stigmatization they often experience in school, public spaces and society in general, the LGBTQ+ community, and more especially the young people among them are less likely to express themselves and seek for help and support, because of the lack of resources and safe spaces available for them to do so. As a result, LGBTQ+ patients are more likely to adopt risky coping mechanisms then the rest of the population.

These risky mechanisms involve strategies such as self-harm, substance abuse, or risky sexual behavior for many reasons, including; "attempting to get away from or not feel overwhelming emotions, gaining a sense of control, self-punishment, nonverbally communicating their struggles to others." Once adopted, these coping mechanisms tend to stick to the person and therefore endanger even more the future mental health of LGBTQ+ patients, reinforcing their exposure to depression, extreme anxiety and suicide.

Sex differences in medicine

From Wikipedia, the free encyclopedia
 

Sex differences in medicine include sex-specific diseases or conditions which occur only in people of one sex due to underlying biological factors (for example, prostate cancer in males or uterine cancer in females); sex-related diseases, which are diseases that are more common to one sex (for example, breast cancer and systemic lupus erythematosus which occur predominantly in females); and diseases which occur at similar rates in males and females but manifest differently according to sex (for example, peripheral artery disease).

Sex differences should not be confused with gender differences. The US National Academy of Medicine recognizes sex differences as biological at the chromosomal and anatomical levels, whereas gender differences are based on self-representation and other factors including biology, environment and experience. That said, both biological and behavioural differences influence human health, and may do so differentially. Such factors can be inter-related and difficult to separate. Evidence-based approaches to sex and gender medicine try to examine the effects of both sex and gender as factors when dealing with medical conditions that may affect populations differently.

As of 2021, over 10,000 articles had been published addressing sex and gender differences in clinical medicine and related literature. Sex and gender affect cardiovascular, pulmonary and autoimmune systems, gastroenterology, hepatology, nephrology, endocrinology, haematology, neurology, pharmacokinetics, and pharmacodynamics.

Sexually transmitted diseases, which have a significant probability of transmission through sexual contact, can be contracted by either sex. Their occurrence may reflect economic and social as well as biological factors, leading to sex differences in the transmission, prevalence, and disease burden of STDs.

Historically, medical research has primarily been conducted using the male body as the basis for clinical studies. The findings of these studies have often been applied across the sexes, and healthcare providers have traditionally assumed a uniform approach in treating both male and female patients. More recently, medical research has started to understand the importance of taking sex into account as evidence increases that the symptoms and responses to medical treatment may be very different between sexes.

Background

Females and males exhibit many differences in terms of risk of developing disease, receiving an accurate diagnosis, and responding to treatments. A patient's sex has been increasingly recognized as one of the most important modulators of clinical decision making. Sex differences have been found across a broad range of disease areas, including many diseases which are sex-specific. The sex chromosome complement and sex hormone environment are known to be the primary constitutive difference between females and males. The imbalance of gene expression between the X and Y chromosomes is present within virtually all cells in the human body. Sex hormones are crucial in body development and function and also thought to contribute to sex differences in some diseases. It is suspected that many differences between the sexes are also influenced by social, environmental, and psychological factors which are difficult to tease apart from biological ones.

Causes

Sex-related illnesses have various causes:

  • Genetic sex differences start at conception depending on whether an ovum fuses with a sperm cell carrying an X or a Y chromosome. This leads to sex-based differences at the molecular level for all male and female cells.
  • In males, the X chromosome carries only maternal imprints, while in females X chromosomes are present with both maternal and paternal imprints. In female cells, random processes of X-inactivation "turn off" the extra X chromosome. As a result, females, but not males, are mosaics. Female cells may express higher levels of some genes.
  • Sex differences at the chromosome and molecular level exist in all human cells, and persist life-long, independent of sex hormones in the body.
  • Sex-linked genetic conditions that differ in males and females may reflect the effects of genetic damage on an X chromosome. In some cases, the presence of an "extra" X chromosome in female cells may lessen the impact of such damage. In severe cases, males may die during development and females may survive but display a sex-linked illness.
  • The reproductive system develops differently for each sex. Sex-specific parts of the male and female reproductive systems affect the rest of the body and also can be affected differently by diseases.
  • Socially constructed norms relate to gender roles, relationships, positional power, and a wide variety of behaviours. Norms affect people differentially depending on their sex and gender.
  • Different levels of prevention, reporting, diagnosis, and treatment have been observed based on sex and gender.

Examples of sex-related illnesses and disorders in humans

Females

Examples of sex-related illnesses and disorders in human females:

Males

Examples of sex-related illnesses and disorders in male humans:

Top Ten Myths about Neanderthals

Neanderthal Reconstruction

Top Ten Myths about Neanderthals

Neanderthals are generally classified by palaeontologists as the species Homo neanderthalensis , but some consider them to be a subspecies of Homo sapiens ( Homo sapiens neanderthalensis ). The first humans with proto-Neanderthal traits are believed to have existed in Europe as early as 600,000–350,000 years ago, and they died out around 30,000 years ago.

When it comes to behaviors, Neanderthals tend to get a pretty bad rap. However, a plethora of research over the last several years has been breaking down many of the myths associated with this ancient species.

Once depicted as barbaric, grunting, sub-humans, Neanderthals are now known to have had the same or similar levels of intelligence as modern humans. They also had their own distinct culture. Here we examine 10 myths about Neanderthals which have now been proven false.

The belief in the barbaric, grunting, primitive Neanderthal is changing. ( anibal /Adobe Stock)

Myth 1: Neanderthal Tools were not as Good as Tools Made by Modern Humans

The predominant belief in mainstream archaeology over a decade ago was that Neanderthals only utilized very simplistic tools, like sharpened stones. However, research conducted over the last 10 years has revised this perspective based on new archaeological evidence.

An investigation conducted in France , for example, analyzed artifacts unearthed from an archaeological site known as Abri du Maras, in the Middle Rhône Valley. The researchers found Levalloise flakes, which are associated with Neanderthal stone tool technology, traces of twisted fiber, suggesting the manufacture of cordage or string, and six lithic points that appear to be related to complex projectile technology, a development usually only associated with early modern humans.

A second study suggested that Neanderthals even passed on some of their tool-making abilities to humans . Dutch scientists discovered 50,000-year-old tools made from deer ribs in south-west France, which are similar to bone lissoirs or smoothers, still used by leather workers today, and contain a polished tip which creates softer and more water resistant leather when scraped against a hide. The excavated tools are similar to others found at sites occupied by early modern humans around 10,000 years later.

Neanderthal may have taught Homo sapiens new tool making technologies. ( Andy Ilmberger / Adobe Stock)

Modern humans ( Homo sapiens ) appear to have entered Europe with only pointed bone tools but soon after their arrival they started to make lissoirs, providing the first possible evidence that Neanderthals invented the specialized bone tools and passed their know-how on to Homo sapiens.

Myth 2: Neanderthals Spoke through Grunts and Animal Sounds

It was long believed that Neanderthals lacked the necessary cognitive capacity and vocal hardware for speech and language, rendering them incapable of little more than a series of grunts. However, recent research has revealed that Neanderthals most likely had a sophisticated form of speech and language not dissimilar to Homo sapiens .

Researchers utilized the latest 3D X-ray imaging technology to examine a 60,000-year-old Neanderthal hyoid bone discovered in the Kebara Cave in Israel in 1989. The hyoid bone is situated centrally in the upper part of the neck, beneath the mandible but above the larynx and is the foundation of speech. So far, it has only been found to exist in humans and Neanderthals. The results showed that in terms of mechanical behavior, the Neanderthal hyoid was basically indistinguishable from our own, strongly suggesting that this key part of the vocal tract was used in exactly the same way.

Myth 3: Neanderthals Did Not Bury their Dead

It was not so long ago that Neanderthals were considered to be little more than primitive cavemen, and they certainly weren’t considered cultured enough to bury their dead. But that belief has been upended by the discovery of a number of Neanderthal burials over the years. The finding of a 50,000-year-old Neanderthal skeleton in a cave in La Chappele-aux Saints, France revealed that the individual had been carefully placed in a grave and great care had been taken to protect his body from scavengers.

One of the most famous Neanderthal child burials was uncovered in 1961 at Roc de Marsal. The grave was in a remarkable state of preservation, considering its age of 70,000 years. It consisted of the body of a child, approximately three years of age, who had been deposited in a natural depression in the ground, and apparently placed into the form of an arc, lying on its stomach, with a hand to its head and legs bent at 90 degrees, then covered with soil. The idea that Neanderthals buried their dead fits with recent findings that they were capable of developing rich cultural practices.

Myth 4: Neanderthals Did Not Have Homes

There has been this idea that Neanderthals did not have an organized use of space, something that has always been attributed to humans. But archaeologists in Italy have found a collapsed rock shelter which has revealed that Neanderthals kept an organized and tidy home with separate spaces for preparing food, sleeping, making tools, and socializing.

The top level appears to have been used for butchering animals because it contained a high concentration of animal remains. The middle level contained the most traces of human occupation and seems to have been a long-term sleeping area. Artifacts were distributed to avoid clutter around the hearth at the back of the cave.

Finally, the bottom level was a place for shorter stays. Animal bones and stone tools were concentrated at the front rather than the rear of the shelter, suggesting that tool production took place there to take advantage of available sunlight.

Myth 5: Neanderthals were Carnivores who Only Ate Raw Meat

Neanderthals were once depicted as ape-like hominids tearing into the raw flesh of freshly hunted animals. However, recent research conducted by the Catalan Institute for Research and Advanced Studies in Barcelona discovered calcified plaque on Neanderthal fossil teeth found in El Sidrón cave in Spain, which suggested that this extinct human species cooked vegetables and consumed bitter-tasting medicinal plants such as chamomile and yarrow.

Sadly, the prejudiced view of Neanderthal inferiority still persists, as reflected in a statement countering that study by researcher Laura Buck from London’s Natural History Museum:  “The mistake is to think that because you find plant fragments in teeth that they must have got there because these carnivores – in this case Neanderthals – had consumed them as part of a carefully constructed diet or were taken because it was realised that certain herbs and grasses had health-promoting properties. In fact, they may have got there purely because Neanderthals liked to eat the stomach contents of some of the animals they killed.”

According to Buck, Neanderthals simply weren’t intelligent enough to provide themselves with balanced diets or of treating themselves with health-restoring herbs. However, Buck was unable to present any evidence to support her claims and more recent research shows that Neanderthals ate meat, but obviously included plants in their diet as well.

Neanderthals hunted but also gathered their food. ( CSIC Spain )

Neanderthal Myth 6: They were Bad Parents

Until recently, the traditional view saw Neanderthal childhood as harsh, difficult, and dangerous. This perspective was based on preconceptions about Neanderthal inferiority and their inability to protect their children. However, recent research has shown this was not the case.

In a study published in 2014 , a team of archaeologists from the Centre for Human Palaeoecology and Evolutionary Origins at the University of York challenged the traditional perspective and claimed that Neanderthal children experienced strong emotional attachments with their immediate social group, Neanderthals would care for sick children for years, and children played a key role in society, particularly in symbolic expression.

The research team drew upon cultural and social evidence to explore the experience of Neanderthal children. They found, for example, that Neanderthal child burials were more elaborate than those of adults, suggesting strong emotional bonds and the important role that children played in the social group.

Myth 7: Neanderthals had no Cultural Expression

It is often cited in academic literature that cultural expression emerged in the Palaeolithic era, around 30,000 years ago, which rules out Neanderthal artisans since this was around the time they died out. However, evidence suggests that culture flourished much earlier, during the time in which Neanderthals roamed the planet.

Rock art in El Castillo cave in Spain, for example, has been dated to around 40,800 years old, which raises the possibility that some of the paintings could have been made by Neanderthals.  In addition, evidence suggests that the Neanderthals also had music. The oldest musical instrument ever discovered is believed to be the Divje Babe flute, discovered in a cave in Slovenia in 1995, though this has been disputed.

Some prehistoric cave paintings could have been made by Neanderthals. ( nicolasprimola /Adobe Stock)

The item is a fragment of the femur of a cave bear which had been pierced with spaced holes and has been dated at 60,000-43,000 years old. Scientists who could not accept the possibility that Neanderthals were playing music rejected the claim and said that the perfectly spaced and neatly carved holes are the result of the bone fragment having been chewed by an animal. However, the general consensus that the Divje Babe flute is actually a musical instrument has been growing as the view of the Neanderthals from subhuman brutes to more sophisticated hominids is changing.

Myth 8: Neanderthals were Incapable of Showing Care and Empathy

Far from being self-centered individuals incapable of looking after anyone but themselves, there is actually much evidence to show that Neanderthals cared for the sick and old in their communities. The "Old Man of La Chapelle" is the name given to the remains of a Neanderthal male found buried in the limestone bedrock of a small cave near La Chapelle-aux-Saints, in France in 1908. He lived 56,000 years ago and was the first relatively complete skeleton of a Neanderthal ever found.

Scientists estimate he was relatively old by the time he died, as bone had re-grown along the gums where he had lost several teeth, perhaps decades before. He lacked so many teeth that he would have needed his food ground down before he was able to eat it. The old man's skeleton indicates that he also suffered from a number of afflictions, including arthritis, and had numerous broken bones, which would have made movement difficult without assistance. The other members of his group would have had to have taken care of him before his death.

Other Neanderthal remains have shown potentially life-threatening injuries which were completely healed, indicating that the individual who suffered the injuries was nursed back to health by another member of his group.

Myth 9: Neanderthals and Humans Did Not Mix

It was once believed that Neanderthals died out before the emergence of Homo sapiens. However, this was revised when archaeological evidence revealed that there was a cross-over of at least several thousand years, if not longer, during which Neanderthals and modern humans walked the Earth together.

But the idea of interbreeding between the two species was still considered almost blasphemous, and it was not thought to have even been biologically possible. However, in recent years, with the development of techniques to analyze ancient DNA, a number of studies have revealed that Neanderthals and humans did interbreed and up to 20 per cent of Neanderthal DNA lives on in modern humans .

Myth 10: Neanderthals were our Direct Ancestors

There is a common misconception, often propagated by mistaken media reporting, that Neanderthals were the direct ancestors of Homo sapiens . In fact, Neanderthals and modern humans existed side by side as two separate groups.

DNA studies have found that the Neanderthals came from a distinct evolutionary line, and are therefore often referred to as the ‘distant cousins’ of humans. Nevertheless, the genetic mixing between the two species which came about as a result of interbreeding undoubtedly contributed to who we are today.

Top Image: An artist’s reconstruction of a Neanderthal, displayed in the exhibition ‘Britain: One Million Years of the Human Story’. Source: The Trustees of the Natural History Museum, London

By Joanna Gillan

Saturday, February 5, 2022

Metropolitan area

From Wikipedia, the free encyclopedia
Satellite imagery showing the New York metropolitan area at night. Long Island extends to the east of the central core of Manhattan.
 

A metropolitan area or metro is a region consisting of a densely populated urban core and its less-populated surrounding territories sharing industries, commercial areas, transport network, infrastructures and housing. A metro area usually comprises multiple jurisdictions and municipalities: neighborhoods, townships, boroughs, cities, towns, exurbs, suburbs, counties, districts, and even states and nations like the eurodistricts. As social, economic and political institutions have changed, metropolitan areas have become key economic and political regions.

Metropolitan areas include satellite cities, towns and intervening rural areas that are socioeconomically tied to the urban core, typically measured by commuting patterns. Most metropolitan areas are anchored by one core city such as Paris metropolitan area (Paris), Mumbai Metropolitan Region (Mumbai (Bombay)), and New York metropolitan area (New York City). In some cases metropolitan areas have multiple centers of close to equal importance, such as Dallas–Fort Worth metropolitan area (Dallas and Fort Worth), Islamabad–Rawalpindi metropolitan area (Islamabad and Rawalpindi), the Rhine-Ruhr in Germany and the Randstad in the Netherlands.

In the United States, the concept of the metropolitan statistical area has gained prominence. Metropolitan areas may themselves be part of larger megalopolises. For urban centres outside metropolitan areas, that generate a similar attraction at smaller scale for their region, the concept of the regiopolis and respectively regiopolitan area or regio was introduced by German professors in 2006. In the United States, the term micropolitan statistical area is used.

General definition

A metropolitan area combines an urban agglomeration (the contiguous, built-up area) with zones not necessarily urban in character, but closely bound to the center by employment or other commerce. These outlying zones are sometimes known as a commuter belt, and may extend well beyond the urban zone, to other political entities. For example, Islip, New York on Long Island is considered part of the New York metropolitan area.

In practice, the parameters of metropolitan areas, in both official and unofficial usage, are not consistent. Sometimes they are little different from an urban area, and in other cases they cover broad regions that have little relation to a single urban settlement; comparative statistics for metropolitan area should take this into account. The term "Metropolitan" can also refer to a county-level municipal government structure, with some shared services between a central city and its suburbs, which may or may not include the entirety of a metropolitan area. Population figures given for one metro area can vary by millions.

There has been no significant change in the basic concept of metropolitan areas since its adoption in 1950, although significant changes in geographic distributions have occurred since then, and more are expected. Because of the fluidity of the term "metropolitan statistical area," the term used colloquially is more often "metro service area," "metro area," or "MSA" taken to include not only a city, but also surrounding suburban, exurban and sometimes rural areas, all which it is presumed to influence. A polycentric metropolitan area contains multiple urban agglomerations not connected by continuous development. In defining a metropolitan area, it is sufficient that a city or cities form a nucleus with which other areas have a high degree of integration.

See also the many lists of metropolitan areas itemized at § Lists of metropolitan areas.

History

Australia

The Australian Bureau of Statistics uses Greater Capital City Statistical Areas (GCCSAs), which are geographical areas designed to represent the functional extent of each of the eight State and Territory capital cities. They were designed to reflect labour markets, using the 2011 Census "travel to work" data. Labour markets are sometimes used as proxy measures of the functional extent of a city as it contains the majority of the commuting population. GCCSAs replaced "Statistical Divisions" used until 2011.

Other Metropolitan areas in Australia include cross border cities or continuous built-up areas between two or more cities that are connected by an extensive public transport network that allows for commuting for work or services. The following are such conurbations:

Albury-Wodonga

Canberra-Queanbeyan

Newcastle-Sydney-Wollongong

Perth Metropolitan Region-City of Mandurah-Pinjarra

South East Queensland

Melbourne-Geelong

Bangladesh

In Bangladesh, the large population centers which have significant Financial, political and administrative Importance are considered to be as Metropolitan cities, which are governed by City Corporations. In total, there are 12 City Corporations in Bangladesh. 4 of them (Dhaka North City Corporation, Dhaka South City Corporation, Narayanganj City Corporation, Gazipur City Corporation) are part of Greater Dhaka Conurbation .

Brazil

In Brazil, "Metropolitan Regions", "Integrated Development Areas", and "Urban Agglomerations" are created by statute. Each state defines its own legislation for the creation, definition and organization of a metropolitan region. The creation of a metropolitan region is not for any statistical purpose, although the Brazilian Institute of Geography and Statistics (IBGE) uses them in reports. Their main purpose is to improve management of public policies of common interest to all municipalities included within. They do not have any political, electoral or jurisdictional power whatsoever, so citizens do not elect representatives for them.

The IBGE defines also "Immediate Geographic Areas" (formerly termed microregions) which capture the region "surrounding urban centers for the supply of immediate needs of the population". Intended for policy planning purposes, as of March 2021 census data is not tabulated on the level of these Areas, but instead at the municipality or state level.

Canada

Statistics Canada defines a census metropolitan area (CMA) as an area consisting of one or more adjacent municipalities situated around a major urban core. To form a CMA, the metropolitan area must have a population of at least 100,000, at least half within the urban core. To be included in the CMA, adjacent municipalities must have a high degree of integration with the core, as measured by commuter flows derived from census data.

China

In Chinese, there used to be no clear distinction between "megalopolis" (城市群, lit. city cluster) and "metropolitan area" (都市圈) until National Development and Reform Commission issued Guidelines on the Cultivation and Development of Modern Metropolitan Areas (关于培育发展现代化都市圈的指导意见) on Feb 19, 2019, in which a metropolitan area was defined as "an urbanized spatial form in a megalopolis dominated by (a) supercity(-ies) or megacity(-ies), or a large metropolis playing a leading part, and within the basic range of 1-hour commute area."

European Union

The European Union's statistical agency, Eurostat, has created a concept named "larger urban zone" (LUZ). The LUZ represents an attempt at a harmonised definition of the metropolitan area, and the goal was to have an area from which a significant share of the residents commute into the city, a concept known as the "functional urban region".

France

France's national statistics institute, the INSEE, names an urban core and its surrounding area of commuter influence an aire urbaine (official translation: "urban area"). This statistical method applies to agglomerations of all sizes, but the INSEE sometimes uses the term aire métropolitaine (metropolitan area) to refer to France's largest aires urbaines.

Germany

In German definition, metropolitan areas are eleven most densely populated areas in the Federal Republic of Germany. They comprise the major German cities and their surrounding catchment areas and form the political, commercial and cultural centres of the country.

For urban centres outside metropolitan areas, that generate a similar attraction at smaller scale for their region, the concept of the Regiopolis and respectively regiopolitan area or regio was introduced by German professors in 2006.

India

In India, a metropolitan city is defined as one with a population more than 1 million.

Indonesia

In Indonesia, the government of Indonesia defines a metropolitan area as an urban agglomeration where its spatial planning is prioritised due to its highly important influence on the country. Currently, there are 10 metropolitan cities in Indonesia that have been recognized by the government.

Italy

In 2001, Italy transformed 14 provinces of some of the country's largest cities into Metropolitan Cities. Therefore the territory of the Metropolitan City corresponds to that of a normal Italian province.

Japan

In Japan, a metropolitan area (都市圏) is a division set separately from administrative areas in order to define wide urban areas used in the Census conducted by the Statistics Bureau of the Ministry of Internal Affairs and Communications.

The Greater Tokyo Area is the most populous metropolitan area in the world.

If the central cities are next to each other, the areas are integrated into one large area.

  • Surrounding Municipality (周辺市町村, lit. 'surrounding cities, towns and villages')
    • Those are municipalities with ratios of the number of people commuting to the central city over 15 years old being 1.5% or more of the permanent population of and close to the central cities.

If a municipality is surrounded by the surrounding municipalities, it will be a surrounding municipality.

Mexico

Metropolitan areas are known as zonas metropolitanas in Mexico. The National Population Council (CONAPO) defines them as:

  • a set of two or more municipalities where a city with a population of at least 100,000 is located, and whose urban area, functions and activities exceed the limits of the municipality.
  • municipalities with a city of more than 500,000 inhabitants, or a city of more than 200,000 inhabitants located in the northern and southern border areas and in the coastal zone.
  • municipalities where state capitals are located, if they are not already included in a metropolitan zone.

As of 2018, there are 74 zonas metropolitanas in Mexico. 75.1 million people, 62.8% of the country population, live within a metropolitan area.

Pakistan

Pakistan has nine metropolitan areas with populations greater than a million. Seven of these are entirely in Punjab including Lahore, Faisalabad, Gujranwala, Multan, Bahawalpur, Sargodha, and Sialkot; one (Islamabad-Rawalpindi is split between Punjab and the Islamabad Capital Territory; two are located in Sindh, including Karachi, the largest metropolitan area in the country, and Hyderabad; one in Khyber Pakhtunkhwa: Peshawar; and the final in Balochistan: Quetta.

Philippines

The Philippines currently has three metropolitan areas defined by the National Economic and Development Authority (NEDA). These metropolitan areas are separated into three main geographical areas; Metro Manila (which is located in Luzon), Metro Cebu (which is located in Visayas), and Metro Davao (which is located in Mindanao). The official definition of each area does not necessarily follow the actual extent of continuous urbanization. For example, the built-up area of Metro Manila has long spilled out of its officially defined borders into the adjacent provinces of Bulacan, Rizal, Laguna, and Cavite. The number of metropolitan areas in the Philippines was reduced from 13 in 2007 to the current three based from the 2017–2022 Philippine Development Plan by NEDA. The other 10 metropolitan areas were Metro Angeles, Metro Bacolod, Metro Baguio, Metro Batangas, Metro Cagayan de Oro, Metro Dagupan, Metro Iloilo–Guimaras, Metro Butuan, Metro Naga, and Metro Olongapo.

South Africa

The Greater Johannesburg metropolitan area is the largest metropolitan area in South Africa. Its population was over 9.6 million as of the 2011 South Africa Census, in contrast to its urban area, which consisted of approximately 7.9 million inhabitants as of 2011. Conversely, metropolitan municipalities in South Africa are defined as commonly governed areas of a metropolitan area. The largest such metropolitan municipal government entity in South Africa is the City of Johannesburg Metropolitan Municipality, which presided over nearly 5 million people as of 2016. However, the Greater Johannesburg metropolitan area houses roughly ten times the population of its core municipal city of Johannesburg, which contained 957,441 people as of the 2011 census.

Sweden

Sweden defines a metropolitan area as a group of municipalities, based on statistics of commuting between central municipalities and surrounding municipalities and taking into account existing planning cooperation in the country's three geographic regions. They were defined around 1965. In 2005, a number of further municipalities were added to the defined areas.

Turkey

The word metropolitan describes a major city in Turkey like Istanbul, a city that is dominant to others both financially and socially. There are 30 officially defined "state metropolitan areas" in Turkey, for governing purposes.

United Kingdom

The United Kingdom government's Office for National Statistics defines "travel to work areas" as areas where "at least 75% of an area's resident workforce work in the area and at least 75% of the people who work in the area also live in the area".

United States

As of February 28, 2013, the United States Office of Management and Budget (OMB) defined 1,098 statistical areas for the metropolitan areas of the United States and Puerto Rico. These 1,098 statistical areas comprise 929 Core-Based Statistical Areas (CBSAs) and 169 Combined Statistical Areas (CSAs). The 929 Core-Based Statistical Areas are divided into 388 Metropolitan Statistical Areas (MSAs – 381 for the U.S. and seven for Puerto Rico) and 541 Micropolitan Statistical Areas (μSAs – 536 for the U.S. and five for Puerto Rico). The 169 Combined Statistical Areas (166 for the U.S. and three for Puerto Rico) each comprise two or more adjacent Core Based Statistical Areas.

The Office of Management and Budget defines a Metropolitan Statistical Area as one or more adjacent counties or county equivalents that have at least one urban area of at least 50,000 population, plus adjacent territory that has a high degree of economic and social integration with the core as measured by commuting ties. The OMB then defines a Combined Statistical Area as consisting of various combinations of adjacent metropolitan and micropolitan statistical areas with economic ties measured by commuting patterns. The Office of Management and Budget further defines a core-based statistical area (CBSA) to be a geographical area that consists of one or more counties (or equivalents) anchored by an urban center of at least 10,000 people plus adjacent counties that are socioeconomically tied to the urban center by commuting.

Operator (computer programming)

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Operator_(computer_programmin...