Gender dysphoria (GD), or gender identity disorder (GID), is the distress a person experiences as a result of the sex and gender they were assigned at birth. In this case, the assigned sex and gender do not match the person's gender identity, and the person is transgender. There is evidence suggesting that twins who identify with a gender different from their assigned sex may do so not only due to psychological or behavioral causes, but also biological ones related to their genetics or exposure to hormones before birth. Estimated rates of those with a transgender identity range from a lower bound of 1:2000 (or about 0.05%) in the Netherlands and Belgium to 0.5% of Massachusetts adults to 1.2% of New Zealand high-school students. These numbers are based on those who identify as transgender. It is estimated that about 0.005% to 0.014% of people assigned male at birth and 0.002% to 0.003% of people assigned female at birth would be diagnosed with gender dysphoria, based on 2013 diagnostic criteria, though this is considered a modest underestimate. Research indicates people who transition in adulthood are up to three times more likely to be male assigned at birth, but that among people transitioning in childhood the sex ratio is close to 1:1. Gender dysphoria is classified as a disorder under dual role transvestism in the 2017 ICD-10 CM. GID was reclassified to gender dysphoria by the DSM-5. Some transgender people and researchers support declassification of GID because they say the diagnosis pathologizes gender variance, reinforces the binary model of gender, and can result in stigmatization of transgender individuals. The official reclassification as gender dysphoria in the DSM-5 may help resolve some of these issues, because the term gender dysphoria applies only to the discontent experienced by some persons resulting from gender identity issues. The American Psychiatric Association, publisher of the DSM-5, states that "gender nonconformity is not in itself a mental disorder. The critical element of gender dysphoria is the presence of clinically significant distress associated with the condition." The main psychiatric approaches to treatment for persons diagnosed with gender dysphoria are psychotherapy or supporting the individual's preferred gender through hormone therapy, gender expression and role, or surgery. Symptoms of GD in children may include any of the following: disgust at their own genitalia, social isolation from their peers, anxiety, loneliness and depression. According to the American Psychological Association, transgender children are more likely to experience harassment and violence in school, foster care, residential treatment centers, homeless centers and juvenile justice programs than other children. Adults with GD are at increased risk for stress, isolation, anxiety, depression, poor self-esteem and suicide. Studies indicate that transgender people have an extremely high rate of suicide attempts; one study of 6,450 transgender people in the United States found 41% had attempted suicide, compared to a national average of 1.6%. It was also found that suicide attempts were less common among transgender people who said their family ties had remained strong after they came out, but even transgender people at comparatively low risk were still much more likely to have attempted suicide than the general population. Transgender people are also at heightened risk for certain mental disorders such as eating disorders.