Compared with the heterosexual population, LGBT people today score lower on key mental health indices. Current scholarship relies on Sexual Minority Stress Theory (SMST) to explain the disparity as resulting from stigma and discrimination. Historically informed scholars question this approach, pointing to the ground-breaking work of UCLA psychologist Evelyn Hooker, who showed in the 1950s (an era of far worse discrimination) that same-sex attracted individuals scored near average in terms of mental health indices, a finding that led to homosexuality being de-listed as a psychiatric disorder in the early 1970s.
A new study published in Psychological Medicine has challenged SMST from another angle, conducting a systematic meta-analysis of 17 empirical studies in which twins or non-twin siblings reported on both their sexual orientation and their mental health. To the extent that heterosexual genetic relatives reared with non-heterosexual persons also have worse mental health, SMST is falsified. The researchers found that the mental health disparity between non-heterosexual and heterosexual persons is reduced by up to two-thirds once familial background factors are accounted for by comparing monozygotic twins discordant for sexual orientation. This suggests that shared familial factors, both genetic and environmental, are the most important causes of poor mental health in non-heterosexual persons. Dysfunctional families generate more than their share of kids with mental health struggles and kids who avoid pursuing traditional heterosexual family formation in their own lives.
