American Psychiatric Association classifies homosexuality as mental disorder in DSM-I

The American Psychiatric Association publishes the Diagnostic and Statistical Manual of Mental Disorders (DSM-I), classifying homosexuality as a mental illness under Sexual Deviation. This designation pathologizes same-sex attraction and provides medical legitimacy to efforts to cure or convert people away from homosexuality. The classification remains in DSM-II published in 1968, providing the medical and psychiatric basis for conversion therapy practices throughout the 1950s-1970s.