Charles Silverstein, a psychologist who helped achieve one of the most significant victories of the gay rights movement by persuading the American Psychiatric Association in 1973 to declassify homosexuality as a mental illness, died Jan. 30 at his home in New York City. He was 87. He had lung cancer, said his executor, Aron Berlinger. Dr. Silverstein spent decades of his life — as an activist, a psychologist and an author — advancing the cause of gay rights. He had felt the sting of discrimination and the burden of shame as a gay man who came of age at a...