Andrew Mattison

Andrew Michael Mattison (August 5, 1948 – December 29, 2005) was an American medical psychologist and researcher. He performed influential research in both clinical and social aspects of sexology, as well as drug use. He received his Ph.D. from United States International University The book argued that gay male relationships have particular tendencies distinct from other categories of sexual relationships, an innovative thesis that encouraged the growth of a new field, homosexuality studies. However, the book was also used by anti-gay marriage activists in legal arguments.

Career Mattison later began studying the use of party drugs by gay men, a controversial subject, which eventually led to a more thorough investigation of drug use in general.

He died of stomach cancer at the age of 57.