Senior author Deborah Hasin, a professor of clinical epidemiology at the Mailman School of Public Health at Columbia University, and colleagues at the New York state Psychiatric Institute and Harvard University analyzed data from the National Epidemiologic Survey on Alcohol and Related Conditions.
Participants were initially interviewed from 2001-2002 and again during 2004-2005, at which time participants' sexual orientation was assessed.
Institutional discrimination is characterized by societal-level conditions that limit opportunities and access to resources by socially-disadvantaged groups, Hasin said.
The researchers examined whether lesbian, gay and bisexual individuals living in states that instituted constitutional amendments banning gay marriage in 2004 and 2005 elections showed evidence of increased rates of psychiatric disorders between 2001-2002 and 2004-2005, the study authors said.
Among study participants living in the states banning same-sex marriage, the prevalence of mood disorders, generalized anxiety disorder and alcohol use disorders increased significantly between 2001-2002 to 2004-2005, with the greatest increase, more than 200 percent, in generalized anxiety disorder.
The findings are published in the American Journal of Public Health.