This report describes the results of data collection efforts conducted by the Substance Abuse and Mental Health Services Administration (SAMHSA) and the Centers for Disease Control and Prevention (CDC) related to the behavioral health (mental health and substance use) of residents of the Gulf Coast affected by the Deepwater Horizon oil spill. The data collection efforts described in this report, which were funded by BP, focused on residents of the counties or parishes in Alabama, Florida, Louisiana, and Mississippi that were most directly affected by the spill. The report uses data from SAMHSA\'s National Survey on Drug Use and Health (NSDUH) and Gulf States Population Survey (GSPS) from CDC.