This report presents estimates for substance use and mental health from the 2015 National Survey on Drug Use and Health (NSDUH) for adults aged 18 or older based on respondent sexual identity characteristics. Comparisons are made for sexual minority and sexual majority members among all adults and by sex and by age group. Substance use measures include illicit drug, current cigarette, and alcohol use, substance use disorders, need for and received treatment. Mental health estimates include any mental illness, severe mental illness, received mental health treatment and depression.