- Major depressive episodes in lifetime or past year were assessed in SAMHSA's National Survey on Drug Use and Health among young adults aged 18 to 25. A major depressive episode was defined using the DSM-IV diagnostic criteria which specifies a period of two weeks or longer during which there is either depressed mood or loss of interest or pleasure and at least four other symptoms that reflect a change in functioning (such as problems with sleeping, eating, energy, concentration, and self image).
- Data from SAMHSA's National Surveys on Drug Use and Health were used to examine the following among young adults in the past year: major depressive episode, initiation of alcohol or illicit drug use, and the association between such new alcohol and/or illicit drug use and major depressive episode.
- Combined data from SAMHSA's 2005 and 2006 National Surveys on Drug Use and Health found an annual average of 9.4% of young adults (about 3 million) had experienced at least one major depressive episode during the past year. Rates of major depressive episode varied by gender, racial group, and Hispanic status.