The NHSDA is the largest survey of its kind conducted in the United States and serves as the primary source of information on substance use and abuse in the country. The five main objective of the report are to: (1) estimate prevalence rates and characteristics of adults receiving mental health treatment; (2) identify treatments received; (3) identify types of facilities for outpatient and inpatient treatment; (4) examine relationships between mental health treatment and substance use, dependence/abuse, and substance abuse treatment; and (5) describe characteristics of persons reporting a perceived unmet need for mental health treatment. Following the introduction in chapter 1, chapter 2 describes the demographic and socioeconomic characteristics of persons receiving mental health treatment. Data for 2000 and 2001 indicate that 10.5 percent of the United States adult population aged 18 years or older received treatment for a mental or emotional problem within the 12 months prior to the survey; 8.3 percent received prescription medication to treat the problem. Chapter 3 compares the characteristics of adults receiving different types of mental health treatment. Chapter 4 reports on the characteristics of persons receiving outpatient treatments. Chapter 5 presents the characteristics of persons receiving inpatient treatment, which reveals that almost 44 percent of adults hospitalized for mental health treatment during the study period spent 5 or more nights in these facilities. Chapter 6 discusses rates of mental health treatment among substance users and nonusers and describes the co-occurrence of mental health and substance abuse treatments. Adults who received substance abuse treatment had 2 to 5 times higher rates of mental health treatment during the past year than those who never received substance abuse treatment. Chapter 7 presents findings on the perceived unmet need for mental health treatment. Tables, figures, references, appendix