This report by the Substance Abuse and Mental Health Services Administration (SAMHSA), developed using data from the 2008 National Survey of Drug Use and Health (NSDUH) found that 8.3 million adults (3.7 percent) had serious suicidal thoughts in the past year, 2.3 million (1.0 percent) made a suicide plan, and 1.1 million (0.5 percent) attempted suicide.  The study also found that younger adults were more likely to consider suicide that older adults and that only 62.3 percent of those who attempted suicide last year received medical attention.

From the report:

Suicidality is a major public health problem that affects many Americans and their families every year. Suicidality ranges from suicide ideation (i.e., thoughts of suicide and making suicide plans) to suicide attempts to completed suicide. Over 32,000 adults committed suicide in 2006; however, these represent only a fraction of the individuals who consider or attempt suicide. Gaining a better understanding of suicidal thoughts and behaviors among adults may help to identify individuals at risk for suicide, to inform the development of screening tools, and to inform mental health and general practitioners on treatment planning.

Responding to a need for national data on the prevalence of suicidality, a brief series of questions on suicidal thoughts and behaviors was added to the National Survey on Drug Use and Health (NSDUH) questionnaire in 2008. In previous NSDUHs, suicidality questions were asked in the module on major depressive episode (MDE), and suicidality estimates could be generated only for persons who met the criteria for MDE. The new 2008 questions ask all adult respondents aged 18 or older if they had serious thoughts of suicide in the past year. If they had serious thoughts of suicide, respondents were asked if they made plans to commit suicide and if they attempted suicide in the past year. If they reported having made a suicide attempt, respondents were asked if they received medical attention for their suicide attempt; if they received medical attention, they were asked if they stayed in a hospital overnight or longer for their suicide attempt.

This issue of The NSDUH Report examines suicidal thoughts and behaviors among adults aged 18 or older; data are presented by age group, gender, and past year substance use disorder. All findings in the report are based on 2008 data.

Substance Abuse and Mental Health Services Administration (SAMHSA) Office of Applied Studies (OAS) & RTI International. (2009). The NSDUH Report: Suicidal Thoughts and Behaviors among Adults.

Full report: http://oas.samhsa.gov/2k9/165/Suicide.htm