Some 45.9 million, or around 1 in 5 American adults (age 18 and over) experienced a mental illness in the past year, according to the US government’s latest National Survey on Drug Use and Health, released this month.

The survey, published by the Substance Abuse and Mental Health Services Administration (SAMHSA), finds that the rate of mental illness among 18 to 25-year-olds was more than twice as high as among people aged 50 and over (29.9% versus 14.3% respectively).

The survey report defines mental illness as having a diagnosable mental, behavioral or emotional disorder based on criteria given in DSM-IV (the Diagnostic and Statistical Manual of Mental Disorders edition IV, published by the American Psychiatric Association, APA, in 1994). The definition excludes developmental and substance use disorders.

According to the World Health Organization (WHO), in developed countries mental illness accounts for more disability than any other group of illnesses, including heart disease and cancer.

The economic impact of mental illness in the US is high: estimates suggest it came to about $300 billion in 2002.

The US National Survey on Drug Use and Health (NSDUH) includes about 67,500 people (age 12 and over) throughout the country every year.

The latest survey (2010 NSDUH) also found:

  • Adult women were more likely to have experienced mental illness in the past year than adult men (23 versus 16.8%).
  • Substance dependence and abuse was higher among people with mental illness (20% versus 6.1% compared to those without mental illlness).
  • 11.4 million adults (5% of the adult population) suffered from a serious mental illness in the past year (one that leads to a serious functional impairment that substantially interferes or limits one or more major life activities).
  • These had an even higher rate of substance dependence or abuse (25.2%).

SAMHSA Administrator Pamela S. Hyde said in a press statement that:

“These data underscore the importance of substance abuse treatment as well.”

However, “Mental illnesses can be managed successfully, and people do recover,” said Hyde, adding that the government “is working to promote the use of mental health services through health reform. People, families and communities will benefit from increased access to mental health services.”

She also said mental illness is not an “isolated public health problem”. It often co-exists with other diseases such as cardiovascular conditions, diabetes, obesity and cancer. It is also linked to risk behavior such as physical inactivity, smoking, excessive drinking, and insufficient sleep. And if you treat the mental illness you often succeed in reducing the effects of the other disorders, said Hyde.

The report shows that 39.2%, or about 4 in 10, people experiencing any mental illness received mental health services during 2010. For those with serious mental illness, the rate of receiving services was considerably higher at 60.8%.

The report also mentions that an estimated 8.7 million adults had seriously contemplated suicide in the past year, including 2.5 million who made plans to kill themselves and 1.1 million who tried.

The report also highlights some important mental health issues among 12 to 17-year-olds. For 2010 it finds that 1.9 million youngsters (8% of 12 to 17-year-olds) had experienced a major depressive episode in the past year. A major depressive episode is one that lasts for at least 2 weeks and is characterized by loss of interest or pleasure in daily activities, and which meets at least four of the seven symptom criteria laid out in DSM-IV.

And, reflecting the same pattern in the figures on adults, the report shows that young people in this age group who experienced a major depressive episode in the past year had more than twice the rate of illicit drug use in the past year (37.2%) compared to peers who had not had a major depressive episode during the same period (17.8%).

Dr Ileana Arias, Principal Deputy Director of the US Centers for Disease Control and Prevention (CDC) said the report “provides further evidence that we need to continue efforts to monitor levels of mental illness in the United States in order to effectively prevent this important public health problem and its negative impact on total health”.

If you are in crisis or know someone who is and who may be at immediate risk of suicide, then SAMHSA urges that you call the National Suicide Prevention Lifeline 1-800-273-TALK (8255), or go to their website at

The hotline is funded by SAMHSA and provides immediate, round-the-clock, every day of the year, free and confidential counseling to anyone in need throughout the United States.

If you are outside the US then try this website Befrienders International.

In the UK, contact The Samaritans.

Written by Catharine Paddock PhD