1 In 5 U.S. Adults Had Mental Illness Last Year: Report

One in five American adults has experienced mental illness in the last year, according to a new government report, with mental illness being more than twice as high among younger adults (ages 18 to 25) than older adults (age 50 and older).

The report, conducted by the Substance Abuse and Mental Health Services Administration (SAMHSA), showed that 29.9 percent of 18- to 25-year-olds experienced mental illness in the last year, compared with 14.3 percent of people age 50 and older.

In addition, women were more likely to have experienced mental illness than men in the last year, with 23 percent of women reporting mental illness compared with 16.8 percent of men.

SAMHSA defined mental illness as having diagnosable disorder that is based on the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV).

"Mental illness is a significant public health problem in itself, but also because it is associated with chronic medical diseases such as cardiovascular disease, diabetes, obesity, and cancer, as well as several risk behaviors including physical inactivity, smoking, excessive drinking, and insufficient sleep," Ileana Arias, Ph.D., principal deputy director of the Centers for Disease Control and Prevention, said in a statement.

The report shows that more efforts are needed to monitor mental illness in order to have effective prevention, Arias added.

About four in 10 people (39.2 percent) received services to help them with their mental illness, and 60.8 percent of people with a serious mental illness received services, the report said.

Researchers gained some insight into suicide and thoughts of suicide through the report. They found that about 8.7 million Americans contemplated suicide in the last year, while 2.5 million people actually made plans to commit suicide and 1.1 million people attempted suicide.

In addition, 8 percent of teens between ages 12 and 17 reported that they had had a major depressive episode over the last year, according to the report.

For the full results, click here.

Last year, a study in the Archives of General Psychiatry showed that the United States has the highest bipolar disorder rate in an 11-nation study, Health.com reported. The lifetime rate for bipolar disorder in the U.S. was 4.4 percent in that study, compared with India's lowest rate of 0.1 percent.