Mental disorders are common in the United States and internationally. An estimated 22.1 percent of Americans ages 18 and older — about 1 in 5 adults — suffer from a diagnosable mental disorder in a given year.¹ When applied to the 1998 U.S. Census residential population estimate, this figure translates to 44.3 million people. ² In addition, 4 of the 10 leading causes of disability in the U.S. and other developed countries are mental disorders-major depression, bipolar disorder, schizophrenia, and obsessive-compulsive disorder. ³ Many people suffer from more than one mental disorder at a given time.

In the U.S., mental disorders are diagnosed based on the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV). ⁴

Depressive Disorders

Depressive disorders encompass major depressive disorder, dysthymic disorder, and bipolar disorder. Bipolar disorder is included because people with this illness have depressive episodes as well as manic episodes.

• Approximately 18.8 million American adults, ⁵ or about 9.5 percent of the U.S. population age 18 and older in a given year, ¹ have a depressive disorder.
• Nearly twice as many women (12.0 percent) as men (6.6 percent) are affected by a depressive disorder each year. These figures translate to 12.4 million women and 6.4 million men in the U.S. ⁵
• Depressive disorders may be appearing earlier in life in people born in recent decades compared to the past.⁶
• Depressive disorders often co-occur with anxiety disorders and substance abuse. ⁷

Major Depressive Disorder

• Major depressive disorder is the leading cause of disability in the U.S. and established market economies worldwide. ³
• Major depressive disorder affects approximately 9.9 million American adults,⁵ or about 5.0 percent of the U.S. population age 18 and older in a given year. ¹
• Nearly twice as many women (6.5 percent) as men (3.3 percent) suffer from major depressive disorder each year. These figures translate to 6.7 million women and 3.2 million men. ⁵
• While major depressive disorder can develop at any age, the average age at onset is the mid-20s. ⁴

Dysthymic Disorder

• Symptoms of dysthymic disorder (chronic, mild depression) must persist for at least 2 years in adults (1 year in children) to meet criteria for the diagnosis. Dysthymic disorder affects approximately 5.4 percent of the U.S. population age 18 and older during their lifetime. ¹ This figure translates to about 10.9 million American adults. ⁵
• About 40 percent of adults with dysthymic disorder also meet criteria for major depressive disorder or bipolar disorder in a given year. ¹
• Dysthymic disorder often begins in childhood, adolesc.ence, or early adulthood. ⁴

Bipolar Disorder

• Bipolar disorder affects approximately 2.3 million American adults, ⁵ or about 1.2 percent of the U.S. population age 18 and older in a given year. ¹
• Men and women are equally likely to develop bipolar disorder. ⁵
• The average age at onset for a first manic episode is the early 20s. ⁴

Suicide

• In 1997, 30,535 people died from suicide in the U.S.⁸
• More than 90 percent of people who kill themselves have a diagnosable mental disorder, commonly a depressive disorder or a substance abuse disorder. ⁹
• The highest suicide rates in the U.S. are found in white men over age 85. ⁸
• The suicide rate in young people increased dramatically over the last few decades. In 1997, suicide was the 3rd leading cause of death among 15 to 24 year olds. ⁸
• Four times as many men than women commit suicide; ⁸ however, women attempt suicide 2-3 times as often as men. ¹⁰

Schizophrenia

• Approximately 2.2 million American adults, ² or about 1.1 percent of the population age 18 and older in a given year, ¹ have schizophrenia.
• Schizophrenia affects men and women with equal frequency.¹¹
• Schizophrenia often first appears earlier in men, usually in their late teens or early 20s, than in women, who are generally affected in their 20s or early 30s.¹¹