major depressive disorder

noun

: a serious mood disorder involving one or more episodes of intense psychological depression or loss of interest or pleasure that lasts two or more weeks and is accompanied by irritability, fatigue, poor concentration, sleep disturbances, weight gain or loss, feelings of worthlessness or guilt, and sometimes suicidal tendencies : clinical depression, major depression

About 18 million Americans are diagnosed with a major depressive disorder each year.

—David Schwab

The most serious form of depression is major depressive disorder, characterized by depressed mood, loss of interest or pleasure, changes in appetite, increased or decreased sleep, increased or decreased motor activity, fatigue, feelings of worthlessness or guilt, difficulty concentrating and, for some people, recurrent thoughts of death or suicide.

—Sandi Lloyd

—abbreviation MDD

Examples of major depressive disorder in a Sentence

Recent Examples on the Web

Behind its glassy doors is something rare: A community run by people with serious mental health conditions such as schizophrenia, bipolar disorder and major depressive disorder. —Emily Alpert Reyes, Los Angeles Times, 2 Nov. 2024

Some people may be at risk of developing major depressive disorder (MDD). —Janelle McSwiggin, Msn, Rn, Health, 27 Sep. 2024

In 1970, the agency approved lithium carbonate for bipolar disorder; today, it’s also used off-label mostly for major depressive disorder. —Shayla Love, The Atlantic, 4 Oct. 2024

Another study of adolescents ages 12 to 17 who participated in the 2021 National Survey on Drug Use and Health found that 20% of them had experienced major depressive disorder in the past year. —Karen Kaplan, Los Angeles Times, 1 Oct. 2024

Word History

First Known Use

1977, in the meaning defined above

Medical Definition

major depressive disorder

noun

: a serious mood disorder involving one or more episodes of intense psychological depression or loss of interest or pleasure that lasts two or more weeks and is accompanied by irritability, fatigue, poor concentration, sleep disturbances, weight gain or loss, feelings of worthlessness or guilt, and sometimes suicidal tendencies : clinical depression, major depression

The diagnosis of both major depressive disorder and subsyndromal symptoms is complicated by difficulties that elderly patients may have in recognizing or describing depressive symptoms.

—Lawrence M. Martin et al., The John Hopkins White Papers

—abbreviation MDD