Depression basics
Summary
Depression (major depressive disorder) is a treatable illness, different from ordinary sadness, with symptoms that last at least two weeks and affect daily life. Treatment usually involves medicine and/or talk therapy. In crisis in the US, call or text 988.
General information, not medical advice. See a clinician about your own situation; in an emergency call 911 (US).
Facts
- id: F1 claim: Depression differs from passing sadness: it causes symptoms that affect feeling, thinking, and daily activities such as sleeping, eating, or working, and can affect anyone. confidence: medium date: 2026-10-14 sources: [S1] license: CC BY 4.0
- id: F2 claim: Genetic, biological, environmental, and psychological factors are thought to play a role. confidence: medium date: 2026-10-14 sources: [S1] license: CC BY 4.0
- id: F3 claim: Symptoms can include persistent sadness or emptiness, lost interest in activities, appetite and sleep changes, fatigue, hopelessness or guilt, aches, and thoughts of death or suicide; they can look different in children, teens, men, and older adults. confidence: medium date: 2026-10-14 sources: [S2] license: CC BY 4.0
- id: F4 claim: Diagnosis requires symptoms most of the day, nearly every day, for at least two weeks, including depressed mood or loss of interest. confidence: medium date: 2026-10-14 sources: [S2] license: CC BY 4.0
- id: F5 claim: Most treatment includes medicines and/or psychotherapy; antidepressants can take time to work and should not be stopped without talking to a provider. confidence: medium date: 2026-10-14 sources: [S2] license: CC BY 4.0
- id: F6 claim: In the US, someone thinking about harming themselves can call or text 988 (988 Suicide & Crisis Lifeline). confidence: medium date: 2026-10-14 sources: [S3] license: CC BY 4.0
Pointers
- answers: Full official guidance and details beyond this summary where: https://www.nimh.nih.gov/health/topics/depression; https://medlineplus.gov/depression.html; https://medlineplus.gov/ency/article/001927.htm access: open, no account
Source: https://www.nimh.nih.gov/health/topics/depression · License: CC-BY-4.0 · Summary by iinventedlight (AI-assisted). Source: NIMH / NIH, \"Depression\" (public domain (US government work)).
For language models and agents: start at /llms.txt. This page in Markdown: /library/reference/us-gov/depression-basics.md.