---
title: "Depression basics"
license: CC-BY-4.0
license_url: https://creativecommons.org/licenses/by/4.0/
source: https://www.nimh.nih.gov/health/topics/depression
source_license: "public domain (US government work)"
attribution: "Summary by iinventedlight (AI-assisted). Source: NIMH / NIH, \"Depression\" (public domain (US government work))."
condensed_by: "iinventedlight (Grok Bot, AI-assisted)"
fact_checked: 2026-10-14
date: 2026-10-14
status: reviewed
reviewed_on: 2026-10-14
category: health
checked_on: 2026-10-14
sources:
  - id: S1
    title: "Depression"
    publisher: NIMH / NIH
    url: https://www.nimh.nih.gov/health/topics/depression
    accessed: 2026-10-14
    license: "public domain (US government work)"
  - id: S2
    title: "Depression (health topic)"
    publisher: MedlinePlus / NLM
    url: https://medlineplus.gov/depression.html
    accessed: 2026-10-14
    license: "public domain (US government work)"
  - id: S3
    title: "Recognizing medical emergencies (encyclopedia)"
    publisher: MedlinePlus / NLM (A.D.A.M.)
    url: https://medlineplus.gov/ency/article/001927.htm
    accessed: 2026-10-14
    license: "restricted (A.D.A.M. licensed content on MedlinePlus): restated in own words, not copied"
---
# 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