What is depression?
Why does depression not have just one cause?
Biological, psychological and social influences can interact. A stressful event may play a role, but depression can also occur without an obvious trigger. General patterns do not automatically explain an individual person’s experience. [1][2]
General information for adults. Not medical or psychotherapeutic advice; not a substitute for examination, diagnosis or treatment.
Sources & editorial status
- IQWiG · InformedHealth.org: Depression ↗
Plain-language overview. Used for terminology, symptoms and course.
- WHO: Depressive disorder (depression) ↗
International overview. Used for the distinction from mood changes and contributing factors.
Compiled from an existing article: 31 October 2026. Source comparison in the article: 29 October 2026. Prepared with AI assistance; independent medical review is pending. Editorial compilation; independent medical expert review has not taken place.
Editorial responsibility: Mario V.W.B.R. Obst. Known limitations and the use of each source are explained alongside the reference. A source-comparison date is not the publication date of the original source.