Mental Health

Major Depressive Disorder

Medically reviewed by Sample Data Updated August 2026

Overview

Major depressive disorder is a mood disorder causing persistent feelings of sadness and loss of interest.

Symptoms

Low mood, fatigue, changes in appetite or sleep, and difficulty concentrating.

Causes

Thought to involve a combination of genetic, biological, and environmental factors.

Diagnosis

Diagnosed by a healthcare provider based on symptoms present for at least two weeks.

Treatment

Psychotherapy, medication, or a combination of both are commonly used.

Prevention

Maintaining social connections and healthy routines may help lower risk of recurrence.