Woman sitting on a bed with her head in her hand, appearing stressed or exhausted, next to a phone on a bedside table.

Depression

Depression is a mood disorder characterized by persistent sadness, lack of interest in activities, and feelings of hopelessness. It can affect sleep, appetite, energy levels, and concentration. Without treatment, it may interfere significantly with daily functioning and quality of life. Persistent sadness, loss of interest, fatigue, and changes in sleep or appetite that affect daily life.