14th February 2025

Epidemiology and aetiology of depressive disorders

Around 10-20% of the population will experience a depressive episode during their lifetime. Incidence is increasing in the younger population, and although prevalence is higher in females, it is believed that males are underdiagnosed.

Risk factors include family history of depressive or anxiety disorders, adverse childhood or adult experiences (in particular loss events), anxious personality, divorce, low socioeconomic status, and unemployment. Those with chronic, severe or painful organic illness are also more likely to develop a depressive disorder. Concurrent psychiatric illness is common, such as anxiety disorders, substance or alcohol misuse, or personality disorders.