Depression
Basics
Description
Primary mood disorder characterized by a sustained feeling of sadness and/or decreased interest in all or most activities once enjoyed, which represents a change from previous state
Epidemiology
Prevalence
- Lifetime prevalence of major depressive disorder (MDD) is 20% (1).
- Low risk before early teens; highest prevalence in teens and young adults (17% of adults 18 to 25 years old reporting a major depressive episode and 7.1% of ≥26 years old in 2020)
Etiology and Pathophysiology
Pathophysiology is poorly understood.
Genetics
Twin studies suggest 37% concordance.
Risk Factors
- Female > male (2:1)
- History of anxiety
- Substance abuse
- Adverse life events
- First-degree relative or spouse with depression, bipolar, suicide, substance abuse
- Presence of chronic medical conditions
General Prevention
Physical activity lowers risk for depression (2).
Commonly Associated Conditions
Bipolar disorder, cyclothymic disorder, grief reaction, anxiety disorders, somatoform disorders, schizophrenia/schizoaffective disorders, conduct disorder, substance abuse, PTSD, fibromyalgia, chronic pain, CAD, MS, diabetes, dementia
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