Major Depressive Disorder
- Depressed mood and/or anhedonia as gateway symptoms
- At least 2 weeks duration with functional impairment
- Lifetime prevalence approximately 20%
- Must rule out bipolar depression, medical causes, and substance-induced mood changes
- Severity ranges from mild functional decline to psychotic features
Red Flags & Key Clinical Considerations
Suicidality
Recurrent thoughts of death, suicidal ideation with or without plan/intent. Changes the acuity of the entire clinical picture. Always assess directly, patients often don't volunteer this information.
Psychotic Features
Severe depression can produce mood-congruent delusions (guilt, worthlessness, poverty, somatic decay) and hallucinations. Patients rarely volunteer psychotic symptoms. Ask directly in any severely depressed patient, this fundamentally changes the diagnostic picture and treatment approach.
Bipolar Spectrum Warning Signs
Young age of onset, family history of bipolar disorder, antidepressant-induced agitation or mania, multiple antidepressant "failures," atypical or mixed features. Antidepressant monotherapy in unrecognized bipolar disorder can trigger manic switch and cycle acceleration.
Medical Mimics
First episode, late onset, atypical features, or treatment non-response should prompt medical workup. Minimum: TSH for every first episode. Consider sleep study, CBC, B12, folate, vitamin D. Review medication list for depressogenic agents (corticosteroids, beta-blockers, interferons).
Functional Collapse
Inability to work, care for self or dependents, or maintain basic safety. Severe neurovegetative changes (not eating, not sleeping, psychomotor retardation). May warrant higher level of care assessment.
Related Medications
Medications commonly used in the treatment of major depressive disorder:
Practice With Related Cases
Practice identifying and managing major depressive disorder through these educational case studies:
References & Further Reading
This educational summary synthesizes information from standard clinical references for learning purposes. It is not a substitute for primary sources. Always verify against current clinical guidelines before applying any content in practice.
- American Psychiatric Association practice guidelines and current diagnostic standards (2022)
- APA Practice Guideline for the Treatment of Major Depressive Disorder (3rd Edition, 2010; guideline watch updates)
Test your knowledge
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