This common type of depression predicts bipolar II disorder and response to lithium and MAOIs
STUDY: Ingrosso G and Cleare AJ, Front Psychiatry 2026
STUDY TYPE: Narrative review
FUNDING: NIHR Maudsley Biomedical Research Centre
Background
Atypical depression was first described in the 1950s as a way of recognizing patients who responded better to MAOI than tricyclic antidepressants. Although common, it was called “atypical” because it was rare in hospitalized patients. The first report described “somewhat atypical depressive states, sometimes resembling anxiety hysteria with secondary depression.”
DSM-5-TR defines it by mood reactivity with at least two of:
- Hypersomnia
- Overeating or weight gain
- Leaden paralysis (“do you feel like your arms are legs are pulled down by heavy weights?”)
- Rejection sensitivity
This review from King’s College London updates the evidence.
Summary
- 15% to 40% of patients with unipolar depression have atypical features
- More often women, with earlier onset and a more chronic course
- The higher rates in women level off after menopause
- Atypical depression is linked to higher rates of bipolar II disorder, as well as social anxiety, panic disorder, binge eating, bulimia, childhood abuse, and personality disorders
Several studies found that mood reactivity, the core DSM criterion, fails to separate atypical depression from other subtypes. Oversleeping and overeating alone identify the same patients, with the similar links to bipolar II and response to MAOIs.
Biology
Compared with melancholic depression, atypical depression has lower cortisol, higher inflammatory markers, and more obesity, insulin resistance, and metabolic syndrome, earning it the new name “immunometabolic depression.”
Links to Bipolar
- In one sample of 86 patients, 33% met full criteria for bipolar II and 72% met broader bipolar spectrum criteria.
- Nearly 60% had cyclothymic or hyperthymic temperaments.
Treatment
- MAOIs: Phenelzine has the most evidence. In chronic atypical depression, 6-month relapse was 23% on phenelzine vs 41% on imipramine, and 87% after stopping phenelzine.
- SSRIs: Fluoxetine, sertraline, and escitalopram work, though one large genetic study found patients reported poorer response to SSRIs and SNRIs.
- Lithium augmentation: Patients with atypical features were twice as likely to respond (aHR 2.20).
- ECT: Atypical features nearly tripled the odds of remission.
- Aripiprazole augmentation helped, while bupropion augmentation did not (Dr. Aiken’s note: bupropion augmentation failed in the only large trial of general depression, but obesity does predict response to bupropion augmentation).
Practice Implications
- Ask about atypical features. When positive, consider bipolar II, lithium augmentation, and MAOIs (but caution with these in bipolar).
- Check metabolic health in atypical depression.
—Chris Aiken, MD
Director, Psych Partners
Editor in Chief, Carlat Psychiatry Report
