Features Indicative of Bipolar Disorders
| Bipolar | Unipolar | |
|---|---|---|
| Substance abuse | Very high | Moderate |
| Family history | Almost uniform | Sometimes |
| Seasonality | Common | Occasional |
| First episode <25 years | Very common | Sometimes |
| Postpartum illness | Very common | Sometimes |
| Psychotic features <35 years | Highly predictive | Uncommon |
| Atypical features | Common | Occasional |
| Rapid on/off pattern | Typical | Unusual |
| Recurrent major depressive episodes (>3) | Common | Unusual |
| Antidepressant-induced mania or hypomania | Predictive | Uncommon |
| Brief major depressive episodes (avg <3 months) | Suggestive | Unusual (episode duration usually >3 months) |
| Wearing off of antidepressant efficacy | Suggestive | Uncommon |
| Mixed depression (presence of hypomanic features within the depressive episode) | Predictive | Rare |
Data from refs. 7, 50, 54 (p. 114–9, 200–2), 51, 65, and 70.