Bipolar I defined by presence of at least 1 manic episode +/- a hypomanic or depressive episode (may be separated by any length of time).

Bipolar II defined by presence of a hypomanic and a depressive episode (no history of manic episodes).

- Patient's mood and functioning usually normalize between episodes. - Use of antidepressants can destabilize mood.- High suicide risk.

Treatment: mood stabilizers (eg, lithium, valproic acid, carbamazepine, lamotrigine), atypical antipsychotics.

Cyclothymic disorder – milder form of bipolar disorder lasting ≥2 years, fluctuating between mild depressive and hypomanic symptoms.