Bipolar disorder

Bipolar disorder (BD) is characterized by the episodic disturbance of mood into depression or elation. Bipolar I disorder (BD-I) is defined by mania, bipolar II disorder (BD-II) by major depression and hypomania. BD is heritable; many gene variants of small effect contribute to risk. Anxiety co-morbidity is common. The management of BD usually requires long-term medical treatment, and psycho-education is also key to management. Severe manic episodes, with or without mixed features, should be treated by an oral dopamine receptor antagonist/partial agonist. The treatment of bipolar depression is currently controversial. For an early treatment effect, quetiapine, lurasidone or olanzapine can be useful. Lamotrigine is underused. An antidepressant is not recommended as monotherapy for patients with BD but can be given with additional treatment to protect them from manic relapse. Relative or even marked treatment resistance can occur in depressed bipolar patients. The burden and pattern of illness should dictate the treatment choice and combination. If it is predominantly mania, the most antimanic agents (e.g. lithium, valproate, a dopamine receptor antagonist/partial agonist) are combined; for predominantly depressive BD, lamotrigine, quetiapine, lurasidone or olanzapine can be more appropriate. Long-term use of antidepressants can be justified if patients relapse on their discontinuation.