Pharmacological management of bipolar affective disorder

Lithium is the ‘gold standard’ of the many drug treatments used in bipolar disorder. It has efficacy in the treatment of mania, prophylaxis against manic relapses, and, to a lesser extent, prophylaxis against depressive relapses. It decreases suicidal risk. Blood monitoring of lithium is essential. In addition to side effects, problems include rebound mania on abrupt cessation of lithium and teratogenetic risks. Carbamazepine, valproate, and lamotrigine are anticonvulsants with an evidence base in bipolar disorder. Carbamazepine is anti-manic, but is poorly tolerated and associated with many pharmacokinetic interactions. Valproate is also anti-manic and is prophylactic, especially against mania, but its antidepressant effects in bipolar disorder are unclear. It is associated with many problems when used during pregnancy, and should be avoided in women of childbearing potential. Lamotrigine is not licensed for use in bipolar disorder in the UK, but has some evidence for effectiveness in bipolar depression and, more particularly, prophylaxis against depressive relapse. It must be introduced slowly to avoid dangerous skin reactions. Other anticonvulsants have no evidence supporting their use. Antipsychotics, including the atypicals, are effective in treating mania. Olanzapine and aripiprazole are also licensed for continuation treatment in acute responders. Quetiapine has evidence for effectiveness in both bipolar mania and bipolar depression. The efficacy of antidepressants in bipolar disorder is unclear. Tricyclic antidepressants and mono-amine oxidase inhibitors should probably be avoided, owing to a possible risk of switching to mania. In general, antidepressants should be used in conjunction with a mood stabilizer and for the shortest period necessary.