Bipolar Disorder

Introduction

Bipolar disorder is characterized by recurrent episodes of elevated or irritable mood and depression, accompanied by changes in sleep and energy and associated with cognitive, physical and behavioural symptoms.

Bipolar I disorder is characterized by at least 1 episode of mania, and usually episodes of depression and/or hypomania.
Bipolar II disorder is characterized by a history of major depressive episodes and hypomanic episodes only, without episodes of mania.

Bipolar disorder has a strong genetic basis and a peak onset in young people.

Management

Consider mood stabilizers (e.g. lithium or valproate) and second-generation antipsychotics (e.g. quetiapine, lurasidone, aripiprazole, olanzapine, risperidone) for the primary treatment of bipolar disorder.

For maintenance treatment of bipolar disorder, aim for the highest tolerable lithium plasma level in the range of 0.6-0.8 mmol/L.

Reduce to 0.4-0.6 mmol/L in case of good response but poor tolerance, or
Increase to 0.8-1.0 mmol/L in case of insufficient response and good tolerance.

Because of lithium's relatively narrow therapeutic index, toxic effects reliably occur at levels >1.5 mmol/L and usually consist of gastrointestinal symptoms (increasing anorexia, nausea and diarrhoea) and CNS effects (muscle weakness, drowsiness, confusion, ataxia, coarse tremor and muscle twitching).
Valproate is strictly contraindicated in women of child-bearing potential, unless no other effective alternative exists.

Consider electroconvulsive therapy for severe manic or depressive episodes.

Summary

Lithium is the best-performing mood stabiliser for bipolar disorder in practice with a prophylactic effectiveness similar to long-acting antipsychotics.

In the event of relapse, an urgent plasma lithium level should be obtained to indicate the level of compliance with lithium therapy and inform possible dose adjustment.

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