Bipolar disorder

The evidence of a clear genetic predisposition to bipolar illness has led to important efforts in gene discovery, and several linkage studies have produced similar results. However, these results are not sufficiently robust to be used in genetic counseling. New drugs, such as valproic acid and lamotrigine, are effective. These drugs are useful alternatives for patients in whom adverse effects occur with lithium or in whom the response to lithium is inadequate, but no drug seems more effective than lithium for the majority of patients with bipolar illness. Although the search for evidence of abnormalities in neurochemical and neuroimaging studies remains promising, diagnostic markers that would have clinical relevance have still to be discovered. A new diagnostic tendency to view milder conditions that include mood swings as variants of bipolar illness may lead to more effective treatment for some affected patients, often with lithium or valproate, but the use of these agents in mild variants of the disorder remains unsupported by strong biologic or clinical data. For this reason, clinicians should be careful to avoid misdiagnosing psychological or social phenomena as bipolar illness. Increasing evidence for the efficacy of new atypical antipsychotic drugs in the treatment of and prophylaxis against bipolar illness has provided a major treatment alternative that may, in the future, blur the diagnostic and therapeutic boundaries between bipolar illness and schizophrenia. However, the emerging adverse effects of these new compounds cannot be ignored.