Co-occurrence of anxiety and bipolar disorders: clinical and therapeutic overview.

BACKGROUND: Anxiety commonly co-occurs with bipolar disorders (BDs), but the significance of such "co-morbidity" remains to be clarified and its optimal treatment adequately defined.
METHODS: We reviewed epidemiological, clinical, and treatment studies of the co-occurrence of BD and anxiety disorder through electronic searching of Pubmed/MEDLINE and EMBASE databases.
RESULTS: Nearly half of BD patients meet diagnostic criteria for an anxiety disorder at some time, and anxiety is associated with poor treatment responses, substance abuse, and disability. Reported rates of specific anxiety disorders with BD rank: panic ≥ phobias ≥ generalized anxiety ≥ posttraumatic stress ≥ obsessive-compulsive disorders. Their prevalence appears to be greater among women than men, but similar in types I and II BD. Anxiety may be more likely in depressive phases of BD, but relationships of anxiety phenomena to particular phases of BD, and their temporal distributions require clarification. Adequate treatment trials for anxiety syndromes in BD patients remain rare, and the impact on anxiety of treatments aimed at mood stabilization is not clear. Benzodiazepines are sometimes given empirically; antidepressants are employed cautiously to limit risks of mood switching and emotional destabilization; lamotrigine, valproate, and second-generation antipsychotics may be useful and relatively safe.
CONCLUSIONS: Anxiety symptoms and syndromes co-occur commonly in patients with BD, but "co-morbid" phenomena may be part of the BD phenotype rather than separate illnesses.