OBJECTIVE: Assess recent pharmacologic treatment patterns for patients with bipolar disorder. METHODS: A large claims database of insured individuals from October 1998 to September 2002 was analyzed to identify patients diagnosed with bipolar disorder (ICD9-CM: 296.4x - 296.8x). Treatment regimens were examined for six-classes of psychotropics (antidepressants, mood-stabilizers, atypical and typical antipsychotics, anxiolytics and hypnotics) during the year post-diagnosis. Differences in medication use among sub-types of bipolar were compared. RESULTS: Of 6373 patients (56.4% female, mean age 49.2 years), 19.4% were depressed, 14.2% manic, 21.2% mixed, and 45.1% other episodes; 9.1% didn't receive psychotropic treatment. Among treated patients, 66.0% received antidepressants, 64.0% mood-stabilizers, 48.2% anxiolytics, and 42.1% atypical antipsychotics. Valproate (40.3%) and olanzapine (22.0%) were top two most commonly prescribed psychotropics. Only 22.7% received single-class therapy, 44.2% received = 3 classes and 19.8% received = 5 classes of psychotropics. Among depressed patients, 76.7% received antidepressants, 59.2% received mood-stabilizers and 39.9% received atypical antipsychotics versus 45.4%, 71.2% and 54.4% in manic patients, respectively. Surprisingly, 52.3% of depressed patients received anxiolytics - the highest percentage among all sub-types of bipolar patients. CONCLUSIONS: Pharmacotherapy for bipolar patients is complex. Nearly half of bipolar patients were treated with ³3 classes of psychotropics. Depressed patients were more likely to receive antidepressants and anxiolytics but less likely to receive mood-stabilizers.