Efficacy of pharmacotherapy in bipolar disorder: a report by the WPA section on pharmacopsychiatry
OBJECTIVE Bipolar disorders are prevalent major illnesses with high rates of morbidity, comorbidity, disability, and mortality. A growing number of psychotropic drugs are used to treat bipolar disorder, often off-label and in untested, complex combinations. METHODS To quantify utilization rates for psychotropic drug classes, this study used the 2002-2003 U.S. national MarketScan research databases to identify 7,760 persons with ICD-9 bipolar disorder subtypes. Survival analysis was used to estimate times until initial monotherapies were augmented, changed, or discontinued. RESULTS The most commonly prescribed first drug class was antidepressants (50% of patients), followed by mood stabilizers (25%: anticonvulsants, 17%, and lithium, 8%), sedatives (15%), and antipsychotics (11%). At study midpoint only 44% of patients were receiving monotherapy. Those receiving monotherapy were ranked by initial drug prescribed and percentage of patients (bipolar I and bipolar II): antidepressants (55% and 65%), lithium (51% and 41%), antipsychotics (32% and 31%), anticonvulsants (28% and 29%), and sedatives (28%, 25%). Median time to adding another psychotropic was 2.5-times less than median time to changing the initial treatment (16.4 compared with 40.9 weeks), and stopping was rare. Median weeks until therapy was changed in any way for 25% of patients was as follows: lithium, 29 weeks; antidepressants, 13; anticonvulsants, 13; antipsychotics, 13; and sedatives, 9. CONCLUSIONS Antidepressants were the first-choice agent twice as often as mood stabilizers. Lithium was sustained longer than monotherapy with other mood stabilizers. Time to augmentation was much shorter than time to change or discontinuation.