Trends in the treatment of bipolar disorder by outpatient psychiatrists.

OBJECTIVE

This study examined recent changes in the prescribing patterns for medications to treat bipolar disorder in office-based psychiatric practice.

METHOD

The authors analyzed physician-reported data from the National Ambulatory Medical Care Survey for 1992-1995 and 1996-1999, focusing on physicians specializing in psychiatry. Demographic, clinical, and medication prescription characteristics of patients' visits were compared to identify changes between the periods. Logistic regression models were used to identify predictors of medication prescription, with adjustment for the presence of other covariates.

RESULTS

In both survey periods, over one-third of the total psychiatrist visits by patients with bipolar disorder did not include prescription of a mood stabilizer. There was a decrease in the use of lithium over time, accompanied by an increase in the use of valproic acid. Antipsychotic medication was prescribed more frequently for the bipolar manic and mixed subtypes, and there was a secular increase in the use of the newer antipsychotics. During each time period, prescription of antidepressants was common, often in the absence of a mood stabilizer.

CONCLUSIONS

Despite important advances in the range of mood stabilizers available, the pharmacological treatment of bipolar disorder continues to be an area with substantial opportunity for quality improvement.