Bipolar-I Patient Characteristics Associated with Differences in Antimanic Medication Prescribing

Objective: Second-generation antipsychotics offer more choice in antimanic pharmacologic treatment. Unclear though is whether they are expanding antimanic treatment, replacing mood stabilizers, or if/which patient characteristics influence prescribing choices. We studied the association between patient characteristics and patient-reported antimanic medication use upon entry in the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD).

Experimental Design: Observational study using STEP-BD baseline data from bipolar-I patients (N = 1,943) during years 2000-2004. Two logistic regression models (binomial and multinomial) were estimated to examine associations between patient characteristics and patient-reported drug use: 1) any antimanic medication (antipsychotic or mood stabilizer), and 2) mood stabilizer, antipsychotic monotherapy, or neither.

Principal Observations: At study entry over 80% of participants reported receiving at least one antimanic medication; 73% a mood stabilizer specifically. In general, there was no association between study year and the odds of entering on antimanic medication. Measures of psychiatric severity or complexity were more likely to be associated with differences in the drugs used; co-occurring medical conditions were not. Depressed states were associated with similar odds of antipsychotic monotherapy as elevated or mixed states. Compared to whites, blacks had greater odds of entering on antipsychotic monotherapy relative to a mood stabilizer.

Conclusions: Despite increasing pharmacotherapy options, we found no evidence that over time more patients received antimanic medication. Not all prescribing differences were consistent with the medical literature. Also, blacks were more likely to receive antipsychotic monotherapy, even after adjusting for clinical characteristics. Future research examining provider characteristics that influence prescribing is needed.