Nationwide and population-based prescription patterns in bipolar disorder.

OBJECTIVES: The aim of the present study was to describe prescription patterns and changes in these patterns over the last decade for patients diagnosed with bipolar disorder in mental healthcare, using population-based and nationwide data, and to relate the findings to recommendations from international guidelines.

METHODS: A population-based, nationwide study was carried out. It included register-based longitudinal data on all patients with a first-ever contact with mental healthcare with a diagnosis of mania/bipolar disorder from the entire Danish population, and all prescription data for this population during the decade from 2000 to 2011, inclusive.

RESULTS: A total of 3,205 patients were included in the study. Lithium was prescribed less, and antiepileptic and atypical antipsychotic agents were prescribed substantially more during the study period. Lithium went from being the first drug prescribed to being the last, and was replaced by atypical antipsychotic agents. Antiepileptic agents went from being the fourth to the second drug class prescribed, and the prescription of antidepressants was virtually unchanged, at a high level, during the decade (one-year value 40-60%). The prescription of lamotrigine and quetiapine increased substantially. Combination therapy increased for all drug combinations, except for lithium combined with antidepressants.

CONCLUSIONS: Major changes took place in drug prescriptions during the study period. The decrease in the use of lithium and the constant high use of antidepressants do not align with recommendations from international guidelines.