AimsThe approval of new drugs for bipolar disorder (BD) may have caused a shift in prescribing trends among patients with BD. The objective of the study was to describe prescribing trends amongst individuals with BD in Alberta, Canada.MethodsThis study used provincial administrative health data from Alberta, Canada. Individuals with at least one ICD-9 or ICD-10 code for BD were identified from three databases - Provider claims, Hospital Discharge Abstract Database and the Ambulatory Care Classification System. Within this cohort, we identified prevalent, new and combination use of commonly prescribed BD drugs through prescription information from the Pharmaceutical Information Network database.ResultsBetween April 1, 1994, and March 31, 2021, 136,628 individuals had at least 1 code of BD with 9,466,407 prescriptions dispensed between January 1, 2008 to March 31, 2021. New users of all drugs declined over time, especially from 2019 to 2021. Among all BD drugs, antidepressants were the most commonly prescribed in both prevalent and new users throughout the study period. Among recommended treatments for BD, quetiapine was one of the most prescribed drugs amongst prevalent users. An overall decline was noted in prescribing of lithium, divalproex and carbamazepine among prevalent and new users. Most individuals were prescribed a single drug for BD treatment. The most common combination therapy for prevalent users was an antidepressant with a second-generation antipsychotic (SGA).ConclusionsOverall, we uncovered a concerning trend in the prescribing patterns for BD treatment, with antidepressants and SGAs being prescribed frequently and a decline in prescribing of lithium and other mood stabilizers. This study emphasizes the need for initiatives promoting evidence-based guidelines and better alignment with best practices for managing BD in outpatient settings.