# Prescribing Trends for Bipolar Disorder Drugs in Alberta, Canada Between 2008 and 2021: Tendances en matière de prescription de médicaments pour le trouble bipolaire en Alberta, au Canada, entre 2008 et 2021

## TL;DR

This study analyzed prescription trends for bipolar disorder in Alberta from 2008 to 2021, finding a decline in mood stabilizers and increased use of antidepressants and antipsychotics.

## Contribution

The study reveals a concerning shift in prescribing patterns for bipolar disorder, emphasizing the need for better adherence to evidence-based guidelines.

## Key findings

- New users of all bipolar disorder drugs declined over time, especially from 2019 to 2021.
- Antidepressants were the most commonly prescribed drugs, while lithium and other mood stabilizers saw a decline.
- The most common combination therapy was an antidepressant with a second-generation antipsychotic.

## Abstract

The 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.

This 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.

Between 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).

Overall, 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.

Prescribing Trends for Bipolar Disorder Drugs in Alberta, Canada Between 2008 to 2021

Plain Language Summary

This study examined prescribing trends for bipolar disorder (BD) in Alberta, Canada, using provincial health data. Among over 136,000 individuals with BD, prescription data from 2008 to 2021 showed a decline in new users of all BD medications, especially after 2019. Antidepressants were the most commonly prescribed drugs, followed by second-generation antipsychotics (SGAs) like quetiapine. In contrast, the use of mood stabilizers such as lithium, divalproex, and carbamazepine declined. Most patients received monotherapy, with the most common combination being an antidepressant plus an SGA. These trends highlight a shift away from traditional mood stabilizers and underscore the need for improved alignment of clinical practice and evidence-based BD treatment guidelines.