Retrospective cohort study of ambulatory care pharmacist interventions’ impact on incidence of therapeutic response in anxiety and depression

Introduction

Ambulatory care pharmacists continue to expand their involvement in the management of various disease states across the United States, including anxiety and depression. There is limited literature assessing the clinical impact of these practice advances implemented by pharmacists who do not carry psychiatric training (i.e., psychiatric board certification or mental health training) within primary care.

Methods

This was a retrospective, multicenter, cohort study of adult patients who had at least one documented visit between February 2020 and August 2023 with an ambulatory care pharmacist who did not carry additional psychiatric training to comanage their diagnosis of depression and/or anxiety. The primary outcome was the achievement of a therapeutic response (a reduction of 50% or greater in Patient Health Questionnaire 9-item depression scale [PHQ-9] and/or the Generalized Anxiety Disorder 7-item scale [GAD-7] scores). Secondary outcomes included the change in PHQ-9 and/or GAD-7 scores, incidence of remission, predictors of therapeutic response, pharmacist intervention subtypes, and percentage use of pharmacogenomics.

Results

Therapeutic response for PHQ-9 was achieved for 60 (48.4%) of 124 patients included after utilization of an ambulatory care pharmacist without additional psychiatric training embedded in primary care. While two-thirds of patients had comorbid anxiety, 43 (57.4%) could not be evaluated for clinical improvement as they did not have available GAD-7 scores for analysis. Available PHQ-9 and GAD-7 scores had median score reductions of 5 (−11,0) and 4.5 (−7.75, 3.5), respectively, at approximately 6 months (p < 0.001 and p = 0.023). Patients had a median number of 4 (2, 5) visits with a pharmacist and a median number of 2 (1, 3) interventions.

Conclusions

Ambulatory care pharmacists, regardless of additional psychiatric training, can help patients achieve a therapeutic response for depression and anxiety as well as significantly improve PHQ-9 and GAD-7 scores. Additional education on the importance of GAD-7 monitoring is warranted given its lack of routine collection and evaluation among patients presenting with comorbid depression and anxiety.