Assessing Refill Data Among Different Classes of Antidepressants

Geographically diverse studies with larger sample sizes need to be conducted to better understand antidepressant adherence and its barriers and facilitators in the veteran population. The exclusion of patients with previous trials of the prescribed antidepressant may have led to a possible selection bias favoring inclusion of younger patients. These patients may have a more limited period for assessment and treatment when compared with older patients, and thus may have had a smaller chance of previous exposure to the prescribed antidepressant. Neither MAOIs or TCAs were included in this study. No patients taking MAOIs were identified from the Antidepressant Nonadherence Report during the study period. Three patients on TCAs were chart reviewed, but excluded from the study because of prior use of the antidepressant or a non-mental health indication. Additionally, no newer antidepressants, including vortioxetine and vilazodone, were included, likely secondary to their nonformulary status at the VA.

Conclusion

As this study’s purpose was to improve the quality of care at our facility, we will discuss our findings with local MHPs to develop strategies to improve antidepressant adherence. While larger studies need to be conducted to confirm our findings, it is worthwhile to consider risk factors for low adherence such as SUD when prescribing antidepressant medications. Patients with SUD could be encouraged to enroll in our facility’s telephone nursing depression care management program for more frequent follow up and medication adherence counseling.

This study did not find a significant difference in 3-month adherence rates between SSRIs, SNRIs, bupropion, and mirtazapine. SUD was significantly more common in patients with low adherence than those categorized as adherent and may be a risk factor for low adherence based upon our findings and those of previous studies.