Association Between Symptom Severity and Medication Adherence in Adults with Bipolar Disorder Reporting Adherence Challenges

Abstract

Background: Given the importance of medication adherence among individuals with bipolar disorder (BD), this analysis from an ongoing randomized controlled trial (RCT) examined the relationship between BD symptoms, functioning and adherence in 69 poorly adherent adults with BD.

Method: Study inclusion criteria included being ≥ 18 years old with BD Type 1 or 2, difficulties with medication adherence and actively symptomatic as measured by Brief Psychiatric Rating Scale (BPRS) score ≥ 36, Young Mania Rating Scale (YMRS) > 8 or Montgomery Asberg Depression Rating Scale (MADRS) > 8. Adherence was measured in 2 ways: 1) the self-reported Tablets Routine Questionnaire (TRQ) and 2) electronic pill container monitoring (eCap pillbox). BD symptoms and functioning were measured with the MADRS, YMRS, Clinical Global Impressions Scale (CGI), and Global Assessment of Functioning (GAF). Only screening and baseline data were examined.

Results: Mean age was 42.32 (SD = 12.99) years, with 72.46% (n = 50) female and 43.48% (n = 30) non-white. Mean past 7-day percentage of days with missed BD medications using TRQ was 40.63% (SD = 32.61) and 30.30% (SD = 30.41) at screening and baseline, respectively. Baseline adherence using eCap was 42.16% (SD = 35.85) in those with available eCap data (n = 41). Worse adherence based on TRQ was significantly associated with higher MADRS (p = 0.04) and CGI (p = .03) but lower GAF (p = 0.02). eCAP measured adherence was not significantly associated with clinical variables.

Conclusion: While depression and functioning were approximate markers of adherence, reliance on patient self-report or BD symptom presentation may give an incomplete picture of medication-taking behaviors.

Keywords: bipolar disorder; depression; mania; manic depressive disorder; medication adherence.