Clinical correlates of medication adherence in individuals with bipolar disorder and comorbid hypertension

Abstract

Objective Individuals with bipolar disorder (BD) have high rates of suboptimal medication adherence, medical illness, and premature mortality, largely from cardiovascular causes. This analysis examined the association between adherence to antihypertensive and BD medications and clinical symptoms in patients with BD and comorbid hypertension (HTN) from an ongoing trial to optimize adherence. Method Inclusion criteria were a BD diagnosis, treatment with antihypertensives, adherence challenges, and poorly controlled HTN. Adherence was measured via self-report using the Tablets Routine Questionnaire and using eCAP, an electronic pillcap which captures openings. Average systolic blood pressure (SBP) was calculated from 12 readings over 1 week. The Montgomery-Asberg Depression Rating Scale (MADRS) and the Brief Psychiatric Rating Scale (BPRS) assessed BD symptoms. Results A total of 83 participants with BD and HTN were included. Adherence to BD and antihypertensive medications were positively correlated. eCAP openings showed more missed doses than self-reported antihypertensive adherence. BD medication adherence was positively correlated with BPRS at baseline; antihypertensive adherence was negatively correlated with SBP at screening. Antihypertensive adherence improved and SBP decreased between screening and baseline. Conclusions Adherence levels fluctuated over time and differed based on measurement method in people with comorbid BD and HTN. Self-reported BD adherence was positively related to global psychiatric symptoms and antihypertensive adherence was related to better SBP control. Monitoring both medication and blood pressure led to change in self-reported adherence. BD symptom severity may indicate poor adherence in patients with BD and should be considered in treatment planning.