Increased Mortality in Parkinson’s Disease Linked to Low Antidepressant Adherence

A 4-year follow-up study is the first of its kind to show an inverse relationship between adherence to antidepressant medication and all-cause mortality in a large, population-based cohort of patients with Parkinson’s disease (PD). Findings from the retrospective analysis of medical data from the Clalit Health Service, the largest healthcare provider in Israel, were published in Parkinsonism and Related Disorders.

A total of 8553 patients with PD who purchased an antidepressant at least once between 2008 and 2011 were retrospectively followed over a 4-year period for all-cause mortality. Adherence, which was measured as a ratio between dispensed and prescribed durations, was classified as nonadherence (<20%, n=1566), poor adherence (20%-50%, n=1184), moderate adherence (50%-80%, n=1584), and good adherence (>80%, n=4219).

Unadjusted mortality rates were reported to be 20.4%, 25.1%, 23.4%, and 25.6% in those who were nonadherent, had poor adherence, had moderate adherence, and had good adherence to antidepressant therapy, respectively (P<.0001). Significantly increased adjusted mortality hazard ratios (HRs) were reported in the nonadherent (HR 1.43; 95% confidence interval [CI], 1.26-1.62) and poor adherence (HR 1.26; 95% CI, 1.1-1.44) arms compared with the good adherence arm. The adjusted HR for mortality among males was 1.49 (95% CI, 1.36-1.62) compared with females. Notably, those with a higher Charlson Comorbidity Index score (3-5+) had a greater risk for death than those with 0 to 2 comorbidities.

Based on these findings, neurologists, psychiatrists, and primary care physicians should be prioritizing the conscientious use of antidepressants among their patients with PD.

Reference

Shoval G, Stubbs B, Balicer RD, et al.  Low adherence to antidepressants is associated with increased mortality in Parkinson disease patients [published online August 1, 2017]. Parkinsonism Relat Disord. doi:10.1016/j.parkreldis.2017.07.032