Non-adherence with psychotropic medications in the general population

Abstract

Background: Non-adherence with medications is a general medical issue that has received much attention. However, the majority of studies have been on various clinical populations and the relevance of their results to the general population is unknown. In this study, we sought to determine the degree of non-adherence with antidepressants, antipsychotics, anxiolytics, mood stabilizers and sedative hypnotics, and to determine the reasons for non-adherence, in the general population of Canada.

Methods: We used data from the Canadian Community Health Survey: Mental Health and Well-Being (CCHS 1.2), conducted in 2002 (n = 36,984 adults), to produce population-based estimates of the degree of reported non-adherence with psychotropic medications and the reasons for non-adherence.

Results: The number of individuals taking psychotropic medications was 6,201. The prevalence of antipsychotic use over the last 12 months was estimated at 0.4% (95% CI 0.3-0.4). The corresponding estimates for sedative-hypnotics, anxiolytics, mood stabilizers and antidepressants were 10.2% (95% CI 9.8-10.7), 5.5% (95% CI 5.2-5.8), 1.1% (1.0-1.3) and 5.8% (95% CI 5.5-6.2), respectively. Non-adherence was estimated to be 34.6% (95% CI 25.5-44.9) for antipsychotics, 34.7% (95% CI 32.2-37.4) for sedative-hypnotics, 38.1% (95% CI 35.0-41.4) for anxiolytics, 44.9% (95% CI 38.1-51.9) for mood stabilizers and 45.9% (95% CI 43.1-48.7) for antidepressants. The degree of non-adherence decreased with age for antidepressants and anxiolytics. Forgetting was the main reported reason for non-adherence, but its degree varied with medication class. The proportion of respondents that reported forgetting as a reason was 36.3% (95% CI 32.0-40.8) for sedative-hypnotics, 46.7% (95% CI 41.3-52.2) for anxiolytics, 72.7% (95% CI 55.5-85.0) for antipsychotics, 74.2% (95% CI 64.0-82.3) for mood stabilizers and 74.5% (95% CI 70.7-77.9) for antidepressants. The degree of non-adherence and the frequency of forgetting were not associated with the level of interference by the associated condition with usual activities. The majority of these estimates were also not impacted by educational status, employment status, rural/urban residence, income or the presence of a comorbid physical condition.

Conclusion: A high frequency of non-adherence was found with all five classes of psychotropic medication. Both the frequency of reported non-adherence and the reasons reported for it differ according to the medication. However, the degree of non-adherence was not affected by the level of interference of the associated condition.