Impact of anxiety and depression on medication adherence among patients diagnosed with asthma and stroke

Psychological distress is common in patients with chronic medical conditions. However, it remains unclear whether the mechanisms explain the interaction between psychological distress and risk or protective factors for medication adherence are the same or different among individuals diagnosed with asthma and those who have survived a stroke. This study investigated the impact of anxiety and depression on medication adherence in patients with asthma and stroke. A total of 117 patients with asthma and 200 patients with stroke completed a one-time survey, including the shortened Medication Adherence Report Scale, Hospital Anxiety and Depression Scale, Beliefs about Medicines Questionnaire, and Trust in Physician Scale. Hierarchical linear regression analyses and moderation analyses were conducted to examine the role of anxiety and depression in medication adherence. Anxiety significantly predicted medication adherence after controlling for depression in both patients with asthma (p < 0.001) and stroke (p = 0.026). Among the four beliefs about medication, beliefs of necessity (p = 0.010) and harm (p = 0.021) significantly predicted medication adherence in the sample of stroke patients, but not asthma patients. Furthermore, in patients with asthma, the relationship between trust in physician and medication adherence was moderated by anxiety (p = 0.001), but not by depression (p = 0.412). However, this moderation relationship was not observed in the sample of stroke patients. Anxiety, but not depression, significantly predicted medication adherence in both patients with asthma and stroke. Further, trust in physician predicted medication adherence among more anxious patients with asthma, suggesting the importance to ensure adequate support and assurance from physicians. Therefore, intervention programs for improvement of medication adherence should be developed and delivered in a manner specific to the chronic condition.