Verbal Mental Capacity and Medication Adherence in Psychiatric Outpatients: The Impact of Verbal Cognitive Reserve and Side Effects

Abstract

Objective: Medication adherence is a critical determinant of treatment outcomes in psychiatric disorders,
yet the underlying factors remain unclear. This study aimed to examine the role of verbal mental capacity
and clinical variables in predicting medication adherence among psychiatric outpatients.

Methods: A total of 67 patients (aged 18-60 years) were assessed using the Medication Adherence Rating
Scale (MARS), Beck Anxiety Inventory, Beck Depression Inventory, Liverpool University Neuroleptic Side
Effect Rating Scale (LUNSERS), and the Turkish version of the National Adult Reading Test (NART-TR).
Participants were categorized into good adherence (n=33) and poor adherence (n=34) groups based on
MARS scores. Comparative analyses between these groups, as well as correlation and multiple regression
analyses, were conducted.

Results: Patients with poor adherence had significantly higher anxiety, depression, side effect scores,
and NART-TR errors than patients with good adherence (P < .05). Correlation analysis revealed negative
associations between MARS scores and anxiety, depression, side effects, and NART-TR errors. Regression
analysis identified NART-TR errors (β=−.342, P=.009) and LUNSERS scores (β=−.512, P=.022) as
independent predictors of medication adherence.

Conclusion: Verbal mental capacity and medication side effects emerged as critical determinants of
adherence in psychiatric patients. Incorporating cognitive screening tools like NART-TR into routine
practice may help identify individuals at risk of nonadherence and guide tailored interventions.

Cite this article as: Bakay H, Karaagac M, Yaman NÖ, Gica S. Verbal mental capacity and medication adherence in
psychiatric outpatients: the impact of verbal cognitive reserve and side effects. Neuropsychiatr Invest. 2025, 63, 0045,
doi:10.5152/NeuropsychiatricInvest.2025.25045.