Predictors of Beliefs About Medicines in Patients with Psychotic Disorders - A Longitudinal Observational Study in Mental Health Services.

PURPOSE: Patients' necessity beliefs and concerns about antipsychotic medication may influence medication adherence. This study aimed to identify factors predicting necessity beliefs and concerns about antipsychotic medication.

PATIENTS AND

METHODS

This longitudinal study included patients with psychotic disorders from 31 Norwegian specialist mental health care units at baseline (0 months; N=310) and 12 months (n=151), reflecting attrition. We investigated associations between patients' sociodemographic and clinical characteristics, their perceptions of medication support (MedSupport questionnaire), and their medication necessity beliefs and concerns (Beliefs about Medicines Questionnaire; BMQ) at baseline. We assessed change in BMQ subscales from baseline to 12 months and factors associated with the change. The data were analyzed using linear mixed-effects models.

RESULTS

At baseline, higher MedSupport scores were associated with higher BMQ-Necessity (β=0.18 (95% confidence interval (CI)=0.04 to 0.33)) and lower BMQ-Concerns (β=-0.29 (95% CI=-0.42 to -0.16)) subscales. Higher educational level and higher number of psychotropic medications were associated with higher BMQ-Necessity. Higher symptom load and medication side effects were associated with higher BMQ-Concerns. Patients' beliefs about their medications became more negative over time, ie BMQ-Necessity scores decreased (-0.35 (95% CI=-0.60 to -0.11)) and BMQ-Concerns increased (0.25 (95% CI=0.05 to 0.45)). Higher dose of psychotropic medications at baseline and female sex was associated with an increase in BMQ-Necessity. A higher number of antipsychotic medications was associated with an increase in BMQ-Concerns from baseline to 12 months.

CONCLUSION

Patients who experienced better medication support had significantly more positive medication beliefs at study start. Patients' views about their medications became significantly more negative over the one-year follow-up, highlighting the potential need for clinicians to provide follow-up support to address the doubts and concerns that might emerge over the course of treatment.