OBJECTIVES: Many patients with schizophrenia and bipolar disorder have impaired insight and low medication adherence. The aim of this post-hoc analysis is to explore the relationship between insight and medication adherence and their impact on the outcomes of patients with schizophrenia or bipolar disorder.
METHODS: We included 903 patients with schizophrenia or bipolar disorder who participated in an observational study conducted in Europe on the outcomes of patients treated with two oral formulations of olanzapine over a 1-year period. Evaluations included Clinical Global Impression (CGI), Global Assessment of Functioning (GAF), insight (Scale to Assess Unawareness of Mental Disorder, SUMD), non-adherence (Medication Adherence Rating Scale, MARS), and therapeutic alliance (Working Alliance Inventory, WAI). Correlations between variables were assessed by Spearman Correlation Coefficient (SCC). A path analysis was used to understand the relationship between insight, adherence, therapeutic alliance and outcomes.
RESULTS: 67.8% of patients had schizophrenia. GAF score was higher in bipolar vs schizophrenia patients (mean (SD) 58.4 (15.6) vs 51.9 (15.7), p<0.001). Medication adherence was also higher in bipolar patients (mean MARS score (SD) 6.5 (2.8) vs 5.8 (2.7); p< 0.001). Patients with schizophrenia had lower insight (i.e. SUMD item 1, unawareness of mental disorder, mean (SD) of 2.5 (1.3) in schizophrenia vs 1.9 (1.2) in bipolar, p<0.001). Better insight was associated with higher adherence (SCC, ranging from 0.39 to 0.49 for the three SUMD general items, p<0.0001 in all cases) Higher insight was related to a stronger therapeutic alliance (SCC ranging from 0.38 to 0.48, p< 0.0001). The path analysis revealed a positive impact of insight on adherence and alliance and that stronger alliance was related to lower clinical severity (lower CGI score).
CONCLUSIONS: Insight and adherence were found to be closely related. Insight impacts on the therapeutic alliance with mental health professionals. These factors are associated to treatment outcomes.
