Collaboration in outpatient antipsychotic drug treatment: analysis of potentially influencing factors.

Knowledge of factors relevant for medication adherence and patient collaboration is still limited. Our study aims at exploring the contribution of a variety of factors to collaboration in outpatients with schizophrenia and schizoaffective disorder. We obtained self-rated and observer-rated data from 108 outpatients during an interview 6 months after hospital discharge. The compliance rating scale (CRS) classified 76% of the patients as collaborative. Factors related to the patient, illness, treatment, and social environment were analysed in two-step explorative correlation and regression analyses in order to determine their relative contribution to collaboration. Only trust in medication and lack of insight were associated with collaboration, and they accounted for 38% of the variance. Neither medication side effects nor neuropsychological functioning correlated with collaboration. The conceptualisation of medication adherence is complex, and there are a number of unresolved methodological problems. The data indicate that illness and treatment-related subjective attitudes may be more relevant than side effects, cognitive functioning or any sociodemographic variable.