Determinants of medication compliance in schizophrenia: empirical and clinical findings.

Advances in psychopharmacology have produced medications with substantial efficacy in the treatment of positive and negative symptoms of schizophrenia and the prevention of relapse or symptom exacerbation after an acute episode. In the clinical setting, the individual patient's acceptance or rejection of prescribed pharmacological regimens is often the single greatest determinant of these treatments' effectiveness. For this reason, an understanding of factors that impede and promote patient collaboration with prescribed acute and maintenance treatment should inform both pharmacological and psychosocial treatment planning. We review the substantive literature on medication adherence in schizophrenia and describe a modified health belief model within which empirical findings can be understood. In addition to factors intrinsic to schizophrenia psychopathology, medication-related factors, available social support, substance abuse comorbidity, and the quality of the therapeutic alliance each affect adherence and offer potential points of intervention to improve the likelihood of collaboration. Because noncompliance as a clinical problem is multidetermined, an individualized approach to assessment and treatment, which is often best developed in the context of an ongoing physician-patient relationship, is optimal. The differential diagnosis of noncompliance should lead to interventions that target specific causal factors thought to be operative in the individual patient.