A Cross-Sectional Study of Patients' Perspectives on Adherence to Antipsychotic Medication: Depot Versus Oral

Background: Antipsychotic depot medications improve medication adherence by reducing covert nonadherence, but some clinicians believe that they are unacceptable to patients. This cross-sectional study investigated patients’ perspectives on factors influencing adherence to antipsychotics, from both those taking depots and those taking tablets in ongoing voluntary outpatient care. The study is novel in also encompassing such factors as injection phobia and perceived coercion regarding medication in relation to self-reported adherence.

Method: Seventy-three patients with schizophrenia/schizoaffective disorder (ICD-10 criteria) completed structured clinical interviews that included the Rating of Medication Influences (ROMI) scale as well as instruments that assessed patients’ functioning, psychopathology, insight, extrapyramidal symptoms, quality of life, needle anxiety, experience of coercion, and beliefs about medication.

Results: Participants taking depot (vs. oral) medication had higher ROMI noncompliance mean scores (15.7 vs. 14.4, p = .019). Predictive factors for influences on noncompliance included certain beliefs regarding medication (concern and overuse) but not extrapyramidal symptoms. There were no differences between the 2 formulation groups on the ROMI compliance subscale. Further predictive factors associated with influences on compliance included perceived necessity.

Conclusions: Previously, side effects were considered to be a reason for nonadherence to depot more than for oral medications, but our findings do not support this. Rather, beliefs and attitudes are more important than side effects in predicting self-reported adherence and influencing factors thereof. Prescribing a depot medication to enhance relapse prevention will not in itself ensure adherence and therefore must also be accompanied by discussion regarding adherence and associated personal benefits.