Non-adherence to pharmacological treatment in schizophrenia and schizophrenia spectrum disorders: An updated systematic literature review

Background and objectives: The primary treatment for schizophrenia and schizophrenia-spectrum disorders is antipsychotic medication. One of the many public health challenges in mental illness, is to identify contributing factors to non-adherence to pharmacological treatment. The objective of this study was to perform an updated systematic review of risk factors for non-adherence to pharmacological treatment in schizophrenia in a European and American context. Methods: The study was a systematic literature review of studies that included at least two measurements of pharmacological adherence in adult schizophrenic patients. This was done to validate the measures of adherence adequately which is rarely done in previous adherence research. It was conducted using PRISMA guidelines surveying Pubmed and PsycINFO. Results: The definition of non-adherence varies greatly in eligible studies and the methodological approach to investigation of non-adherence is inconsistent. Thirteen studies fit the inclusion criteria and demonstrated several risk factors statistically influencing non-adherence rates. The most frequent risk factors identified for non-adherence were poor insight into or lack of awareness of illness, alcohol or drug abuse and unspecified younger age. Conclusions: The findings in this systematic literature review are consistent with previous reviews on non-adherence and schizophrenia. It stresses the methodological challenges in psychiatric adherence research and establishes the need for more systematic and rigorous study design and methods within this field. (c) 2017 Published by Elsevier Espana, S.L.U. on behalf of Asociacion Universitaria de Zaragoza para el Progreso de la Psiquiatria y la Salud Mental.