The primary purpose of this study is to evaluate the degree of impairment of decision-making capacity in schizophrenia patients compared to non-mentally-ill controls, as determined by the MacCAT-CR instrument.

We analyzed the results obtained from three databases: ISI Web of Science, Pubmed, and Scopus. Each database was scrutinized using the following keywords: “MacCAT-CR + schizophrenia”, “decision-making capacity + schizophrenia”, and “informed consent + schizophrenia.”

We included ten studies in the analysis. Even if schizophrenia patients have a significantly decreased decision-making competence compared to non-mentally-ill controls, they should be considered as competent unless very severe changes are identified during the clinical examination. Using enhanced informed consent techniques significantly decreased the difference between schizophrenia patients and non-mentally-ill controls (except for the reasoning dimension), and should be employed whenever the investigators want to include more severe patients in their clinical trials. Older age, an increased percentage of men gender or inpatient status tend to escalate the score difference of decision-making competence compared to non-mentally-ill subjects in various dimensions of the decision-making capacity. The main limitations of the study are: (1) a decreased number of studies included in the analysis is small (2) only three studies included data about enhanced ways of informing potential subjects.

The authors have not supplied their declaration of competing interest.