The objective of the study was to determine if DSM-5-defined attenuated psychosis syndrome (APS) could identify individuals with prodromal psychosis and predict conversion to schizophrenia spectrum disorders at a rate similar to that observed in previous studies that utilized structured interviews and specialized rating scales.
A retrospective review of patients’ medical records was used to identify individuals meeting diagnostic criteria for the APS, followed by further evaluation 2 to 3 years after the initial diagnosis, to determine if they converted to schizophrenia spectrum disorders. Results then were compared with previous studies.
Of our study population, 43.4% converted to schizophrenia or schizoaffective disorder 2 to 3 years after initial diagnosis of APS. Comparison at the 3-year mark indicated that there was no significant difference between our observed rates and previously published conversion rates (P = .066). Three covariates were found to increase significantly the rates of conversion when added to the APS criteria: Cannabis use (P = .048), lack of previous Axis I diagnosis (P = .005), and lack of previous treatment with psychotropic medications (P = .009).
APS accurately predicts conversion to full-scale schizophrenia spectrum disorders at a rate similar to that observed in previous studies using structured interviews and specialized rating scales.