Validation of a novel Psychosis-Implicit Association Test (P-IAT) as a diagnostic support tool.

Overview

Despite significant advances in early-intervention services for psychosis, delays in identifying patients continue to impede the delivery of prompt and effective treatments. We sought to develop and preliminarily validate a self-administered psychosis implicit association task (P-IAT) as a screening and diagnostic support tool for identifying individuals with psychotic illness in community settings. The P-IAT is a response latency task, designed to measure the extent to which individuals implicitly associate psychosis-related terms with the "self." The P-IAT was administered to 57 participants across 3 groups: healthy controls (N=19), inpatients hospitalized with active psychosis (N=19), and outpatients with psychotic disorders (N=19). Mean D-scores (the output of the task) differed significantly between the illness groups and healthy controls (Mann-Whitney U=138, p<.001). A receiver operating curve was plotted to assess the performance of D-scores in predicting a psychosis diagnosis, yielding an area under the curve of 0.81. When participant D-scores exceeded -0.24, the test achieved a specificity of 100% (sensitivity: 47%), with all 18 participants scoring above this threshold belonging to the illness groups. The discriminant performance of the P-IAT suggests its potential to augment existing screening instruments and inform referral decision making, particularly in settings with limited access to specialist providers.