Differential results between self-report and interview-based ratings of risk symptoms of psychosis

AIM: Assessing potential risk of developing psychosis has gained growing attention in recent literature. The selection of suitable assessment methods is the central question for this research endeavour. Whereas prodromal detection instruments are mostly interview-based instruments, there are short screening instruments for self-report use. METHODS: Difference in psychosis risk scores was tested between self-report results and interview results, with risk symptoms of psychosis included in PROD screening instrument. Subjects were recruited by an early intervention team in Finland. RESULTS: There was a significant difference between psychosis risk scores based on self-report versus interview in a sample of adolescents (n=87; P<0.001). CONCLUSIONS: Results suggest that when using screening instruments, risk scores and risk status may vary by the method the information is collected. Checking self-report results by an additional interview is recommended for both clinical and scientific uses.