Schizotypy is regarded as a subthreshold expression or precursor of schizophrenia spectrum psychosis.

Schizotypal personality disorder is a risk factor of the ‘genetic risk and functional decline’ criterion of the ultra-high risk (UHR) criteria for psychosis; and its positive features are part of attenuated psychotic symptoms (APS) of the UHR criteria. Furthermore, schizotypy as assessed with the Wisconsin Scales of Schizophrenia Proneness (WSSP) 'Perceptual Aberration”, 'Magical Ideation”, and 'Social Anhedonia” but not 'Physical Anhedonia” was predictive of psychosis in the community.

Thus, we examined the psychosis-predictive value of the for WSSP in 128 patients seeking help at an early detection service (23+/-7 yrs; 56% male; 81% at-risk for UHR and/or basic symptom criteria) with a median follow-up of 24 (1-101) months by Cox regression.

Within 48 months; 36 patients converted to psychosis. Unexpectedly, none of the four WSSP was a significant predictor of conversion. This negative finding was replicated when the positive (Perceptual Aberration and Magical Ideation) and negative (both Anhedonia scales) dimension were examined. Thus, although schizotypy scales might be able to identify a more extreme range of the psychotic continuum in the community, they lack the ability to further separate ‘true’ from ‘false’ risk cases in a clinical sample already representing this more extreme range of the psychotic continuum.

This indicates that WSSP might be useful rather as an initial screening for persons potentially at-risk for current criteria in the community than as additional predictors in already identified risk patients.