Predictive Validity of Psychometrically Assessed Schizotypy for Psychopathology Dimensions and Functioning in an 8-Year Multiwave Study

Abstract

Background and Hypothesis: Although the psychometric high-risk method based on schizotypy has proven to be a highly cost-effective strategy for unraveling etiological factors for schizophrenia-spectrum disorders, there is a paucity of longitudinal studies with nonclinical populations. This study analyzed the predictive validity of positive and negative schizotypy in a longitudinal project (Barcelona Longitudinal Investigation of Schizotypy; BLISS) spanning a total of 7.8 years. Study Design: At Time 1 (T1), 547 college students completed the Wisconsin Schizotypy Scales. We re-assessed subsamples (oversampled for high schizotypy to ensure variability) at 4 re-assessments. This study reports psychopathology, psychological, and functional outcomes assessed with self-report and interview (CAARMS, Negative Symptom Manual, SCID-II Cluster A) measures at T4 (n = 89; 4.4 years after T1) and self-report measures at T5 (n = 169; 7.8 years after T1). T1 positive and negative schizotypy were entered simultaneously as predictors in linear regression models. Study Results: Positive schizotypy predicted positive symptoms at T4, whereas negative schizotypy predicted interview-rated negative symptoms and schizoid personality traits (even when controlling for mood and avoidant personality), and impaired social and global functioning. Both dimensions predicted suspiciousness, and schizotypal and paranoid personality traits, as well as low self-esteem and depression. Similarly, both dimensions predicted suspiciousness, depression, and poor social support at T5, whereas only positive schizotypy predicted low self-esteem, anxiety, and perceived stress. Conclusions: Both schizotypy dimensions consistently showed a meaningful pattern of hypothesized differential and overlapping predictions, which supports their validity as distinct dimensions and their predictive validity in nonclinical samples.