Birth characteristics and schizotypy: Evidence of a potential “second hit”

Season of birth and subclinical psychosis: Systematic review and meta-analysis of new and existing data

“…New data) and three other publications indicated no statistically significant association (Breetvelt et al, 2010;Cohen & Najolia, 2011;Reid & Zborowski, 2006). From the later set of null studies, Reid et al (2006) reported statistically significant results for the spring group (compared with all other births).…”

“…The other five studies reported on adult populations. Whereas the new data and two other studies (Cohen et al, 2011;Hori et al, 2012) analyze relationships between schizotypal personality traits with the SPQ, reports by Bolinskey et al (2013) and Reid et al (2006) were based on the Chapmann Psychosis Proneness Scales (CPPS) (Chapman, Chapman, & Raulin, 1978;Eckblad & Chapman, 1983;Eckblad, Chapman, Chapman, & Mishlove, 1982). Hence, these five studies were first divided into two subsets (schizotypal personality or psychosis proneness) and later combined into a larger 5-study block for comparison.…”

Season of birth and population schizotypy: Results from a large sample of the adult general population

“…Screening a large number of university students and comparing individuals high in scores of schizotypal personality disorder to the rest of the sample, Cohen and Najolia (2011) found no direct evidence of differences in season of birth between these two groups. Only persons scoring high in schizotypal personality disorder who also reported a clinical history of schizophrenia were significantly more likely born in winter.…”

“…One study as well as a recent meta-analysis including new primary data indicated that there may be no seasonal effect on schizotypy in the adult population (Cohen and Najolia, 2011;Córdova-Palomera et al, 2015). Screening a large number of university students and comparing individuals high in scores of schizotypal personality disorder to the rest of the sample, Cohen and Najolia (2011) found no direct evidence of differences in season of birth between these two groups.…”

Category fluency in psychometric schizotypy: how altering emotional valence and cognitive load affects performance

“…The SPQ-BR was developed from the Schizotypy Personality Questionnaire (SPQ; Raine, 1991), has a similar three factor structure (positive, negative, disorganized), and has demonstrated strong . In previous studies, individuals with elevations on psychometric questionnaires-like the SPQ-BR-have exhibited increased risk for psychotic and other psychiatric disorders (Cohen & Najolia, 2011;Gooding, Tallent, & Matts, 2005;Kwapil, Miller, Zinser, Chapman, & Chapman, 1997). participants were instructed to press 'S' if the shape was the same as the previous shape or 'L' if the shape was not the same as the previous shape.…”