Background Urbanicity, immigration and winter-birth are stable epidemiological risk factors for schizophrenia, but their relationship to schizotypy is unknown. This is a first examination of the association of these epidemiological risk factors with positive schizotypy, in nonclinical adolescents, controlling for a range of potential and known confounders. Methods We collected socio-demographics, life-style, family and school circumstances, positive schizotypy dimensions and other personality traits from 445 high school pupils (192 males, 158 immigrants) from 9 municipalities in Athens and Heraklion, Greece, which covered a range of host population and migrant densities. Using multivariate hierarchical linear regressions models, we estimated the association of schizotypy dimensions with: (1) demographics of a priori interest (winter-birth, immigrant status, urban characteristics), including family financial and mental health status; (2) factors resulting from principal component analysis (PCA) of the demographic and personal data; (3) factors resulting from PCA of the personality questionnaires. Results Adolescent women scored higher on schizotypy than men. High anxiety/neuroticism was the most consistent and significant predictor of all schizotypy dimensions in both sexes. In the fully adjusted models, urbanicity predicted magical thinking and unusual experiences in women, while winter-birth and immigration predicted paranoid ideation and unusual experiences respectively in men. Conclusions These results support the continuum hypothesis and offer potential insights in the nature of risk conferred by winter-birth, urbanicity and immigration and the nature of important sex differences. Controlling for a wide range of potential confounding factors increases the robustness of these results and confidence that these were not spurious associations. © 2017 Elsevier Masson SAS

risk factors schizophrenia personality Environment Adolescence

personal experience urban population immigrant lifestyle anxiety disorder Magic reward population density predictive value mental health human paranoia immigration sex difference statistics and numerical data schizotypal personality disorder controlled study priority journal health status Seasons Urbanization academic achievement mental disease predictor variable Surveys and Questionnaires Young Adult cross-sectional study migrant quality of life season Adolescent Humans male Emigrants and Immigrants female personality test State Trait Anxiety Inventory risk factor Risk Factors Greece questionnaire Psychometrics Eysenck Personality Questionnaire child psychiatry Article seasonal variation psychometry Schizotypal Traits Questionnaire Behavioral Inhibition Behavioral Activation System questionnaire schizophrenia assessment major clinical study adult behavior disorder assessment winter birth family relation Temperament and Character Inventory drug use confounding variable Personality Linear Models family history principal component analysis childbirth family income high school student statistical model personality assessment neurosis