Psychotic-like experiences and cognitive biases in adolescents: birthweight and sex moderating effects

Genetic and environmental factors are involved in the pathogenesis of psychosis. Obstetric complications such as low birth weight are among the more extensively studied environmental risk factors for schizophrenia and the psychosis spectrum. Cognitive biases, such as "jumping to conclusions" (JTC), are also linked to psychosis risk. The study aimed to examine the occurrence of cognitive biases and psychotic experiences in adolescents and explore whether birth weight is associated with these variables, moderated by sex.

A total of 240 adolescents (aged 14-15) from Sabadell, Spain, participated in the study, with 186 providing birthweight data. Psychotic experiences were assessed using the CAPE-P15 scale, while cognitive biases were measured with the Cognitive Biases Questionnaire for Psychosis. Multiple linear regression was conducted to explore associations between birth weight, sex, and psychometric outcomes.

Girls had lower birth weight than boys and exhibited higher rates of psychotic experiences and certain cognitive biases (e.g., catastrophizing, JTC). No significant associations were found between birth weight and total scores for psychotic experiences or cognitive biases. However, sex-specific patterns emerged in the relationship between birthweight and cognitive biases, with significant sex-by-birthweight interaction effects observed for JTC and dichotomous thinking.

The study suggests sex moderates the relationship between birthweight and cognitive biases. Our findings underscore the role of sex as a moderating factor in neurodevelopmental pathways leading to psychosis. Further research with larger samples is needed to explore these associations in greater depth.