Bullying victimization (BV) is a risk factor for the development of psychotic experiences and psychotic disorders1, 2. We used data from TRAILS (TRacking Adolescents' Individual Lives Survey), a longitudinal cohort study of Dutch pre‐adolescents3, to study the relationship between polygenic risk score for schizophrenia (SCZ‐PRS) and BV, and the possible role of BV in mediating the effect of genetic risk for schizophrenia on the development of psychotic symptoms later in life. Three assessment waves of TRAILS – T1 (10‐12.5 years old), T2 (12.4‐14.6 years old) and T3 (14.8‐18.3 years old) – were considered. We assessed IQ using the Wechsler Intelligence Scale for Children (WISC), administered at T1; BV through peer nomination scores at T1 and T2; social competence at T1 using the Revised Class Play (RCP); teacher‐reported relational aggression by Likert scales at T2; and lifetime psychotic experiences using the Community Assessment of Psychic Experiences Scale at T3. We imputed TRAILS genotypic data using Sanger Imputation Service (1000 Genomes Project Phase 3 reference GRCh37/hg19). We excluded siblings and pupils on special education, checked genotype quality, derived genomic components to control for ancestry, and computed individual polygenic risk scores (PRS) for schizophrenia, attention‐deficit/hyperactivity disorder, autism, bipolar disorder, major depression, and obsessive‐compulsive disorder, using standard procedures4. We focused on PRS‐6 (including variants with association p‐value <0.05), a measure of genetic risk yielding the highest prediction accuracy for schizophrenia5. We divided the sample into PRS tertiles, reflecting low, medium and high risk. We explored whether BV was uniformly distributed across ...
Language: en
LA - en SN - 1723-8617 UR - http://dx.doi.org/10.1002/wps.20685 ID - ref1 ER -