It has not yet been determined if the commonly reported cannabis–psychosis association is limited to individuals with pre-existing genetic risk for psychotic disorders.

We examined whether the relationship between polygenic risk score for schizophrenia (PRS-Sz) and psychotic-like experiences (PLEs), as measured by the Community Assessment of Psychic Experiences-42 (CAPE-42) questionnaire, is mediated or moderated by lifetime cannabis use at 16 years of age in 1740 of the individuals of the European IMAGEN cohort. Secondary analysis examined the relationships between lifetime cannabis use, PRS-Sz and the various sub-scales of the CAPE-42. Sensitivity analyses including covariates, including a PRS for cannabis use, were conducted and results were replicated using data from 1223 individuals in the Dutch Utrecht cannabis cohort.

PRS-Sz significantly predicted cannabis use (p = 0.027) and PLE (p = 0.004) in the IMAGEN cohort. In the full model, considering PRS-Sz and covariates, cannabis use was also significantly associated with PLE in IMAGEN (p = 0.007). Results remained consistent in the Utrecht cohort and through sensitivity analyses. Nevertheless, there was no evidence of a mediation or moderation effects.

These results suggest that cannabis use remains a risk factor for PLEs, over and above genetic vulnerability for schizophrenia. This research does not support the notion that the cannabis–psychosis link is limited to individuals who are genetically predisposed to psychosis and suggests a need for research focusing on cannabis-related processes in psychosis that cannot be explained by genetic vulnerability.

Cognitive models of adult psychosis propose that negative schematic beliefs (NSBs) mediate the established association between victimisation and psychotic symptoms. In childhood, unusual, or psychotic-like, experiences are associated with bullying (a common form of victimisation) and NSBs. This study tests the mediating role of NSBs in the relationship between bullying and distressing unusual experiences (UEDs) in childhood.

Ninety-four 8–14 year olds referred to community Child and Adolescent Mental Health Services completed self-report assessments of UEDs, bullying, and NSBs about the self (NS) and others (NO).

Both NS and NO were associated with bullying (NS: r = .40, P < .001; NO: r = .33, P = .002), and with UEDs (NS: r = .51, P < .001; NO: r = .43, P < .001). Both NS and NO significantly mediated the relationship between bullying and UEDs (NS: z = 3.15, P = .002; NO: z = 2.35, P = .019).

Children's NSBs may mediate the adverse psychological impact of victimisation, and are appropriate treatment targets for young people with UEDs. Early educational intervention to reduce negative appraisals of the self and others may increase resilience to future adverse experiences and reduce later mental health risk.

Psychotic symptoms, also termed psychotic-like experiences (PLEs) in the absence of psychotic disorder, are common in adolescents and are associated with increased risk of schizophrenia-spectrum illness in adulthood. At the same time, schizophrenia is associated with deficits in social cognition, with deficits particularly documented in facial emotion recognition (FER). However, little is known about the relationship between PLEs and FER abilities, with only one previous prospective study examining the association between these abilities in childhood and reported PLEs in adolescence. The current study was a cross-sectional investigation of the association between PLEs and FER in a sample of Irish adolescents.

The Adolescent Psychotic-Like Symptom Screener (APSS), a self-report measure of PLEs, and the Penn Emotion Recognition-40 Test (Penn ER-40), a measure of facial emotion recognition, were completed by 793 children aged 10–13 years.

Children who reported PLEs performed significantly more poorly on FER (β=−0.03, p=0.035). Recognition of sad faces was the major driver of effects, with children performing particularly poorly when identifying this expression (β=−0.08, p=0.032).

The current findings show that PLEs are associated with poorer FER. Further work is needed to elucidate causal relationships with implications for the design of future interventions for those at risk of developing psychosis.