Prevalence and incidence of psychotic disorders in 22q11.2 deletion syndrome: a meta-analysis.

22q11.2 deletion syndrome (22q.11.2DS) might be one of the strongest genetic risk factors for psychosis, but robust estimates of prevalence and incidence of psychotic disorders in this condition are not available. To address this gap, we performed a multistep systematic PRISMA/MOOSE-compliant literature search of articles reporting prevalence (primary outcome) or incidence (secondary outcome) of psychotic disorders in 22q11.2DS samples (protocol: https://osf.io/w6hpg) using random-effects meta-analysis, subgroup analyses and meta-regressions. The pooled prevalence of psychotic disorders was 11.50% (95%CI:9.40-14.00%), largely schizophrenia (9.70%, 95%CI:6.50-14.20). Prevalence was significantly higher in samples with a mean age over 18 years, with both psychiatric and non-psychiatric comorbidities and recruited from healthcare services (compared to the community). Mean age was also significantly positively associated with prevalence in meta-regressions (p < 0.01). The pooled incidence of psychotic disorders was 10.60% (95%CI:6.60%-16.70%) at a mean follow-up time of 59.27 ± 40.55 months; meta-regressions were not significant. To our knowledge, this is the first comprehensive systematic review and meta-analysis of the prevalence and incidence of psychotic disorders in 22q11.2DS individuals. It demonstrates that around one in ten individuals with 22q11.2DS displays comorbid psychotic disorders, and around one in ten will develop psychosis in the following five years, indicating that preventive approaches should be implemented systematically in 22q11.2DS.

Social cognition and real-life functioning in patient samples with 22q11.2 deletion syndrome with or without psychosis, compared to a large sample of patients with schizophrenia only and healthy controls.

Patients with the 22q11.2 deletion syndrome (DS) show an increased risk of developing a psychotic illness lifetime. 22q11.2DS may represent a reliable model for studying the neurobiological underpinnings of schizophrenia. The study of social inference abilities in a genetic condition at high risk for psychosis, like 22q11.2DS, may shed light on the relationships between neurocognitive processes and patients' daily general functioning. The study sample consisted of 1736 participants, divided into four groups: 22q11.2DS patients with diagnosis of psychotic disorder (DEL SCZ, N = 20); 22q11.2DS subjects with no diagnosis of psychosis (DEL, N = 43); patients diagnosed with schizophrenia without 22q11.2DS (SCZ, N = 893); and healthy controls (HC, N = 780). Social cognition was assessed through The Awareness of Social Inference Test (TASIT) and general functioning through the Specific Levels of Functioning (SLoF) scale. We analysed data through regression analysis. The SCZ and DEL groups had similar levels of global functioning; they both had significantly lower SLoF Total scores than HC (p < .001); the DEL SCZ group showed significantly lower scores compared to the other groups (SCZ, p = .004; DEL, p = .003; HC, p < .001). A significant deficit in social cognition was observed in the three clinical groups. In the DEL SCZ and SCZ groups, TASIT scores significantly predicted global functioning (p < .05). Our findings of social cognition deficit in psychosis-prone patients point to the possible future adoption of rehabilitation programmes, like Social Skills Training and Cognitive Remediation, during premorbid stages of psychosis.