Psychiatric disorders in people with 22q11.2 Deletion Syndrome: A population-based prevalence study in Ireland

Background: 22q11.2 Deletion Syndrome (22q11.2 DS) is a common micro‐deletion syndrome associated with intellectual disability, brain abnormalities and a complex spectrum of psychiatric disorders in both adults and children. Many previous studies have shown that adults with 22q11.2 DS have approximately thirty times greater risk for the developing schizophrenia compared to the general population. Furthermore, studies of children and adolescents with 22q11.2 DS have found high rates of psychotic symptoms, ADHD and anxiety disorders. In this study we initially aim to characterize the psychiatric and neuropsychological phenotype of all individuals in Ireland with 22q11.2 DS and then correlate our findings with genetic association studies and brain imaging. We then intend to undertake a longitudinal study to assess for risk factors of future psychotic illness. Methods: Forty‐four individuals with 22q11.2 DS (Mean age = 14 years, SD = 9) were compared to 25 non‐affected sibling controls (Mean age = 12 years, SD = 4). Psychiatric phenotype assessment was performed using a range of standardized clinical assessments including, the Diagnostic Interview Schedule for Children (DISC), Psychotic Supplement of K‐SADS, Comprehensive Assessment of At Risk Mental State (CAARMS), the Schedule for Clinical Assessment in Neuropsychiatry (SCAN), Child Behaviour Checklist (CBCL) and the Social Communication Questionnaire (SCQ). Results: Preliminary data indicates that individuals in the 22q11.2 DS group have a higher prevalence of psychiatric disorders including; ADHD (41%), psychotic symptoms (19%), schizophrenia (2.7%), specific phobias (38%), depressive episodes (11%), and anxiety disorders (32%). Conclusion: This is the first stage in a longitudinal follow‐up study of individuals with 22q11.2DS in Ireland. Our preliminary results are consistent with previous findings of high rates of psychiatric disorders in people with 22q11.2DS. The challenge remains to identify precursor symptoms in childhood that predicts the later development of psychiatric disorders, particularly schizophrenia in this vulnerable group.