Clinical and cognitive risk factors for psychotic symptoms in 22q11.2 deletion syndrome: a transversal and longitudinal approach

22q11.2 deletion syndrome (22q11DS) is associated with increased risk for schizophrenia. Better identifying risk factors for the emergence of psychotic symptoms in this population is needed to improve clinical assessment and early interventions. Schizophrenia spectrum disorders, hallucinations and delusions were characterized in an original sample of 104 individuals with 22q11DS. Further analysis of positive and negative symptoms was performed in a subsample of 59 individuals. Finally, longitudinal data available in 56 patients were used to explore the developmental trajectories of psychotic symptoms as well as the associations between psychotic symptoms and cognitive functioning. Schizophrenia spectrum disorders and psychotic symptoms were frequent in adolescent and adults with 22q11DS. The severity of hallucinations and non-persecutory delusional ideas discriminated patients at ultra-high risk for conversion to psychosis. Whereas approximately one-third of patients experienced an emergence of psychotic symptoms during a 4-year interval, 20 % displayed transient symptoms. Individuals with psychotic symptoms were characterized by a lower cognitive functioning in the context of the 22q11DS. The present study adds important data on the characteristics and developmental trajectory of psychotic symptoms in this population. This information may ultimately help clinicians dealing with these patients to reduce the duration of untreated psychosis and improve outcome.