Pathways to psychosis: a comparison of the pervasive developmental disorder subtype Multiple Complex Developmental Disorder and the "At Risk Mental State".

BACKGROUND The comparison of high-risk populations with different developmental pathways to psychosis may lend more insight into the heterogeneity of the manifestation of the psychotic syndrome, and possible differing etiological pathways. AIM To compare high-risk traits and symptoms in two populations at risk for psychosis, i.e. (1) help-seeking adolescents presenting with prodromal symptoms meeting the criteria for At Risk Mental State (ARMS), and (2) adolescents with Multiple Complex Developmental Disorder (MCDD), a PDD-NOS subtype characterized by severe, early childhood-onset deficits in affect regulation, anxieties, disturbed social relationships, and thought disorder. METHOD 80 ARMS- and 32 MCDD-adolescents (12-18 years) were compared on prodromal symptoms (Structured Interview of Prodromal Symptoms, and Bonn Scale for the Assessment of Basic Symptoms-Prediction list), and autism traits (Social Communication Questionnaire). In addition, both high-risk groups were compared with 82 healthy controls on schizotypal traits (Schizotypal Personality Questionnaire-Revised). RESULTS Although the high-risk groups clearly differed in early developmental and treatment histories as well as autism traits, they did not differ with regard to schizotypal traits and basic symptoms, as well as disorganized and general prodromal symptoms. There were, however, group differences in positive and negative prodromal symptoms. Interestingly, 78% of the adolescents with MCDD met criteria for ARMS. CONCLUSION These findings suggest that children diagnosed with MCDD are at high risk for developing psychosis later in life, and support the notion that there are different developmental pathways to psychosis. Follow-up research is needed to compare the rates of transition to psychosis in both high-risk groups.