Increased developmental deviance and premorbid dysfunction in early onset schizophrenia.

Abnormal neurodevelopment and poor premorbid function have been described in schizophrenia. It is unclear whether abnormalities in these domains are increased in patients with early onset schizophrenia (EOS; onset before the 18th birthday) and whether they act to precipitate the earlier onset of the disorder. To address these questions, we collected information based on maternal interviews about the premorbid function of 40 adolescents with recent onset schizophrenia and an equal number of healthy controls using the Developmental Scale Score, the Premorbid Schizoid and Schizotypal Trait Scale (PSST) and Premorbid Adjustment Scale (PAS). Data on the PSST and PAS were also available in 54 patients with adult onset schizophrenia (AOS; onset after the 20th birthday). Compared to healthy controls, EOS patients had (a). delayed speech milestones, difficulties in reading and spelling and greater overall developmental deviance; (b). poor premorbid adjustment in childhood, which became even more deviant in adolescence particularly in boys and (c). more schizophrenia spectrum traits. Both premorbid adjustment and personality traits were more abnormal in patients with increased developmental deviance suggesting the possibility that they represent different manifestations of ongoing abnormalities in developmental processes. EOS patients had more impaired premorbid adjustment in adolescence and schizophrenia spectrum traits compared to AOS cases. Age of onset was related to developmental deviance, premorbid schizophrenia spectrum traits and childhood adjustment in EOS patients only.