Diagnostic specificity of poor premorbid adjustment: comparison of schizophrenia, schizoaffective disorder, and mood disorder with psychotic features.

Individuals with schizophrenia have significant deficits in premorbid social and academic adjustment compared to individuals with non-psychotic diagnoses. However, it is unclear how severity and developmental trajectory of premorbid maladjustment compare across psychotic disorders. This study examined the association between premorbid functioning (in childhood, early adolescence, and late adolescence) and psychotic disorder diagnosis in a first-episode sample of 105 individuals: schizophrenia (n=68), schizoaffective disorder (n=22), and mood disorder with psychotic features (n=15). Social and academic maladjustment was assessed using the Cannon-Spoor Premorbid Adjustment Scale. Worse social functioning in late adolescence was associated with higher odds of schizophrenia compared to odds of either schizoaffective disorder or mood disorder with psychotic features, independently of child and early adolescent maladjustment. Greater social dysfunction in childhood was associated with higher odds of schizoaffective disorder compared to odds of schizophrenia. Premorbid decline in academic adjustment was observed for all groups, but did not predict diagnosis at any stage of development. Results suggest that social functioning is disrupted in the premorbid phase of both schizophrenia and schizoaffective disorder, but remains fairly stable in mood disorders with psychotic features. Disparities in the onset and time course of social dysfunction suggest important developmental differences between schizophrenia and schizoaffective disorder.