Bridging the gap between schizophrenia and psychotic mood disorders: Relating neurocognitive deficits to psychopathology

Background: The neurobiological relationship between schizophrenia and psychotic mood disorders is not well understood. Neurocognitive deficits have been described in both types of disorders and have been proposed to reflect underlying neurobiological dysfunction. Examining the relationship between neurocognitive function and psychopathology could help illuminate the neurobiological relationship between schizophrenia and psychotic mood disorders. Methods: Participants included 72 individuals with DSM-IV schizophrenia, 25 individuals with schizoaffective disorder or bipolar disorder with psychotic features, and 72 community controls. Standardized scores and correlations between four domains of neurocognition and psychopathology were examined. Results: Individuals with schizophrenia and psychotic mood disorders scored similarly on several dimensions of neurocognitive function and psychopathology. The relationships between neurocognitive function and psychopathology were similar in the two groups. Conclusions: Individuals with schizophrenia and psychotic mood disorders were similar in terms of both the level of impairment in neurocognitive function and psychopathology, as well as in the relationship between the two dimensions of illness. These results suggest that schizophrenia and psychotic mood disorders such as schizoaffective disorder and bipolar disorder with psychotic features are on a neurobiological continuum.