Research indicates that visual integration impairment is characteristic of psychosis and not specific to schizophrenia or other diagnostic categories, according to findings published in Psychiatry Research.
Researchers compiled demographic and clinical characteristics of 116 participants: 25 with schizophrenia, 22 with schizoaffective disorder, 31 with bipolar disorder with (n=11) or without (n=20) a history of prominent psychosis, and 38 healthy controls. Visual integration capacity was captured using a Contour Integration task. General cognition was measured using the Brief Assessment of Cognition in Schizophrenia.
Clinical features of each patient were also assessed, including positive and negative symptoms of schizophrenia disorder and manic and depressive symptoms. Researchers then stratified participants based on 3 separate grouping models: the Psychosis Model, the Schizophrenia Model, and the Diagnostic and Statistical Manual of Mental Disorders (DSM) Model. Bayesian model comparison was utilized to determine which of the 3 models was most effective as a predictor of visual integration performance in the participants.
According to one-way ANOVA analysis on visual integration performance, a significant group effect was observed when participants were stratified by diagnosis (P =.026). When grouped by the Psychosis Model, individuals with psychosis had significantly worse visual integration thresholds than individuals without psychosis (P =.002). When grouped by the DSM model, participants with schizophrenia and schizoaffective disorder had significantly lower visual integration scores than healthy controls (P =.024 and P <.05, respectively). According to the Bayesian comparison analysis, the Psychosis Model had the strongest predictive effect for a difference in Contour Integration performance. General cognition was significantly associated with visual integration performance, with poorer cognition predictive of impaired visual integration (P <.05).
These results indicate that impaired visual integration in patients with schizophrenia may more broadly be a feature of psychosis, rather than specifically of schizophrenia. Study data also suggest that visual integration impairment may share “common pathophysiologic pathways” with the abnormal neurocognition observed in psychosis. Additional research is needed to further elucidate the effects of psychosis on visual integration, as well as other psychopathologic dimensions across diagnostic groups.
Grove TB, Yao B, Mueller SA, et al. A Bayesian model comparison approach to test the specificity of visual integration impairment in schizophrenia or psychosis [published online May 7, 2018]. Psychiatry Res. doi:10.1016/j.psychres.2018.04.061