Comparison of neurocognition, social cognition and jumping into conclusion bias in children of schizophrenia and bipolar disorder patients and healthy controls

Introduction and Objective: Schizophrenia and bipolar disorder are neurodevelopmental disorders with high genetic risk and impairments in neurocognitive and social cognitive functions have been investigated as endophenotypic markers in children of these patients in previous studies. Jumping to conclusion (JTC) bias has been found to predict psychosis in both healthy controls and those at familial risk for psychosis in previous studies. However, no studies examined these factors together. In this study, adult children of patients with schizophrenia and bipolar disorder with familial risk were compared with healthy controls in terms of neurocognition, social cognition and outcome attribution bias. We hypothesised that neurocognitive functions, social cognition, and jumping to conclusions would be more impaired in adult children of patients with schizophrenia and bipolar disorder compared to healthy controls and that children of patients with schizophrenia would be more impaired than children of patients with bipolar disorder in termes of these functions. Materials and Methods: Our study was conducted in adult children of schizophrenia and bipolar patients who were followed up in Bolu Abant İzzet Baysal University Faculty of Medicine Department of Psychiatry and in Community Mental Health Center of Bolu İzzet Baysal Mental Health Hospital who agreed to participate in the study. A total of 79 participants, including 26 adult children of patients with schizophrenia, 27 adult children of patients with bipolar disorder and 26 healthy controls were included in the study. Participants were evaluated with a clinical and sociodemographic form. Positive and Negative Syndrome Scale, Bipolar Prodrome Symptom Scale, Global Assessment of Functioning Scale (GAF), Thought Language Scale to assess thought disorders, Dokuz Eylül Theory of Mind Scale and Reading the Mind Through Eyes Test to assess theory of mind, Ekman Facial Emotion Recognition Test to asses emotion recognition from faces, Digit Span and Stroop Test to assess working memory and attention, Wisconsin Card Sorting Test to assess executive function and beads-in-a-jar test to assess jumping to conclusion bias were administered to all participants. Results: In our study, adult children of schizophrenia and bipolar disorder patients had a worse functioning compared to healthy controls. ToM functions of both groups were worse than healthy controls and ToM impairments and emotion recognition from faces were associated with executive function, working memory and attention disorders in both group. Impairment in working memory differentiated being a child of bipolar or schizophrenia patient and impairment in ToM differentiated being a child of schizophrenia and/or a bipolar patient from being healthy. PANSS general and total scores of adult children of bipolar disorder patients were higher than the other groups, executive functions assessed by WCST were worse than the other groups, and impairment in attention was associated with and predicted the frequency and severity of prodromal symptoms. Verbal working memory was more impaired in adult children of schizophrenia patients than other groups, impairment in verbal working memory was associated with general psychotic symptom severity, language-thought disorders and theory of mind impairments, negative symptoms were associated with social cognition and neurocognition. Language and thought disorders were associated with impairments in executive function and social cognition both in adult children of bipolar disorder and schizphrenia patients but, especially in the children of schizophrenia patients. Impairment in the recognition of the disgusted emotion predicted the severity of negative symptoms; inhibition inability and ToM impairment predicted language and thought disorders in the adult children of schizophrenia patients. Impaired social cognition was associated with and predicted the severity of PANSS in all participants. Conclusion: In our study, lower functioning and impairments of theory of mind were found in the children of both groups of patients compared to healthy controls and these impairments were associated with impairments in executive function-attention and working memory. Adult children of patients with schizophrenia showed more pronounced impairment especially in verbal working memory, whereas adult children of patients with bipolar disorder showed more pronounced impairment especially in executive functions. Therefore, longitudinal studies examining the change in neurocognitive and social cognitive functions over time in these individuals in the genetic risk group may help us both to monitor the developmental processes of these individuals and to better understand the risk factors of conversion to schizophrenia and bipolar spectrum disorder. Keywords: Schizophrenia, Bipolar disorder, high genetic risk, adult children, neurocognition, social cognition, jumping into conclusion bias, thought and language disorders