Evaluation of broad autism phenotype and handedness in patients with bipolar disorder

Abstract

Objective: Genome-wide association studies of psychiatric disorders have revealed a multiplicity of common genetic variants between bipolar disorder (BD) and autism. It has been established that the frequency of affective psychosis is greater in individuals with autism. However, studies of the frequency of autism spectrum symptoms and autism-related hand preference in patients with BD are limited. The aim of this study was to investigate the broad autism phenotype and dominant hand preference in BD patients. Method: A total of sixty-six (thirty-three female) patients of the Bakirkoy Prof. Mazhar Osman Training and Research Hospital for Psychiatry, Neurology, and Neurosurgery mood clinic diagnosed with bipolar I disorder who were in a euthymic period and 66 healthy controls matched for gender, age, and years of education were enrolled in the study. Sociodemographic and clinical characteristics of the patients were obtained from patient records, and the Autism Spectrum Quotient test (AQ) and Edinburgh Handedness Inventory self-report screening tools were administered. Results: The mean disease duration was 15.5±8.4 years and the mean age of onset was 21.3±5.1 years. The mean total AQ score was 22.9±4.9 in the patient group and 19.1±4.4 in the control group, which represented a statistically significant difference. The mean score for the AQ subscales of communication, imagination, and attention switching were also higher in the patient group, and the difference was significant. Regression analysis indicated that the presence of BD was predictive for a higher AQ score; gender and hand preference did not demonstrate predictive value related to the AQ score. Conclusion: The results of this research indicated that the broad autism phenotype was common in BD. The broad autism phenotype should be kept in mind to better understand the clinical features of BD patients. Additional evaluation of the effect of the phenotypes including hand preference on the course of BD should be conducted in studies with larger samples.