Altered Fronto-striatal Resting State Connectivity in Compulsivity-related Neurodevelopmental Disorders

Abstract

Background: The disorders Obsessive Compulsive Disorder (OCD) and Autism Spectrum Disorder (ASD) share compulsivity-related symptoms and previous research has indicated that similar abnormalities in the functioning of fronto-striatal connections might underlie these shared symptoms. Nevertheless, previous studies have solely focused on one disorder at a time, hampering direct comparison. Furthermore, inconsistent findings might have occurred due to heterogeneity within diagnostic groups and a direct focus on overlapping symptom dimensions might generate more coherent results. Here, we addressed functional connectivity of fronto-striatal circuits in OCD and ASD as compared to healthy controls and additionally in relation to compulsive behaviour across groups. Methods: Resting state functional magnetic resonance imaging data was obtained from 25 children with ASD, 21 children with OCD and 24 healthy controls. Compulsive behaviour was assessed using the Repetitive Behavior Scale-Revised. A seed-based functional connectivity analysis was conducted by correlating the time series of eight seed regions within the striatum to the time series of voxels within the frontal lobe. Subsequently, we performed group comparisons of functional connectivity and analysed cross-disorder associations between functional connectivity and compulsive behaviour. Results: We detected no significant differences between ASD, OCD, and control groups. Across groups, more severe compulsive behaviour was related to lower functional connectivity between the nucleus accumbens and orbitofrontal cortex as well as lower connectivity between the caudate and supplementary motor area. Conclusions: The current results show that compulsivity is related to decreased fronto-striatal connectivity across disorders. The impaired circuits could underlie the inability to inhibit compulsive behaviour.