Comparison of neural substrates of temporal discounting between youth with autism spectrum disorder and with obsessive-compulsive disorder

Abstract

BackgroundAutism spectrum disorder (ASD) and obsessive-compulsive disorder (OCD) share abnormalities in hot executive functions such as reward-based decision-making, as measured in the temporal discounting task (TD). No studies, however, have directly compared these disorders to investigate common/distinct neural profiles underlying such abnormalities. We wanted to test whether reward-based decision-making is a shared transdiagnostic feature of both disorders with similar neurofunctional substrates or whether it is a shared phenotype with disorder-differential neurofunctional underpinnings.MethodsAge and IQ-matched boys with ASD (N = 20), with OCD (N = 20) and 20 healthy controls, performed an individually-adjusted functional magnetic resonance imaging (fMRI) TD task. Brain activation and performance were compared between groups.ResultsBoys with ASD showed greater choice-impulsivity than OCD and control boys. Whole-brain between-group comparison revealed shared reductions in ASD and OCD relative to control boys for delayed-immediate choices in right ventromedial/lateral orbitofrontal cortex extending into medial/inferior prefrontal cortex, and in cerebellum, posterior cingulate and precuneus. For immediate-delayed choices, patients relative to controls showed reduced activation in anterior cingulate/ventromedial prefrontal cortex reaching into left caudate, which, at a trend level, was more decreased in ASD than OCD patients, and in bilateral temporal and inferior parietal regions.ConclusionsThis first fMRI comparison between youth with ASD and with OCD, using a reward-based decision-making task, shows predominantly shared neurofunctional abnormalities during TD in key ventromedial, orbital- and inferior fronto-striatal, temporo-parietal and cerebellar regions of temporal foresight and reward processing, suggesting trans-diagnostic neurofunctional deficits.

Neural dysfunction during temporal discounting in paediatric Attention-Deficit/Hyperactivity Disorder and Obsessive-Compulsive Disorder

“…Previous research has established the importance of VMPFC/OFC and striatal regions in OCD ( Menzies et al, 2008 , Radua and Mataix-Cols, 2009 , Radua et al, 2010 , Saxena and Rauch, 2000 ), which are reliably activated during symptom provocation ( Rotge et al, 2008 ), dysfunctional during cognitive and reward tasks ( Page et al, 2009 , Remijnse et al, 2009 ), and highly relevant to TD ( Christakou et al, 2011 , Peters and Buchel, 2011 ). In line with this, we recently showed that adolescents with OCD had altered activation in VMPFC/OFC and left caudate during TD, as well as in DLPFC, IFG, AI, parietal lobes and cerebellum ( Carlisi et al, 2017b ).…”

Social and delay discounting in autism spectrum disorder

“…Although our findings of greater delay discounting in ASD are contrary to some studies, existing literature is mixed. Some researchers have found evidence for greater discounting of future rewards in ASD (e.g., Carlisi et al, ; Chantiluke et al, ; Murphy et al, ), but others have found no group differences (e.g., Antrop et al, ; Demurie et al, ; Karalunas et al, & Kouklari, Tsermentseli, & Monks, in press). One possible explanation is that most studies finding differences, including ours, examined adolescents and adults, whereas most studies showing no differences included children as young as 7 or 8.…”

“…Moreover, the well‐characterized neural correlates of discounting make such tasks a promising tool for understanding neurobiological mechanisms spanning disorders (Lempert et al, ; MacKillop, ). As the limited existing research on delay discounting in autism spectrum disorders (ASD) is mixed as to whether individuals with ASD show normative (e.g., Antrop et al, ; Demurie, Roeyers, Baeyens, & Sonuga‐Barke, ) or atypical discounting (e.g., Carlisi et al, ; Chantiluke et al, ; Murphy et al, ), and no studies have assessed social discounting in ASD, simultaneously investigating delay and social discounting in a single sample with autism could yield novel insight into cognitive processes underlying ASD.…”

“…In light of these potential insights into ASD, this study is the first to investigate delay and social discounting in a single ASD sample. We recruited adolescents and young adults, age ranges that have successfully completed discounting tasks in prior studies (e.g., Carlisi et al, ; Murphy et al, ), and compared their results to a TD group matched on age, sex, and IQ. Given inconsistencies in prior ASD delay discounting studies and the lack of research on social discounting in ASD, three potential hypotheses could be advanced: first, there might be no group differences on either social or delay discounting; second, there might be equivalent group differences on both tasks; and third, there might be an interaction between group and task type, such that one task might show larger group differences than the other.…”

Evaluation of the Social Motivation Hypothesis of Autism

“…Original ture with unreported relevant data from publications on related disorders or tasks. 31,34,45 The existing literature included conflicting results that were difficult to compare owing to varied sample age, different correction methods, and region of interest analyses, which inherently introduce bias. 46 This metaanalysis addressed these issues and revealed that ASD groups showed reward circuitry hypoactivation for both social and nonsocial rewards.…”