Dissociation of Brain Activation in Autism and Schizotypal Personality Disorder During Social Judgments.

Andrew C Stanfield,Ruth C M Philip,Jeremy Hall,Eve C Johnstone,Liana Romaniuk,Heather Whalley,Stephen M Lawrie

doi:10.1093/schbul/sbx083

Abstract

BackgroundThere are overlaps between autism and schizophrenia but these are particularly pronounced, especially in social domains, for higher functioning individuals with autism spectrum disorders (ASD) or schizotypal personality disorder (SPD). It is not known whether these overlapping social deficits result from shared or distinct brain mechanisms. We therefore compared social cognition in ASD and SPD using functional magnetic resonance imaging (fMRI).MethodsTwenty-one individuals with SPD, 28 with ASD and 33 controls were compared with respect to clinical symptoms using the Positive and Negative Syndrome Scale; social cognition, using a social judgment task and Ekman 60 faces task; and brain activation using an fMRI task of social judgment.ResultsThe ASD and SPD groups showed few differences in symptoms or social cognition. However, fMRI showed that, compared to ASD, the SPD group showed significantly greater activation during social compared to gender judgments in the amygdala and 3 clusters: right posterior cerebellum, extending into fusiform and inferior temporal gyri; left posterior cerebellum; and left intraparietal sulcus extending through medial portions of the temporal gyri into the fusiform gyrus (all P < .05 family-wise error corrected). Control activations lay between the ASD and SPD groups.ConclusionsAlthough social cognitive deficits in ASD and SPD appear superficially similar they are the result of different brain mechanisms. These findings have implications for therapeutic interventions targeted at social dysfunction in these conditions.

Highlights

The term autism was initially coined by Bleuler in 1911 to describe a characteristic symptom of people with schizophrenia, ‘detachment from reality, together with the relative and absolute predominance of the inner life.’[1]. It was first used to describe a specific disorder by Kanner in 1943, when he presented a case series of children affected by ‘autistic disturbance of affective contact.’[2] initially thought to be a distinct condition, autism soon came to be regarded as a form of early onset schizophrenia[3] and this continued until a series of studies differentiated the disorders on phenomenology, course and family history.[4,5,6,7,8,9]
Autism spectrum disorders (ASD) and ‘schizophrenia spectrum disorders’, such as schizotypal personality disorder (SPD), would be expected to differ on the level of mild psychotic symptoms and on restricted repetitive behaviours,[10] there are significant overlaps between the conditions: both occur in non-intellectually disabled people and are associated with social difficulties, idiosyncratic language and unusual behaviour, as well as showing common associated psychopathology.[11,12,13,14,15,16,17,18,19,20,21,22,23,24]
The clinical groups all showed similar patterns of impairment compared to controls in negative symptoms and the social cognition tests, but clear differences were seen between the autism spectrum disorders (ASD) and SPD groups using functional magnetic resonance imaging (fMRI) during the social judgement task

Summary

Introduction

The term autism was initially coined by Bleuler in 1911 to describe a characteristic symptom of people with schizophrenia, ‘detachment from reality, together with the relative and absolute predominance of the inner life.’[1]. There are overlaps between autism and schizophrenia but these are pronounced, especially in social domains, for higher functioning individuals with autism spectrum disorders (ASD) or schizotypal personality disorder (SPD). It is not known whether these overlapping social deficits result from shared or distinct brain mechanisms. We compared social cognition in ASD and SPD using functional magnetic resonance imaging (fMRI)

Methods

Results

Conclusion