Relation of Social Anhedonia with Social Anxiety, Depression and Schizophrenia Symptoms in ASD and Psychiatry Referrals.

Background:  Social anhedonia (SA), a preference for being alone, is an accepted symptom phenotype in autism spectrum disorder (ASD), depression (MDE), and schizophrenia spectrum disorder (SSD); nevertheless, it remains under-investigated. It is unknown what drives SA in ASD: lack of pleasure from social interaction, social anxiety or fear of social humiliation (Asendorpf, 1990), or lack of skills to engage in social interaction.

Objectives:  We sought to characterize the clinical correlates of SA and social anxiety in youth with ASD and non-ASD psychiatry referrals. To distinguish between fear of, versus desire for, social interaction, we investigated co-occurring social anxiety and SA. First, we characterized the prevalence and severity of SA and social anxiety between clinical groups. Next, within the ASD sample, we explored whether youth with SA evidenced more severe social deficits, social anxiety versus other forms of anxiety, and co-occurring commonly studied clinical correlates such as MDE, SSD and intellectual disability (ID).

Methods:  Participants were youth with ASD (N=283) and non-ASD psychiatry referrals (N=653) between 6-18 years. Parents completed assessment batteries including the Child and Adolescent Symptom Inventory–4R (CASI-4R; Gadow & Sprafkin, 2005), Parent Questionnaire (Gadow et al., 2008), and Social Communication Questionnaire Lifetime Version (SCQ; Berument et al., 1999). Based on CASI-4R, youth were considered: socially anhedonic (SA), diminished social interaction (DS), or none (NONE).

Results:  Rates of SA were higher in ASD (33%) than non-ASD clinic referrals (10%; X²(2) = 138.64, p < .001). Similarly, rates of social anxiety disorder were higher in ASD (28%) than non-ASD youth (13%; X²(2) = 19.38, p < .001). Among ASD youth, social anxiety disorder rates were significantly greater for SA (49%) compared to DS (30%) and NONE (7%; X²(2) = 39.88, p < .001). There was a significant main effect for SCQ social deficits (F = 19.4, p < .001) in ASD; Tukey’s post-hoc showed SA and DS youth were comparable but more severe than NONE (p < .001). There was a significant main effect for social anxiety disorder symptoms (F = 24.2, p < .001) in ASD; Tukey’s post hoc showed SA youth evidenced more symptoms (but not other anxiety disorder symptoms) than both DS and NONE (p < .001). In contrast, non-ASD SA youth evinced greater symptoms of social and non-social anxiety disorders compared to DS and NONE (all p < .05). A main effect was found for MDE and SSD (F > 12.3, p < .001) in ASD; Tukey’s post hoc showed that SA youth evinced more symptoms than DS and NONE for both disorders (p < .001). SA was not associated with ID in ASD youth (X²(2) = 3.15, p > .05).

Conclusions:  SA was found to be more common in ASD than non-ASD psychiatry referrals, yet it is not a defining characteristic of ASD. More importantly, only within ASD, SA youth evinced more social anxiety disorder symptoms but not other anxiety disorder symptoms compared to DS youth, suggesting that social anxiety may be driving SA. Interventions targeting social anxiety may therefore benefit SA youth.