The influence of Autism traits on the manifestation of Obsessive-compulsive and Hoarding symptoms

Abstract

Introduction: Empirical research in recent years has evidently demonstrated an overlap between Autism spectrum disorder (ASD) on the one hand and Obsessive-compulsive disorder (OCD) and Hoarding disorder (HD) on the other. The current study has explored to what extent individuals with OCD and HD, with or without comorbid ASD traits, differ in the manifestation of their disorders. Method: A total of 59 individuals (22 HD, 18 OCD, 21 controls) encompassed this explorative study. A dichotomy was created among the HD and OCD patients by using a cut-of of scores on the Autism Questionnaire (AQ), resulting in the creation of OCD and HD groups with and without ASD symptoms. Patients with OCD or HD and comorbid ASD were compared with patients with ‘pure’ (i.e. without ASD) OCD and HD patients, using the Obsessive-compulsive Inventory-Revised (OCI-R), the Saving Cognition Inventory (SCI), the Saving Inventory-Revised (SI-R), the Clutter Image Rating (CIR) and the Structured Interview of Hoarding Disorder (SIHD). Results: No between patient group differences were found on the total scores and five out of six subscales of the OCI-R.However, OCD + ASD patients did score significantly higher on the ‘ordering’ symptom subscale of the OCI-R than ‘pure’ OCD patients. With regard to the HD patients, both groups showed equally elevated scores on the SCI, SI-R and the CIR. The qualitative part of the analyses suggested that two out of the seven HD patients with ASD showed hoarding behaviour evolving around circumscribed or ‘special’ interests, as opposed to one out of eleven ‘pure’ HD patients. Discussion: When individuals with OCD show comorbid autism traits, ordering symptoms seem to be more prominent. Further, Hoarding seems to point into a final common pathway of dysfunction regardless of ASD comorbidity in HD patients, although Hoarding behaviour in patients with co-morbid ASD does seem to be ccompanied with collecting items around a specific interest. Future research with larger study samples should replicate these findings.