Attachment disorder in autism spectrum disorder and intellectual disability

Purpose Autism spectrum disorder (ASD) is an exclusion criterion for one of the two attachment disorders in the DSM 5. However, previous findings indicate that ASD and attachment disorder are unrelated conditions and may co-occur. The purpose of this paper is to explore the diagnostic assessment of an adolescent male with ASD, intellectual disability (ID), severe challenging behaviour and a suspected attachment disorder. Design/methodology/approach Case study methodology was chosen because of its suitability in the exploration of complex clinical phenomena where prior knowledge is sparse. Findings It was possible to identify symptoms of attachment disorder in a case involving ASD, ID, anxiety and severe challenging behaviour. The Disturbances of Attachment Interview was particularly useful in this assessment, as was assessment of ASD symptoms and developmental history. Differentiating the two attachment disorders proved challenging. Research limitations/implications There is a need for further research in ASD and attachment disorders not limited by current diagnostic categories. Practical implications Co-occurring symptoms of attachment disorder may be identified in individuals with ASD and ID, and exploration of these symptoms in assessments of children and adolescents with ASD/ID and challenging behaviour may be beneficial. Originality/value The study adds to previous findings on attachment disorder in ASD, demonstrating that identification of attachment disorder is possible even in the presence of a highly complex clinical picture involving severe challenging behaviour. It may also assist other clinicians in identifying and making more accurate assessment of attachment disorder in ASD and ID.