Using the DISCO to Understand Associated Symptoms and Associated Developmental Conditions

Background:  The Diagnostic Interview for Social and Communication Disorders DISCO) is the only diagnostic schedule to gather information on the full spectrum of autistic behaviours and developmental skills. This broad focus includes the collection of information on many behaviours and developmental skills that lie outside of the standard ‘core’ set of diagnostic features (i.e. social interaction, communication and repetitive behaviours). For example the DISCO includes multiple items on sensory atypicalities, motor skills, catatonic features, self-care skills, literacy, maladaptive behaviours, emotional responses, psychiatric conditions and forensic problems. This makes it possible to study the nature of the relation between these features and traditional ‘core’ features. It has also enables the study of ASD features in a range of different genetic and neurodevelopmental conditions in which ‘core’ symptoms are only partially seen. 

Objectives:  a) To study the pattern of core and ‘non-core’ symptoms seen in individuals diagnosed with ASD (b) to study patterns of both types of behaviours in individuals with different genetic and neurodevelopmental conditions.

Methods:  The DISCO interview schedule was administered by trained clinicians in the UK and in the Netherlands. Patterns of DISCO items within individuals with ASD were analysed using a database from 200 individuals. Patterns of overlapping behaviours across different conditions were investigated from the DISCO data of 37 individuals with Cornelia de Lange Syndrome, 52 females with Rett Syndrome, 22 individuals with Williams Syndrome, and 60 children with and without epilepsy.

Results:  (a) Patterns of behaviours in individuals diagnosed with ASD revealed that ‘non-core’ features were strongly associated with ‘core’ features but some classes of non-core features (e.g. sensory atypicalities) were more strongly associated with the core diagnostic domains than were other classes of non-core features (e.g. atypical motor skills). (b) Results for patterns of overlapping behaviours in different neurodevelopmental conditions showed that a high percentage of the individuals with Rett Disorder (39%) and more than half of the Cornelia de Lange group (54%) also had Autistic Disorder. The Williams Syndrome group had distinctive ASD features in the social interaction domain. Children with both epilepsy and ASD differed from children with ASD without epilepsy by having more motor difficulties, developmental delays and challenging behaviours.

Conclusions:  The breadth of scope of the DISCO means that it elicits behavioural features that can inform us about ASD features in other developmental disorders and about non-ASD features that may influence the presentation and possibly the development of ASD.