The Diagnostic Interview for Social and Communication Disorders (DISCO) was developed for use at The Centre for Social and Communication Disorders, by Dr Lorna Wing and Dr Judith Gould, as both a clinical and a research instrument for use with children and adults of any age.
There are no specific physical or psychological tests for autism spectrum disorders. In order to recognise and identify the impairments of social interaction, social communication and social imagination together with the associated repetitive behaviours, and all the other features that can be found in autistic disorder, information must be collected in a systematic way. This is achieved by using the DISCO, a detailed, semi-structured interview.
Its special value is that it collects information concerning all aspects of each individual’s skills, deficits and untypical behaviour not just the features of autism spectrum disorder. Where possible information concerning the individual’s history in infancy and childhood should be collected from an informant who has known the person concerned from birth. However when, for an adult, there is no informant available to give an early history, the items of the schedule can be completed for current skills, deficits and untypical behaviour.
If no developmental history is available, this does not allow for a diagnosis using the ICD or DSM classification systems, but the information gathered from the DISCO does allow the experienced clinician to use their clinical judgement to make a working diagnosis in order to plan a management programme.
Since the DISCO was designed a small number of other schedules for the diagnosis of autistic disorders have become available. The DISCO has certain important advantages as follows.
The DISCO is designed to elicit a picture of the whole individual through the story of their development and behaviour. In clinical work, the primary purpose is to facilitate understanding of the pattern over time of the specific skills and impairments that underlie the overt behaviour. As mentioned above sometimes no informant is available. When this is the case the clinician has to obtain as much information as possible concerning the details of current skills and pattern of behaviour of the individual. This type of dimensional approach to clinical description is far more useful for prescribing how to help each individual than is assigning a diagnostic category. The dimensional approach is fundamental to the DISCO in contrast to other diagnostic schedules.
The findings from the DISCO are relevant and helpful for children and adults of any age; for any level of ability from profound learning disability to the superior range, for any manifestation of the autism spectrum from the most obvious to the most subtle. It can also assist in identifying conditions often associated with the spectrum, such as ADHD, tics, dyspraxia and catatonia-like disorders.
For research, it has been adapted so that different diagnostic systems can be applied and compared. It is also useful for examining the patterns of clinical features and their significance for present behaviour and future prognosis.
It is also important to note that DISCO training courses are designed not only to teach how to use the schedule but also to increase understanding of the nature of autistic disorders and the wide variation in the ways they can be manifested.
As emphasised in the section on its history, the DISCO should be used in conjunction with psychological assessment, observation and any other sources of reliable information.