Autism - definitions
Understanding Autism - definitions and associated conditions
Autism is a lifelong, developmental disability that affects how a person communicates with, and relates to, other people, and how they experience the world around them.
Autism is a spectrum condition. All autistic people share certain difficulties, but being autistic will affect individuals in different ways.
These differences, along with differences in diagnostic approach, means that a variety of terms have been used to diagnose autistic people. Terms that have been used include Autism, Autism Spectrum Disorder (ASD), Autism Spectrum Condition (ASC), atypical Autism, classic Autism, Kanner Autism, Pervasive Developmental Disorder (PDD), High-Functioning Autism (HFA), Semantic Pragmatic Disorder (SPD), Asperger Syndrome and Pathological Demand Avoidance (PDA).
Because of recent and upcoming changes to the main diagnostic manuals, 'Autism Spectrum Disorder' (ASD) is now likely to become the most commonly given diagnostic term. However, clinicians will still sometimes use additional terms to help to describe the particular Autism profile presented by an individual.
Diagnostic manuals
International Classification of Diseases, tenth edition (ICD-10)
The ICD-10 is the most commonly-used diagnostic manual in the UK.
It includes a number of Autism profiles,including atypical Autism, childhood Autism and Asperger syndrome. These are included under the Pervasive Developmental Disorders heading, defined as "A group of disorders characterized by qualitative abnormalities in reciprocal social interactions and in patterns of communication, and by a restricted, stereotyped, repetitive repertoire of interests and activities. These qualitative abnormalities are a pervasive feature of the individual's functioning in all situations".
A revised edition (ICD-11) is expected in 2018 and is likely to closely align with the latest edition of the American Diagnostic and Statistical Manual (DSM).
Diagnostic and Statistical Manual, fifth edition (DSM-5)
Although DSM-5 is not the most commonly used manual in the UK it is likely to have a significant influence on the next edition of the ICD. The DSM V has recently been updated and is also used by diagnosticians.
The diagnostic criteria are clearer and simpler than in the previous version of the DSM, and sensory behaviours are now included. This is very useful as many autistic people have sensory issues which affect them on a day-to-day basis. It now includes 'specifiers' to indicate support needs and other factors that impact on the diagnosis.
DSM lists the following criteria as key characteristics of Autism.
A. Persistent deficits in social communication and social interaction across contexts, not accounted for by general developmental delays, and manifest by all 3 of the following:
- deficits in social-emotional reciprocity
- deficits in nonverbal communicative behaviours used for social interaction
- deficits in developing and maintaining relationships
B. Restricted, repetitive patterns of behaviour, interests or activities as manifested by at least two of the following:
- stereotyped or repetitive speech, motor movements, or use of objects
- excessive adherence to routines, ritualized patterns of verbal or nonverbal behaviour or excessive resistance to change
- highly restricted, fixated interests that are abnormal in intensity or focus
- hyper- or hypo-reactivity to sensory input or unusual interest in sensory aspects of the environment
C. Symptoms must be present in early childhood (may not become fully manifest until social demands exceed limited capacities)
D. Symptoms together limit and impair everyday functioning
