People can be puzzled by the diagnosis they or their child have been given. Over the years, different terms have been used for autism. This reflects the different autism profiles presented by individuals, and the diagnostic manuals and tools used. Misdiagnosis adds to the range of terms people hear.

Autism profiles

Autism is a spectrum condition. All autistic people share certain difficulties, but being autistic will affect them in different ways.

These differences, along with differences in diagnostic approach, have resulted in a variety of terms being 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), 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 often use additional terms to help to describe the particular autism profile presented by an individual.

Some autistic people also have learning disabilities, mental health issues or other conditions.

Asperger syndrome profile

A clinician might describe a person as having an Asperger syndrome profile if they do not have learning disabilities and have good language skills (but still have social communication difficulties).

Read more about Asperger syndrome.

Demand-avoidant profile

A clinician might describe a person as having a demand-avoidant profile, or pathological demand avoidance (PDA), if they are driven to excessively avoid demands and expectations. Underpinning this avoidance is an extremely high level of anxiety about conforming to social demands and of not being in control of the situation.

Read more about pathological demand avoidance.


One of the most common mistakes made by clinicians lacking autism experience is to make a number of observations that don’t take the issues related to autism into account.

Sometimes they may observe issues such as a person's clumsiness (possible dyspraxia), reading difficulty (possible dyslexia), poor attention span (possible Attention Deficit Disorder), difficulty with social communication (semantic pragmatic disorder or social communication disorder), mental health issues, or behavioural issues and diagnose that as the main condition. They may miss the fact that autism is underlying the obvious difficulties seen on the surface.

If you don't understand, or have concerns about, the diagnosis that you or your child are given, discuss this with the professional who made the diagnosis. You can ask for a second opinion, and you have the right to complain if you're not happy about any aspect of referral, diagnosis or care that you or your child receive from an NHS service.

Diagnostic manuals

International Classification of Diseases, tenth edition (ICD-10)

The ICD-10 is the most commonly-used diagnostic manual in the UK.

It presents a number of possible autism profiles, such as childhood autism, atypical autism and Asperger syndrome. These profiles 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 not the most commonly used manual in the UK, DSM-5 is likely to have a significant influence on the next edition of the ICD. This manual 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 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.

Diagnostic criteria

The manual defines autism spectrum disorder as “persistent difficulties with social communication and social interaction” and “restricted and repetitive patterns of behaviours, activities or interests” (this includes sensory behaviour), present since early childhood, to the extent that these “limit and impair everyday functioning”.

In DSM-5, the terms ‘autistic disorder’, ‘Asperger disorder’, ‘childhood disintegrative disorder’ and ‘Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS)’ have been replaced by the collective term 'autism spectrum disorder'. This means that it’s likely that ‘autism spectrum disorder’ (ASD) will become the most commonly given diagnosis. 

Asperger syndrome

For many people, the term Asperger syndrome is part of their day-to-day vocabulary and identity, so it is understandable that there are concerns around the removal from DMS-5 of Asperger syndrome as a distinct category. Everyone who currently has a diagnosis on the autism spectrum, including those with Asperger syndrome, will retain their diagnosis. No one will ‘lose’ their diagnosis because of the changes in DSM-5.

Research found that using the appropriate techniques, the new DSM-5 criteria correctly identified people who should receive a diagnosis of ASD across age and ability. (Kent R.G. et al, 2013)

Specifiers for Autism Spectrum Disorder

DSM-5 has introduced specifiers to help the clinician to describe associated or additional conditions, eg intellectual impairment, language impairment, genetic conditions, behavioural disorder, catatonia.

One of the specifiers relates to the ‘severity’ of social communication impairments and restricted, repetitive patterns of behaviour. There are 3 levels: requiring support, requiring substantial support, requiring very substantial support. This can allow the clinician to give an indication of how much someone’s condition affects them and how much support an individual needs.

However, people who receive a diagnosis are not automatically eligible for support. DSM-5 explains that ‘severity’ levels may vary by context and also fluctuate over time, that the descriptive severity categories should not be used to determine eligibility for and provision of services, and that 'these can only be developed at an individual level and through discussion of personal priorities and targets'.

Find out how to get extra help in school, social care and benefits.

Social (Pragmatic) Communication Disorder

The DSM-5 now includes a condition called 'social communication disorder', separate to 'autism spectrum disorder'. This would be given where someone exhibits social interaction and social communication difficulties and does not show restricted, repetitive patterns of behaviour, interests or activities. 

Diagnostic tools

The DSM and ICD-10 criteria create the foundation for diagnostic tools such as the DISCO (Diagnostic Interview for Social and Communication Disorders), the ADI-R (Autism Diagnostic Interview - Revised), and the ADOS (Autism Diagnostic Observation Schedule).

These, and other diagnostic tools, are used to collect information in order to help to decide whether someone is on the autism spectrum or not. The criteria form the basis for the diagnosis, but the individual clinician’s judgement is crucial.

The DISCO diagnostic tool does not rely on the algorithms for ICD-10 and DSM-5. The approach is dimensional rather than categorical. The DISCO not only gives a diagnosis but gives an understanding of the profile and needs.

Find out more about our specialist training in the diagnosis and assessment of autism.

Last reviewed 27 June 2016