Autism - guidance

Definitions and Terminology

Throughout this guidance we use the term ‘autism’ to represent variations in the diagnostic terms used. We acknowledge that existing diagnostic manuals use ‘autism spectrum disorder – ASD’, others prefer ‘autism spectrum condition – ASC’.

We use identity-first language i.e. ‘autistic person’ as it is currently considered to be the most preferred term; others prefer ‘person with autism’ (see Bury, S.M., Jellett, R., Spoor, J.R. and Hedley, D., 2023). We respect and encourage prioritising individual preference (Kenny et al 2016; Botha et al 2021). When quoting from original sources we retain the language of the original article. We have aimed to include co-produced research; however, we are aware that many of the included references and resources are not, and do not, use neurodiversity affirming language.

This guidance takes a lifespan approach. We will use words such as people or individuals when referring to all ages, only specifying child/young person or adult when a statement refers specifically to that age group. We have acknowledged the range of presentations and co-occurring diagnoses in our recommendations. This means, for example, that some recommendations relate to autistic people and others for autistic people with a learning disability.

See the glossary for definitions of specific terms.

Setting the scene in autism: neurodiversity and the neurodiversity movement

In this section, we provide a brief summary of neurodiversity, introducing descriptive, philosophical and political terminology. Within neurodiversity, there is a diversity of perspectives and sensibilities. This guidance is focused on autism, whereas neurodiversity is broad and neurodivergences can be multiple. For further information on other neurodivergences, you may wish to explore other sources of information. This area continues to evolve and we encourage SLT to ensure their knowledge is up to date through checking sources and evaluating information critically.

Neurodiversity

Neurodiversity refers to the natural variation in human neurological development across society. It refers to the diversity of brains and minds and the way we experience and interact with the world or that there are different ‘neurotypes’.  While many follow the neurodevelopmental pathway of the majority i.e. neurotypical, others have neurodevelopment that diverges from this and may identify as neurodivergent. The term ‘neurodivergent’ was introduced by Kassiane Asasumasu in 2000 (Walker & Raymaker 2021) to simply refer to a brain that diverges from typical.

The neurodiversity paradigm

The neurodiversity paradigm (Walker 2014) states that in naturally occurring neurodiversity, one way of being is not better than another. There are different neurotypes just as there are different characteristics such as ethnicity or gender; and equally, that there is no ‘right’ characteristic or neurotype. Neurodiversity is affected by the same social dynamics as other characteristics such as inequalities of social power, unconscious bias and prejudice. The neurodiversity paradigm values the strength and creative potential of diversity.

The neurodiversity movement

The neurodiversity movement is a political movement and in the context of a heterogenous population, a diversity of views exists and there is not universal agreement with some of its ideas. It is important that all ideas are open to critical scrutiny, debate and discussion in order to progress towards a future with better understanding of all perspectives.

For a fuller perspective in autism, see:

• Kapp, S.K., 2020. Autistic community and the neurodiversity movement: Stories from the frontline (p. 330). Springer Nature.
•  Leadbitter, K., Buckle, K.L., Ellis, C. and Dekker, M., 2021. Autistic self-advocacy and the neurodiversity movement: Implications for autism early intervention research and practice. Frontiers in Psychology (p.782).

The neurodiversity movement developed from the Autism Rights Movement in the 1990s, who embraced the term neurodiversity, attributed to sociologist Judy Singer (Singer 1999). Neurodiversity has always referred to all people. It includes neurotypical people as well as those with neurological and developmental differences including autism and, for example, those with attention and hyperactivity differences or language or learning differences.

To promote the recognition of a minority group status for individuals who differ from the majority such as autistic people, Nick Walker introduced the term ‘neurominority’ (Walker 2014; Walker & Raymaker 2021), with the rest of the population referred to as the ‘neuromajority’. This movement is aligned with disability and human rights and is focused on social justice. It aims for the acceptance and inclusion of all people, eradicating stigma, and promoting equality for neurological minorities. Their overarching goal is a neurodiversity-affirming social model of disability.

For autistic people, in addition to existing human rights and equality and diversity legislation, the Neurodiversity Movement asks that:

• autistic and neurotypical stakeholders work together across health, education, social care and research to support this social justice movement.
• quality of life, including adaptive functioning (e.g. self-determination and rights, well-being, social relationships and inclusion, and personal development) is at the centre (Knapp 2020).
• support and interventions are strength-based (focused on improving subjective quality of life and wellbeing), with the assent or consent of the autistic person, acknowledging that a minority may require a Best Interest decision. See RCSLT Shared decision making and mental capacity guidance.
• autistic ways of being are accepted and preserved.
• autistic people are supported to follow their own developmental trajectory.
• competence is presumed (until proven otherwise).
• the Double Empathy Problem (Milton 2012) is considered:

“.. It is the idea that rather than viewing autistic social differences as inherent deficits, that we instead recognize that perhaps non-autistic miscommunication has just as much role in autistic social difficulties as autistic people themselves do. That non-autism is just as baffling to autistic people as autism is to non-autistic people..” The Double Empathy Problem – A Paradigm Shift in Thinking About Autism – Speaking of Autism….

The neurodiversity movement, aligned with the social model of disability, emphasises societal and environmental barriers as contributors to disability. Autism is seen to be a neurological difference with any disability arising as a result of living in a society designed largely for the neuromajority. Historically, the medical model, with its focus on deficits or impairments, has driven autism research (see Pellicano and Den Houting 2021) and the development of interventions. This has contributed to a focus on teaching autistic people skills so that they behave like the majority and appear ’normal’.  The neurodiversity movement does not oppose the medical model, valuing its importance in providing treatments for co-occurring mental and physical health needs. Their criticisms of particular treatments and intervention approaches are grounded in the belief that aiming to normalise someone’s behaviour is a form of ableism (i.e. discrimination, bias and prejudice against the disabled), inferring inferiority and favouring the non-disabled.

As the neuromajority are also neurodiverse, the negative connotations associated with the concept of behaving ‘normally’ is universally unhelpful. Supporters of the neurodiversity movement consider that such teaching risks causing an individual to mask their difficulties, which in turn can affect mental wellbeing (e.g. Cage & Troxell-Whitman 2019), and in some cases,  results in trauma (see e.g. Kerns, Newschaffer, and Berkowitz, 2015; Hoover 2015; Rumball, Happé, and Grey, 2020).

“While the movement disagrees with certain principles, means, and goals of interventions, with those caveats, it does support therapies to help build useful skills such as language and flexibility. It opposes framing these matters in unnecessarily medical or clinical ways;” (p.8 Knapp 2020)

Other models of disability have been summarised below to aid understanding of our previous explanations.

• Social model of disability: The social model centres the structure of society (social, cultural, political and environmental) as the main contributor to a person’s experience of disability as opposed to the individual’s differences from the majority. It focuses on removing societal barriers to inclusion and participation.
• Medical model of disability: This model places the individual’s ‘symptoms’ at the centre and that it is these ‘impairments’ that are directly disabling them and excluding them from society. This model, originating in physical disease, is focused on treating or curing impairments.
• The World Health Organisation’s (WHO) International Classification of Functioning (ICF), based on the Biopsychosocial Model, has been proposed as one way or bridging the gap between the medical and social model (Bölte et al 2021; Bölte 2023). For further information see ICF Core Sets for ADHD and autism – Karolinska Institutet
• Biopsychosocial Model (Engel 1977): The biopsychosocial approach systematically considers biological, psychological, and social factors and their complex interactions in understanding health, illness, and health care delivery. It suggests that how well a person manages in life is a complex interaction between all three factors. Assessment should identify which aspects of the three domains are the most important to promoting and supporting a person’s health and wellbeing.
• Other proposed models of disability include: The Affirmative Model of Disability (see Swain, J. and French, S., 2000. Towards an affirmation model of disability. Disability & society, 15(4), pp.569-582.)

Setting the scene in autism: RCSLT Neurodiversity statement

The RCSLT values that we live in a society that is enriched by diversity, including neurodiversity. We recognise that differences exist between individuals, rather than deficits, and recognise disability. The RCSLT encourages members to acknowledge and appreciate individual needs, the impact of these, and to value the rights and autonomy of all people.

In a society largely designed for the neuromajority, we commit to taking deliberate steps to develop neurodiversity affirming practice within our profession. We commit to understanding the needs and preferences of neurominorities such as autistic people, including listening to parents and carers of people who cannot make these decisions themselves. This includes the ways in which autistic individuals are excluded or included, the ways we can make adjustments to everyday expectations, interactions and environments, and the teaching and sharing of specific skills where this supports quality of life, inclusion and reduces risk and harm. In particular, our profession has a key role in optimising communication experiences via the use of a neurodiversity informed lens.

Setting the scene in autism: Terminology

Words matter

In addition to our use of ‘autism’ and identity first language, we present other important terms for consideration, acknowledging that language continues to evolve. As speech and language therapists (SLTs), we recognise that words matter and the language we use has an effect. We sometimes work within the confines of a medical model where there is a disconnect between the clinical diagnostic language of professional reports and the positively-framed, individually affirming language of formulation and intervention/support, even when needs and disability are clearly described.

We recognise the balance required in using the language of difference versus deficit in a society where resources are limited and access is restricted to those showing a ‘clinically significant impairment’ (see Jellett and Muggleton; 2022) and often with a request for a qualifier such as ‘severe’. We encourage SLTs to advocate for a neurodiversity-affirming approach in all areas of practice, including the multi-disciplinary team and with system leaders. We also acknowledge that at present the use of positive and inclusive language without reference to difficulties and challenges, could risk preventing access to services, obtaining a diagnosis and receiving support. In addition, this may indirectly invalidate reports from the individual and their family.

SLTs should base their selection of language style (deficit-based or positively framed and individually affirming) on the needs of the autistic person at that time and knowledge of local services’ access requirements. This should be clearly explained, discussed and agreed with the autistic person and/or their parents/carers, particularly where an autistic person lacks the specific mental capacity to make this decision. Subject to the resources of individual services, consideration could be given to producing two versions of a written document containing the same information using both language styles depending on the aim of the report i.e. accessing support or affirming a person. Two examples of neuroaffirmative style reports one for adults and one for children are provided in our resources (see also Role of SLT: Transitions – Sharing Information)

What does neurodiversity informed in the context of autism mean?

• Putting co-production at the heart of service delivery across health, education, social care and in research.
• Drawing on the knowledge of those with lived experience, being cognisant of autistic voices and neurodivergent led or co-produced resources and the experiences of parents/carers of individuals unable to make decisions for themselves.
• Recognising and valuing that being autistic or neurodivergent is a valid lived-identity – not a set of symptoms to be treated.
• Recognising sources of disability and having a difference not deficit and environment first mindset i.e. change the context not the person.
• Using strength-based approaches to developmental differences that focus on harnessing a person’s strengths, interests and abilities and aim to provide support and adaptations that affirm an individual’s neurodivergent identity, if this makes sense to the individual concerned. E.g. Autistica Action Briefing: Strengths-based Approaches.

How to use terminology

With a commitment to being neurodiversity affirming and with the caveat above, consider:

• asking the autistic individual (or their parent/carer/advocate when a person does not have the capacity to make a decision) about their preferences relating to language and terminology; e.g. ‘autistic person’ or ‘person with autism’. For further reading see Vivanti 2020 and Botha, Hanlon & Williams 2021.
• avoiding the use of functioning labels such as high or low functioning or severity indicators such as mild, moderate, severe in relation to autism. These risk ableism and stigma and can minimise or dismiss the needs of those described as high functioning. Think about ways to describe the level of an autistic person’s support needs during a particular time or place. You should also acknowledge that these may change over time and context. There will be times when it’s appropriate to use clinical language over affirming language. Everyone presents differently across settings and time and such qualifiers are likely subjective and variable.
• the audience and needs of the individual autistic person. Parents of newly diagnosed children may request these labels to increase their understanding of their child’s future. We encourage honest and open conversations with families more broadly regarding what can be known about their child’s developmental trajectory. We note that there is a non-mandatory recommendation by an international consortium of academics and people with lived experience, to use the term ‘profound autism’ as an opportunity to ensure those who are disabled with the highest support needs are recognised, highlighting their needs to ensure the development of and access to services across the world, including third world countries (Lord et al 2022). We recognise that there is continued debate regarding the use of this term. For comments and responses, see the resources section. We also acknowledge that various systems e.g. education, may use functioning descriptors to contribute to the allocation of funding bands.
• using the word difference instead of deficit or impairment, where appropriate and if preferred by the individual. Ensure needs, level of impact and disability are well defined.
• using the term co-occurring instead of co-morbid for additional diagnoses.
• referring to distress, decisions, actions and responses instead of challenging behaviour or behaviour that challenges. This approach focuses on the individual and their engagement rather than the difficulties these outcomes present for the people around them. We acknowledge that use of these terms remains common with families, and in other sectors and professions, which may require use of all terms initially to ensure there are no barriers to communication.
• taking an active role in advocating for the appropriate use of neuroaffirmative language for example when working in a multi-disciplinary context.

Setting the scene in autism: Overview

What is autism?

Autism is a disability affecting neurodevelopment and characterised by differences in:

• social interaction
• speech, language and communication,
• learning, thinking and processing,
• experiencing feelings,
• intensity of interests and sensory processing.

It is highly heritable, with many genes contributing. Co-occurring diagnoses are common, including learning disability, and it persists across the lifespan. It is usually associated with average intellect where it is considered part of the range of natural variation in neurodiversity, bringing both challenges requiring support and strengths (adapted from Mandy 2019). As many as 50% of autistic people have high support needs that continue throughout life (Lord et al 2022).

Some autistic people do not identify as disabled.

How common is autism?

Current global estimates vary but are increasing, with the median estimates of prevalence (the frequency of autism in a population at any one time) ranging from 0.6 – 1 in 100 being autistic (Salari et al 2022; Zeidan et al 2022). Across the world, the reported ratio of males to females is now considered to be 4:2 (ratio as specified in Zeidan et al 2022) and the proportion of those diagnosed with a co-occurring learning disability is estimated at 33% (Zeidan et al 2022). For children with a learning disability in the US, the proportion of those with the highest support needs is approximately 28%. These children require around the clock supervision, are non-speaking and often with epilepsy and self-injury (Hughes et al; 2023).

Within the UK estimates vary. In Scotland a population study using the 2011 Census indicated that 1.6% of the population had autism, and that of those, 20% had an additional learning disability (Kinnear et al 2020). This rate varied, seemingly dependent on which diagnosis was recorded first and whether it refers to a child or adult:

“Of the children and young people with intellectual disabilities, 3,756/9,396 (40.0%) additionally had autism, and of the adults aged 25 years and over with intellectual disabilities, 1,953/16,953 (11.5%) additionally had autism. Of the children and young people with autism, 3,756/25,063 (15.0%) additionally had intellectual disabilities, and of the adults aged 25 years and over with autism, 1,953/6,649 (29.4%) additionally had intellectual disabilities.” (p. 1063 Kinnear et al 2020)

In Northern Ireland, published statistics for school-aged children only (aged 4-15 at the start of the school year) indicates a prevalence rate of 5% within the school-aged population (see The Prevalence of Autism (including Asperger Syndrome) in School Age Children in Northern Ireland Annual Report 2023.

Trends in diagnosis are also changing, for example in the UK between 1998 and 2018, a 787% rise in incidence (newly diagnosed) was identified, with greater increases in adults, females and those without learning disability (Russell et al 2022; in Wales: Underwood et al 2022).

NOTE: The statistics above are only estimates at a single point in time and with limitations due to for example, research methodologies, variability in estimates, evolving trends in who are receiving diagnoses, the likelihood of under diagnosis in certain ethnic groups (e.g. de Leeuw, Happé & Hoekstra 2020) and lack of acknowledgement of gender diversity.

Diagnostic criteria

To assist in the diagnosis of autism in the UK, professionals involved in the diagnostic assessment, including speech and language therapists (SLTs), use one of two references. These references aim to provide standardised criteria to inform diagnostic decision making.

1. The International Classification of Diseases 11^th edition (ICD-11) provides the following summary: “Autism spectrum disorder is characterised by persistent deficits in the ability to initiate and to sustain reciprocal social interaction and social communication, and by a range of restricted, repetitive, and inflexible patterns of behaviour, interests or activities that are clearly atypical or excessive for the individual’s age and sociocultural context. The onset of the disorder occurs during the developmental period, typically in early childhood, but symptoms may not become fully manifest until later, when social demands exceed limited capacities. Deficits are sufficiently severe to cause impairment in personal, family, social, educational, occupational or other important areas of functioning and are usually a pervasive feature of the individual’s functioning observable in all settings, although they may vary according to social, educational, or other context. Individuals along the spectrum exhibit a full range of intellectual functioning and language abilities.” ICD-11 for Mortality and Morbidity Statistics (who.int)
2. The Diagnostic and Statistical Manual of Mental Health Disorders, 5^th Edition, Text revision (DSM-5-TR) (US based) provides the following description (NB specifications of the number of symptoms are required and examples of symptoms are provided but not included here). The DSM-5-TR requires that co-occurring diagnoses and severity are specified and it defines “severity levels” according to the degree of support required 1: requiring support; 2: requiring substantial support; 3: requiring very substantial support.

DSM-5 diagnostic criteria, for further details https://www.cdc.gov/ncbddd/autism/hcp-dsm.html

A. “Persistent deficits in social communication and social interaction across multiple contexts, currently or by history.

B. Restricted, repetitive patterns of behavior, interests, or activities, currently or by history.

C. Symptoms must be present in the early developmental period (but may not become fully manifest until social demands exceed limited capacities or may be masked by learned strategies in later life).

D. Symptoms cause clinically significant impairment in social, occupational, or other important areas of current functioning.

E. These disturbances are not better explained by intellectual disability (intellectual developmental disorder) or global developmental delay. Intellectual disability and autism spectrum disorder frequently co-occur; to make comorbid diagnoses of autism spectrum disorder and intellectual disability, social communication should be below that expected for general developmental level.”

How does autism present?

“When you know one person with autism, you know one person with autism.” (Dr Stephen Shore)

Autism across cultures

Interaction styles and social expectations are embedded in culture and society. Although many similarities exist across cultures, so do differences. To date, the majority of autism research from which much of our understanding has developed, is skewed towards high-income western countries and within this body, ethnic minorities are underrepresented (de Leeuw, Happé & Hoekstra 2020). As a result, it is likely that our knowledge of how autism presents, how we recognise, assess and diagnose, and how we provide interventions and support autistic people, risks being culturally biased.

It is known that the broad areas of difference in autism are the same across different ethnic groups around the world but that the specific features or examples can differ qualitatively, quantitatively and in their impact on daily living for the autistic individual (de Leeuw et al 2020).

Autism across age groups

Just like everyone, autistic people have their own individuality, personality and strengths which can change and develop across the life-course influenced by their experiences through life, society and the wider environment. It can be helpful, particularly in recognising autism pre-diagnosis, to consider what autistic features are most relevant across different age groups. The National Institute for Health and Care Excellence (NICE) Clinical guideline [CG128]: Autism spectrum disorder in under 19s: recognition, referral and diagnosis, has a helpful summary table for children. The NICE clinical guideline [CG142] for adults, provides a list of possible features to consider in Recommendations section 1.2.

Autism and individuals’ assigned female at birth (AFAB)

In the past, there has been an underrecognition of autism in individuals AFAB and concerns about misdiagnosis in this group. This led to the identification of a different presentation of autism, now acknowledged as non-gender exclusive. Assigned Male at Birth (AMAB) individuals may present with the type of presentation described here and equally AFAB individuals may present with more traditional descriptions of autism that were previously thought to be more associated with AMAB individuals. These may (or may not) be in the absence of gender identity differences. For further learning on the intersection of autism and gender identify and dysphoria – see Adapting health services to meet the needs of autistic people with gender dysphoria (Strang et al 2018; Cooper, Mandy, Butler & Russell et al 2022, Cooper, Butler, Russell & Mandy 2022).

Recognition of this presentation remains important for all individuals and is thought to refer to masked autism (see Pearson & Rose 2021). A summary of this different behavioural expression of autism is provided below; for further reading see for example: Bargiela et al 2016; Howe et al 2015; Zener 2019).  The cited research refers to girls and women and boys and men, although not inclusive, these terms have been retained for this summary. Hull and colleagues (2020) proposed the following key differences in core features of autism.

Autistic girls/women:

• are thought to have greater interest and intent in forming social relationships but may struggle to maintain such relationships and find conflict within them harder to manage.
• may either have fewer repetitive behaviours or intense interests or that these interests are in different areas to boys/men, and/or are in areas that are typical in non-autistic but with greater intensity. The perceived acceptability of the type of interest may mean that it causes fewer overt social problems but nevertheless it risks this feature being overlooked by parents/carers and professionals.

Other relevant differences

Autistic girls/women:

• are thought to internalise emotional difficulties, such as anxiety, depression, self-harm and eating problems, to a greater degree than autistic boys and men. When severe, these difficulties may mask autism symptoms and a co-occurring mental health problem diagnosed but not autism. Internalising difficulties rather than externalising them (more common in autistic boys and men), such as through aggression, may also contribute to the gender bias in recognition as their needs are further hidden.
• may be more likely to camouflage, mask or compensate for their differences. This refers to the conscious or unconscious use of techniques to hide differences when in a social context, often driven by anxiety in response to the attitudes and responses of others. The techniques can be developed implicitly or explicitly learned. Whilst this may have advantages in a specific situation, the cost over time to mental wellbeing can be significant and (Chapman et al 2022).

*for further reading about these well-established phenomena, see our resources section.

Self-identification

Increasingly, some adults and young people self-identify as autistic often in the wake of typically extensive research, driven by a desire to seek a greater understanding of themselves e.g. What it’s Like Being a Self-Diagnosed #ActuallyAutistic Adult – The Art of Autism (Uselton 2020). For some this has happened while waiting for formal assessment. For others, it follows their child’s diagnosis of autism as they explore the literature to enhance their understanding of their autistic child. A proportion go on to seek formal diagnosis but many do not due to barriers to diagnosis as an adult that include the limited availability of diagnostic services, long waits and professionals’ perceptions (Lewis 2017; Crane et al 2018). This is despite access to diagnosis being a right with all localities expected to have a diagnostic pathway (Autism Act 2009).

Some people find that knowing and seeing themselves as neurodivergent and not ‘wrong’ is enough and find seeking formal diagnosis unnecessary. This can be the case whether they would be considered as meeting the criteria or not. Self-identification is not without controversy, and can risk misdiagnosis, especially as clinical diagnosis is reached via consensus rather than the viewpoint of a single person. It also risks a person’s needs being under recognised. For example, not identifying co-occurring problems and missing the opportunity to receive support and access Government benefits (Self-Diagnosed Autism: A Valid Diagnosis? – Autism Parenting Magazine (Loftus 2022)).

SLTs should support adults to access diagnostic assessment. This can include signposting to relevant services and support groups.

Co-occurring diagnoses and differential diagnosis

The frequency of co-occurring disabilities with autism is high (e.g. Levy et al. 2010). Autism guidance from all four UK nations recommends identifying any additional co-occurring diagnoses including recognising an individual’s strengths and needs. Understanding a person’s profile in this way is essential in identifying intervention and support needs as well as considering the impact of additional differences, the identification of any recommended treatment for co-occurring diagnoses and reducing the risk of missed or delayed diagnosis. As people change across their lifespan, so may their profile and the addition of new diagnoses or changes to diagnosis may be required. For example, an anxiety diagnosis (or any other mental health problem) can be given independently of autism or anxiety may occur because autism could not initially be recognised.

A number of other neurodevelopmental diagnoses may co-occur with autism and can be difficult to distinguish from each other, particularly in early stages of development. These are:

• learning disability (also referred to in the literature as intellectual disability/intellectual developmental disorder)
• language disorders, attention deficit hyperactivity disorder (ADHD)
• tic disorders and developmental co-ordination disorder (DCD), which collectively are sometimes referred to as ESSENCE (Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations) (Gillberg 2010).

Other diagnoses also co-occur or may be an alternative explanation (a differential diagnosis) of an individual’s neurodivergence. Examples are included below – the first is relevant for children and young people, and the second for adults, noting overlaps and differences; both from the NICE autism guidelines.

Recommendations – Autism spectrum disorder in under 19s: recognition, referral and diagnosis (NICE CG128) (NB specific language disorder is now known as Developmental Language Disorder, with language delays referred to as speech language communication needs.)

“1.5.7 Consider the following differential diagnoses for autism and whether specific assessments are needed to help interpret the autism history and observations:

• Neurodevelopmental disorders:
  • specific language delay or disorder
  • a learning (intellectual) disability or global developmental delay
  • developmental coordination disorder (DCD).
• Mental and behavioural disorders:
  • attention deficit hyperactivity disorder (ADHD)
  • mood disorder
  • anxiety disorder
  • attachment disorders
  • oppositional defiant disorder (ODD)
  • conduct disorder
  • obsessive compulsive disorder (OCD)
• Conditions in which there is developmental regression:
  • Rett syndrome
  • epileptic encephalopathy.
• Other conditions:
  • severe hearing impairment
  • severe visual impairment
  • maltreatment
  • selective mutism.”

Recommendations – Autism spectrum disorder in adults: diagnosis and management (NICE CG142)

“1.2.10 During a comprehensive assessment, take into account and assess for possible differential diagnoses and coexisting disorders or conditions, such as:

• other neurodevelopmental conditions (use formal assessment tools for learning disabilities)
• mental disorders (for example, schizophrenia, depression or other mood disorders, and anxiety disorders, in particular, social anxiety disorder and obsessive–compulsive disorder)
• neurological disorders (for example, epilepsy)
• physical disorders
• communication difficulties (for example, speech and language problems, and selective mutism)
• hyper- and/or hypo-sensory sensitivities.”

These lists are not exhaustive and reflect the complexity of understanding an individual’s neurodevelopmental profile of strengths and needs. Below, we provide further examples. Though not a wholly evidence-based list, but drawing attention to other specific diagnoses or differences considered important by those with lived experience of autism and others. Being autistic does not preclude a person from having any other physical or mental health problem:

Other mental, behavioural and neurodevelopmental diagnoses or differences (listed alphabetically not by magnitude or prevalence in autism):

• childhood apraxia of speech/verbal dyspraxia
• dissociative disorders (including Dissociative Identity Disorder – DID)
• eating disorders (see PEACE and Babb et al 2021): including pica and Avoidant restrictive food intake disorder (ARFID) (see e.g. Farag et al 2021; Bryant-Waugh, R., Loomes, R., Munuve, A. and Rhind, C., 2021)
• foetal alcohol spectrum disorder (FASD) (see Home – National FASD)
• Fragile X
• functional neurological disorder
• gender dysphoria (see for example Strang et al 2018; Cooper, Mandy, Butler & Russell et al 2022, Cooper, Butler, Russell & Mandy 2022)
• personality disorders
• post-traumatic stress disorder (PTSD) and complex PTSD (C-PTSD)
• trauma: autistic individuals can experience Adverse Childhood Events (ACEs) and traumatic experiences both separate and related to their autism (see e.g. Kerns, Newschaffer, and Berkowitz, 2015; Hoover 2015; Rumball, Happé, and Grey, 2020)
• specific Learning difficulties e.g. Dyslexia, dyscalculia
• stammering/stuttering/dysfluency

Other physical health conditions:

• Ehlers-Danlos syndromes
• fibromyalgia
• gut problems
• hypermobility

Other differences:

• Pathological Demand Avoidance (PDA) – this is a much-debated term however the experience of demand avoidance or anxiety is one recognised by many (for discussion see O’Nions et al. 2017; Malik & Baird 2018; Green et al. 2018; Woods 2019).

Neurodevelopmental pathways to diagnosis

Traditionally, diagnostic pathways and guidance are centred around specific diagnoses, having separate pathways for autism, for ADHD and for mental health. Grey areas can exist as to how other needs are diagnosed, for example with learning disability, which tends not to have a well-defined pathway (calls for a NICE guideline on Learning Disability in children and young people have been made). Approaches to assessment that consider any possible neurodevelopmental diagnosis do exist but are typically in tertiary services. Diagnosis-specific pathways can make it challenging to fully understand a neurodivergent person’s profile and identify their support needs. It can mean that individuals seeking diagnosis may not have access to professionals with the breadth of knowledge of co-occurring needs and at best, may experience sequential long waits on different diagnostic waiting lists.

NHS resources are stretched. Waiting times for diagnosis are often long and (along with access to diagnosis) are a stated priority for the UK government. Professionals and stakeholder groups have expressed concerns over the ability to follow diagnostic guidance due to limited resources (NICE autism guidance surveillance 2021). In response to both the complexity of diagnosis in neurodevelopment and the impact of long waiting times on neurodivergent people and their families, many are calling for multi-diagnosis assessment pathways or neurodevelopmental pathways (e.g. Male, Farr & Reddy 2021; Rutherford et al. 2021; Rutherford & Johnson 2022; see also Embracing Complexity in Diagnosis (Embracing Complexity 2019).

Excerpt from Rutherford, M., & Johnston, L. (2022):

“There is clear evidence that different neurodevelopmental conditions defined as they are currently, usually co-occur and overlap and it is often the combination of individual profile or “neurotype” together with the environment, that determines support needs rather than diagnosis. One consequence of this development in diagnostic criteria, is that it supports the shift in clinical practice, away from a “single condition” focus towards “neurodevelopmental” pathways and a diversification of our approach to assessment, diagnosis, and intervention.”

Following the publication of the NHS Long Term Plan (2019), NHS England provided funding to trial a variety of new approaches to diagnosis across the region producing a National Framework in April 2023 (see  National framework and operational guidance for autism assessment services, NHS England 2023). England has also introduced the NHS Right to Choose legislation (see . Scotland, through the National Autism Implementation team (NAIT), recommend a shift towards a single neurodevelopmental pathway to diagnosis with progress being made e.g. some areas are currently testing new models aiming to roll out new neurodevelopmental diagnostic pathways in 2023.

See resources section for further reading

Collaborative practice and co-production

Accounting for the nature of autism, prevalence of associated diagnoses and impact, a range of professionals and services will be variably involved with an autistic person over the course of their life. Working in partnership with others across all levels is central to improving outcomes for autistic people. This includes co-production with those with lived experience of autism, parents/carers of autistic children and adults, and collaboration with the many other organisations (see resources section) and professional groups involved in supporting autistic people when developing services and conducting research. Involvement of autistic people has been historically lacking in these areas but with emerging progress and calls for change (e.g. Pukki et al 2022). Partnership working with autistic individuals and others includes understanding and respecting different perspectives, aiming for shared views and goals. We highlight the autistic parent/carer and neurodivergent co-workers, provide a list of key professionals and any associated published national guidance in the Resources section, and share information on supporting informed choice through Shared Decision Making and on co-production principles.

The autistic or neurodivergent parent

A significant proportion of speech and language therapists (SLTs) will work alongside parents in support of their child. Whilst the recommendations below can apply to all parents, we draw attention to the autistic parent.

With heritability of autism estimated to be between 50-96% (Colvert, Tick & McEwen 2015; Sandin et al 2014; Bai, et al 2019), we can anticipate that ma