Identification and Diagnosis


This section describes some of the key signs of ASD at different ages and stages. It is aimed at practitioners who are likely to come across individuals with ASD in their day to day practice but who are not usually involved in making a diagnosis.

Possible signs and symptoms for children and young people are also contained in the NICE guidelines.

Infants and Young Children

Parents or carers might report concern and worry in relation to a number of developmental issues that might suggest ASD is a possibility. It is crucial to pay close attention to parents/carers’ concerns about language, social skills and unusual behaviours. Many studies document that parental concerns about developmental delays in their children are typically well founded. Research reports also indicate that it causes great stress to parents when they feel that professionals are not listening to accounts and concerns. It is not helpful, and potentially harmful, to tell parents not to worry or to wait and see. The NICE guidelines advise that the possibility of autism should be considered if there are concerns about development or behaviour but practitioners should keep in mind that there may be other explanations for individual signs and symptoms.

Practitioners should also be aware that they might recognise concerns that parents or carers have not yet identified. This might relate to the parent or carer’s expectations of what is “typical” for a child at a particular age and stage. Routine developmental checks may be helpful in eliciting any concerns relating to possible ASD.

See case study: Sam (delayed diagnosis)

Communication and Language

Although ASD is best characterised by difficulties in social interaction, parents/carers more commonly express concerns with speech delay and difficult behaviours in young children.

There are some key developmental delays to be aware of in the initial stages of becoming concerned. Listed are some key alerts in relation to communication.

Alerts for the practitioner:

  • Language delay or abnormal language use
  • Little attempt to communicate
  • Showing little interest in the speech of others
  • Language that consists mainly of immediate or delayed repetitions of what is heard
  • Spontaneous communication that is stereotyped or unusual
  • Loss of language or development that has slowed/stopped in relation to language skills (most commonly in the second year of life)

Social interaction & Emotional Expression

Difficulties in social interaction and understanding are a key feature of ASD. In young children it is especially important to consider the normal development of social interaction and understanding e.g. very young children might not show much interest in playing with peers but may play alongside other children.  It is also important to think about the opportunities that young children have to learn these skills e.g. are there other family members that the child can play with? Do they go to any group activities or daycare?

It should be noted that the fact that a child may give eye contact or affection does not exclude the diagnosis of an ASD. Many children with ASD do demonstrate affection and make eye contact, but on their terms. They can give eye contact and hugs, but may have difficulty in receiving these from others.

Alerts for the practitioner:

  • Limited use of non-verbal communication (eye contact, facial expression, body posture and gestures) in social situations
  • Difficulty sharing enjoyment with others
  • Lack of reciprocal interaction with others i.e interaction that is two way in nature
  • Ignoring other people or appearing relatively insensitive to their needs, thoughts or feelings
  • Difficulties in interacting with same-age peers and in forming friendships
  • Difficulties in reading other people's intensions, emotions and feelings
  • Saying and doing inappropriate things to others as a result of impaired social understanding

Social Imagination/Flexible Thinking

Children with ASD show a tendency to develop rituals, resistance to change and sometimes have unusually intense interests, These interests can significantly interfere with daily activities but can sometimes be used positively e.g. to help motivate a child to complete a less favoured task.

Interrupting these activities and interests can lead to distress as they do not know what to replace them with. Intererupting these activities might also lead to distress as the behaviour is serving a particular function for the child or helping them to cope.

The tendency towards obsessive behaviours found in ASD is thought to be qualitatively different from obsessive compulsive disorders (OCD). Individuals with an ASD usually gain enjoyment from their special interests and activities. Individuals with OCD on the other had, may feel drive to follow routines/actions and can be distressed by this. It is possible of course for an individual to have both ASD and OCD. Link to section on co-occuring conditions/NICE guidelines on differential diagnosis.

Alerts for the practitioner:

  • Limited or idiosyncratic make-believe and social play
  • Insistence on certain routines and activities
  • Becoming upset by minor environmental changes
  • Preoccupation with objects, (e.g. elements of play materials such as wheels or wrappings)
  • Stereotyped and repetitive motor mannerisms, for example hand or finger flapping or twisting, or whole body movements
  • Resistance to changes in familiar routines or actions (e.g. changing form liquid food to solids; changing clothes; changing routines)

Older Children Without Language Delay

A child or young person who did not exhibit delayed speech development and who is in the average or above average range of intellectual ability would previously have been diagnosed with Asperger’s Syndrome.  Recent changes to DSM diagnostic criteria now mean that under this diagnostic system the diagnosis of Autism Spectrum Disorder is given regardless of whether there are delays in language or other areas of development. However there may be differences in how those children and young people who have not shown significant early delays present compared to children where signs of ASD have been recognised at an earlier age. The diagnosis of Asperger’s Syndrome may still be given by clinicians using the ICD-10 diagnostic criteria.


Children and young people who have not shown significant delays in language development will still have a range of difficulties with aspects of communication.  They may have particular difficulty in using language flexibly, using and understanding non-verbal communication and recognising social communication cues.

Alerts for the practitioner:

  • Formal and stereotypical language, including conversational difficulties
  • Limited non-verbal communication to augment the verbal communication
  • "To-and-fro" conversations are lacking- conversations are more like monologues
  • Difficulty in using speech to communicate wishes or needs
  • Limited or unusual use of non-verbal communication (eye contact, facial expression, body posture and gestures) in social situations
  • Tendency towards literal interpretation of comments
  • Over-precise or pedantic speech (often perfect English)

Social interaction

The social difficulties of those who have not had language delays can be similar to other young people with ASD but often more subtle: they may miss the unspoken rules of social interaction and fail to ‘read’ social situations.

Problems are more likely to be focused upon social interaction and friendships. Many young people with ASD will be having difficulties fitting in with the social context they are in and many young people with ASD are bullied or rejected by peers. They make seek friends but be rejected due to their unusual or odd behaviour.

Alerts for the practitioner:

  • Limited or idiosyncractic make-believe and social play
  • Difficulty interacting with same-age peers and in forming friendships
  • Seems unaware of social conventions and codes of conduct
  • Little evidence of empathy
  • Difficulties in understanding their own emotions and those of others
  • Difficulties for others in 'reading' the emotions of the individual

Flexibility of thinking and behaviour

Special interests are common for children and young people with ASD. This can take the form of collecting specific items or a fascination with a topic. It can exclude other activities, and the person's life may be dominated by this activity. It may be necessary to explore whether the interest is more intense or more rigid than would generally be expected.

Alerts for the practitioner

  • Lack of flexibility in adapting to change
  • Unusually intense interests
  • Insistence on specific routines or rituals (e.g. taking a particular route)
  • Upset by minor environmental changes in familiar situations (e.g. ornaments being moved at home; change of décor)
  • Preoccupation with certain objects, activities or intellectual interests, which are sometimes unusual in quality or for their age (e.g. architectural terms; light fittings; paper)

See Case Study: Older Child - Sarah.

An Adult With An ASD

NICE guidelines on Adult diagnosis can be found here:

General Information

The core features of ASD, as described above, also apply to adults with ASD, and as with children and young people, the condition will be manifested differently in different individuals.

Awareness and identification of ASD in children has improved in the UK in recent years (Wing & Potter, 2002). However, the protocol for the diagnosis of adults tends to be less consistent and there may be an assumption that an individual will have been assessed at an earlier age. This is often not the case and a significant number of individuals will reach adulthood without having had a diagnostic assessment (Pilling et al, 2012).

  • Research by the National Autistic Society indicated that 56% of adults found it hard to get a diagnosis. For those who do not have the co-morbid intellectual disability or mental health condition it may be especially hard to access services (NAS, 2008, I Exist Campaign)
  • Undiagnosed adults are unlikely to have received appropriate support, either in their development or in their adult lives and they are very likely to have had their difficulties misinterpreted
  • They may well have developed additional problems as a result of previously having received the wrong type of treatment, or even punishment, for their behaviour
  • Often it will be these additional problems that bring them to the attention of the practitioner


Adults may initially appear to have good communication skills but it may gradually become apparent that they do not understand some of what is said to them.

Alternatively they may appear to have little expressive communication at all and be taking no interest in the communication of others. This can sometimes be misleading and the individual will in fact have more understanding of the situation than is apparent.

Alerts for the practitioner

An adult may present with one or more of:

  • A mismatch between expressive and receptive communication skills
  • Seemingly no interest in communicating, except to express needs or demands
  • Idiosyncratic communication style, often not reflecting age/cultural background
  • Limited awareness of the reciprocal nature of communication

Social interaction

Some adults with ASD will seem oblivious to the social world and focused entirely on their own needs. Others will be socially aware and seemingly have social understanding.

Adults with ASD often develop competent communication skills over time, at least at a superficial level, and these skills can serve to mask the social problems they are experiencing.

However, the social rules change with context and the requirement to 'fit in' is great,. A difficulty in this area may well provide the first clue that a patient has an ASD. Close, direct questioning will often reveal a history of social difficulties and rejection by peers.

Alerts for the practitioner:

  • The person shows more interest in objects than other people
  • The person is socially uninhibited
  • Interest in others seems limited to using them as either 'helper' or 'audience'
  • The person seems immature, looking and acting much younger than they actually are (even older adults)
  • The individual has a history of problems 'fitting in' and often has difficulty understanding why; (e.g. feels they have been victimised or bullied)
  • Appearance and dress is not in keeping with their age, background or culture

Flexibility of thinking and behaviour

Whatever the level of functioning, it is very common for adults with ASD to develop and depend on routines and rituals. These serve to provide an element of predictability and control. Whilst the same is true of children with ASD, it is important to appreciate the different context that applies for adults.

Specialist support services for adults are still relatively rare in the UK, and adults with ASD may have had little or no appropriate input from professionals and/or carers. Without the right level and type of support, rigid patterns of thought and behaviour may have grown and developed over many years.

Appointments may cause disruption to routines that may be very important to the individual concerned. In a clinical setting, therefore, rigidity of thinking and behaviour will often manifest itself as anxiety and distress at the unexpected change to routine caused by the appointment.

Alerts for the practitioner:

The individual may:

  • Present with a history of having interests and obsessions, often to the detriment of their own wellbeing
  • Have fixed ideas and narrow interpretations
  • Place disproportionate importance on habits and routines
  • Have difficulty resolving past problems and remaining traumatised by events from the past
  • Become overly distressed and distracted by minor difficulties encountered en route or just prior to the appointment

Screening and Co-occurring Conditions

This topic will cover the alerting signals for ASD, current screening instruments, co-morbidity and recommendations for practice.  This will be particularly useful to practitioners who are involved in identifying possible ASD and referring individuals for a diagnostic assessment.

Parental Concerns

Parents’ early concerns have usually been around delayed language; lack of appropriate response; deafness; difficulties in engaging and comforting their child when distressed.

Parents have often spent several months and sometimes years concerned about their child and received conflicting (and often upsetting) messages from professionals.

Information that is important to collect includes:

  • The nature and timing of their first concerns.
  • Parents’ current concerns.
  • Professionals seen to date and the views they have expressed.
  • Parental view on the possible reasons for their child’s difficulties.
  • Views of the wider family on the child’s difficulties.
  • Parents’ feelings and views on the advice and support they have had to date.

Alerting Signals

It is important to train all practitioners in alerting signals for a possible ASD. A consensus has developed on the early indicators and alerting signals of ASD (SIGN, 2007).

Early indicators – alerting signals include:

  • No speech or delayed speech.
  • Unusual response to others during interactions.
  • Lack of joint attention and shared interest.
  • Difficult to comfort when upset.
  • Failure to orientate to name.
  • Limited or ineffective attempts to communicate with others.
  • Limited use of gesture, often absence of pointing and limited facial expression.
  • Distressed by unpredictable events.

See Case Study 3 - Young Child Arjinder

NICE Guidelines

Age at diagnosis

The SIGN Guidelines (2007) indicate that minimum age when diagnosis can reliably made is not clear.  Diagnosis can generally be made between 2-3 years old by experienced professionals for those who would have been diagnosed with “autism” under DSM-IV or “childhood autism” in ICD-10.  For those who are identified later as having ASD the early features (before two years old) may have been non-specific. The average age at diagnosis varies between authorities/areas and is often much later for those with Asperger syndrome and high functioning autism. 

Early diagnosis is desirable because:

  • Appropriate intervention can start early.
  • Parents spend less time not knowing the reason for the child’s behaviour.
  • Other family members can understand and be more supportive.
  • Parents can give appropriate support at home.
  • Professionals involved with the child can understand the child and take relevant action.

Identifying "able" children and adults with ASD

For individuals where there have not been early concerns about development (such as language delay) ASD might be more difficult to recognise.  These individuals might find it harder to obtain a diagnosis as they have the cognitive and verbal skills to mask their difficulties. They may have high levels of skill in certain areas relative to peers. However their self help and organisational skills may be very much lower than one would expect of a typically developing individual.

The term high functioning autism (HFA) can mislead parent/carers and others. The developmental profile in ASD is often much more uneven than in the typically developing person so that one should not assume high levels of skill across all areas.

For the able child or adult with ASD, information on the following areas is useful:

  • Nature of conversational skills and topics.
  • Social and pragmatic uses of language (including body language; intonation; volume; eye contact).
  • Reasons for communication with others.
  • Activities pursued in ‘free time’ - both indoors and outside – with and without others.
  • Nature of particular skills or interests.
  • History of social interaction and responses.
  • Functional level of daily living skills relative to intellectual ability (e.g. shopping; crossing roads; cooking, personal hygiene).

Screening Instruments

There is as yet, no reliable screening test for ASD. Attempts have been made to devise such a test, the most commonly known being the CHAT (Baron-Cohen et al. 2000).

  • The CHAT (Checklist for Autism in Toddlers)  comprises nine items completed by parent interview and five items completed from structured observation in the clinic or home for children aged between 18 months and 36 months. It has been used to train primary care workers in the alerting signs for ASDs in some areas.
  • A modified and expanded version of the CHAT – the M-CHAT (Robins et al., 2001) has been developed.
  • The CAST (Childhood Autism Spectrum Test formerly known as Childhood Asperger Syndrome Test) (Scott et al., 2002) has been developed for use with primary school aged children. Allison et al (2007) report on the test-retest reliability of the CAST and indicate that it can be used as a screening test in epidemiological studies but not as a population screening test.
  • (NAPC 2003) does not recommend whole population screening for ASD as there is as yet no sufficiently reliable instrument for this.

Population screening for ASD is not recommended within the SIGN guidelines or by the UK National Screening Committee (2012). Within Scotland following the Health for All Children review (referred to as Hall 4) it was recommended that there is a universal Child Health Surveillance programme. Concerns may therefore be identified by practioners during routine developmental checks. The NICE guidelines provide useful information on when to consider the possibility of ASD and to refer on for assessment.


This topic will cover the main criteria for a diagnosis of ASD, its causation, the potential benefits of diagnosis and current good practice relating to identification and diagnostic assessment.

Diagnostic Criteria For ASD

Different levels of autism awareness required – surgery receptionist should know how to handle ‘different’ behaviour, but take it no further; GP should know how to suggest referral for a formal diagnosisThe two main diagnostic systems used within the UK are the International Classification of Diseases (ICD-10) and Diagnostic and Statistical Manual of Mental Disorder (DSM-5).  Although there is similarity in the signs and symptoms described within these there are differences in the structure of the criteria and the use of subgroups.

Within ICD-10 the diagnostic criteria are grouped into three areas (social interaction, communication, repetitive interests, activities and behaviours). This is commonly referred to as the “triad of impairments”.  DSM 5 no longer separates signs and symptoms of ASD into three areas and instead uses the dyad of “social communication and interaction” and “restricted, repetitive patterns of behaviour, interests or activities”

Using ICD-10 the possible diagnostic categories fall within pervasive developmental disorders and are:

  • Childhood Autism
  • Atypical Autism
  • Asperger’s Syndrome

In DSM 5 the term “Autism Spectrum Disorder” is now used to include all of those who have a diagnosis falling within the autism spectrum. 

DSM 5 Diagnostic Criteria

Sometimes identifying ASC features may merely require a change in practice; other times, it may require discussion with a manager or supervisor regarding possible action, such as onward referralA. Persistent deficits in social communication and social interaction across multiple contexts, as manifested by the following, currently or by history (examples are illustrative, not exhaustive, see text):

  1. Deficits in social-emotional reciprocity, ranging, for example, from abnormal social approach and failure of normal back-and-forth conversation; to reduced sharing of interests, emotions, or affect; to failure to initiate or respond to social interactions.
  2. Deficits in nonverbal communicative behaviors used for social interaction, ranging, for example, from poorly integrated verbal and nonverbal communication; to abnormalities in eye contact and body language or deficits in understanding and use of gestures; to a total lack of facial expressions and nonverbal communication.
  3. Deficits in developing, maintaining, and understanding relationships, ranging, for example, from difficulties adjusting behavior to suit various social contexts; to difficulties in sharing imaginative play or in making friends; to absence of interest in peers.

B. Restricted, repetitive patterns of behavior, interests, or activities, as manifested by at least two of the following, currently or by history (examples are illustrative, not exhaustive; see text):

  1. Stereotyped or repetitive motor movements, use of objects, or speech (e.g., simple motor stereotypies, lining up toys or flipping objects, echolalia, idiosyncratic phrases).
  2. Insistence on sameness, inflexible adherence to routines, or ritualized patterns or verbal nonverbal behavior (e.g., extreme distress at small changes, difficulties with transitions, rigid thinking patterns, greeting rituals, need to take same route or eat food every day).
  3. Highly restricted, fixated interests that are abnormal in intensity or focus (e.g, strong attachment to or preoccupation with unusual objects, excessively circumscribed or perseverative interest).
  4. Hyper- or hyporeactivity to sensory input or unusual interests in sensory aspects of the environment (e.g., apparent indifference to pain/temperature, adverse response to specific sounds or textures, excessive smelling or touching of objects, visual fascination with lights or movement).

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.

Causation and Onset

ASD has a genetic and organic basis and cannot be caused by inadequate or negligent parenting.

Research suggests that early trauma, neglect and abuse does not cause ASD, but extreme neglect may lead to quasi-autism in some, which disappears when conditions become more conducive (Rutter et al.1999). Further information on differentiating between ASD and Attachment Disorder is available (Moran, 2010).

The needs of parents

  • Understand that women and girls present differently and that females currently under diagnosed Despite this evidence, parents are still often blamed for their child’s apparent anti-social and difficult behaviour BEFORE diagnosis. This can make them angry and mistrustful of practitioners. See Case Study2: Older Child Sam.
  • Parents often see many practitioners and may have received conflicting views and advice on the child’s difficulties.
  • Practitioners need to explore what the parents have already been told and how they feel about previous consultations.
  • Practitioners need to ask parents to give their views on possible reasons for their child’s difficulties.
  • It is vital to listen to the parents and trust their accounts.

There is strong evidence for the heritability of ASD and an increased risk that siblings and the parents of children with ASD will also have ASD, or a milder variant or broader phenotype.

The needs of parents

  • The parents themselves may have difficulty in some aspects of the consultation process (e.g. attending to what is said; processing rapid spoken information). Giving written back-up information might help.
  • A series of short consultations is preferable to a long session because of the problems in retaining information in a stressful situation.

ASD persists into adulthood. It may be harder to detect the condition in later life, as adults have developed skills and learned strategies to manage or avoid situations they find difficult.

  • Taking a detailed history from the parent/carer and the individual him or herself where possible and reading past reports, if available, are vital sources of information in the diagnostic process.

Diagnostic Assessment Process

The diagnostic process varies throughout Scotland and the UK with local areas having their own processes in relation to who is involved in making a diagnosis and what happens at each stage.  Past attempts to improve consistency include the publication of the National Autism Plan for Children (NAPC) in 2003 (NIASA).  There are also Scottish Intercollegate Guidelines Network (SIGN) guidelines on " Assessment, Diagnosis and Clinical Interventions for Children and Young People with Autism Spectrum Disorders " (SIGN 2007) and more recent NICE guidelines on Assessment and Diagnosis in Children (2011) and Adults (2012).  Autism Network Scotland host a list of all services in Scotland that provide diagnostic assessment and links to information from the Autism Achieve Alliance review of waiting times for assessment.

Key recommendations on diagnosis from SIGN 98 and the NIASA report are as follows:

  • Reports on current functioning should be obtained from those who know the individual and the family.
  • An assessment of the needs and strengths of the individual and the family should be made.
  • In addition to information on the three core areas of ASD, an assessment of unusual sensory responses (Bogdashina, 2003), motor planning and coordination difficulties and self-care skills is needed.
  • Information should be obtained across settings and disciplines
  • A detailed developmental and family history should be taken by practitioners experienced in ASD.
  • The individual should be observed in different, natural settings, including the home, if possible.

 ASD affects many areas of development and is classified as a Pervasive Developmental Disorder. To gain a comprehensive profile of the individual with ASD, it is vital to obtain the views of professionals working within and across agencies who know the individual well.

Focused observations across settings, should involve observing the individual interacting with others including parent/carer, unfamiliar adults, siblings and peers.

Communication and social interaction need to be assessed in terms of the frequency and type of contact initiated with others and their response to others.

Primary care practitioners may not be involved in full diagnostic assessment but will need to gather related information in order to refer for further investigation, where this is appropriate. Where possible information should be gathered about the following to include in referrals for consideration of ASD.  

Observe or ask about:

  • Play/leisure activities when the individual is alone
  • Nature and frequency of interaction with siblings and peers at home and school/workplace
  • Nature and frequency of interaction with parents and familiar adults with and without toys/materials
  • Response to structured play/tasks set up specifically for assessment purposes (Autism Diagnostic Observation Schedule ADOS: Lord at al 1994)
  • Reaction to visual stimuli and lighting, sounds, touch, taste and smell using a checklist such as that devised by Bogdashina (2003).
  • Diagnostic process – medical tests. There are a number of conditions, which appear to be associated with ASD and specific testing or assessment may be required
  • NIASA recommends that, as part of a full diagnostic procedure, practitioners routinely carry out chromosomal karyotyping including fragile X DNA analysis, assess for the possibity of epilepsy and check their sensory responses and motor coordination. Primary care practitioners should be aware of the relevance of these likely investigations and be able to discuss them with parent/carers or the individuals with ASD themselves.

Diagnosis of adults with ASD

There are many adults with ASD who have not been diagnosed because there was less expertise in ASD when they were children or their skills masked their problems. See Case study: Adult William.

Some of these adults may not require, or benefit from, an official diagnosis or intervention as they are able to manage their lives without such support.

However, there will be others who have not yet been diagnosed or who have had a late diagnosis of with ASD.  They are more likely to have experienced significant problems with daily living, employment and relationships with family and others. This increases vulnerability to developing mental health disorders (see biographies by Lawson (2003), Sainsbury (2000) and Gerland (1997)).

There are a number of reasons why there are currently many adults with ASD who have not yet been diagnosed or who are late diagnosed. These are as follows:

  • Their skills, particularly in spoken language and academic achievements have helped masked their difficulties.
  • When they were children, there were far fewer professionals who had experience in ASD.
  • Taking a good and reliable developmental history on an adult may be difficult unless good written records exist or the parent/carer or patient is able to recall early events.
  • Other explanations were given to account for their behaviour or difficulties (e.g. depression; schizophrenia; agoraphobia, personality disorder or other disorders such as bipolar disorder were thought to be a sufficient explanation).
  • There are fewer specialists in adult services who have experience in diagnosing ASD.

Diagnostic Instruments

As yet, there is no biological, medical or psychological test, which can confirm the diagnosis. Diagnosis is made on the basis of taking a detailed developmental history and observing the individual in a number of different settings (both natural and clinic settings).

Diagnostic instruments have been developed to help practitioners know which questions to ask in relation to the main diagnostic criteria. Specific training to use these is required and is restricted to certain professional groups.

Diagnostic instruments designed to obtain a good developmental history include:

Observation of the individual

Diagnostic instruments designed to help practitioners know what to observe and record have been developed.  The most commonly used is the Autism Diagnostic Observation Schedule (ADOS) which was updated in 2012 (ADOS-2).

Benefits And Risks Of Diagnosis

This section covers the potential benefits of diagnosis to the individual and the family, but also explores some of the risks and current issues surrounding diagnosis.

Potential benefits of diagnosis to the individual with an ASD

"The ASC diagnosis is not the end point- expectations of skill development is an ongoing process. ASC should not be disempowering and people should not diminish what people can achieve."

  • Individual may experience relief after diagnosis, but this may be short-termHelps individual understand source of own difficulties and identify possible strengths.
  • Guides appropriate intervention
  • Alerts all professionals involved, to the particular needs of the individual and family
  • Gives parent/carers access to specific ASD literature, support groups and other parent/carers
  • Helps in decisions about provision
  • May give access to financial allowances
  • Enables those who are able to read about ASD and therefore may develop an understanding of the difficulties they have.
  • Parents/carers not blamed for their child’s behaviour and may get support from family and professionals.

There are a number of benefits of diagnosis for professionals and parent/carers as well as for the individual concerned.

Potential benefits of diagnosis to the parent/carers of individuals with ASD

  • For some an autism diagnosis can be a relief, but for others it can damage confidence, etc.Aids understanding of the behaviour of their  son/daughter and enables access to sources of help for difficulties
  • Alerts all professionals involved to the particular needs of the individual and family
  • Gives parent/carers access to specific ASD literature, support groups and other parent/carers
  • Helps in decisions about educational/living provision and career choice
  • May give access to financial allowances to support in daily living, in further and higher education
  • May gives access to employment support schemes
  • May gives access to more suitable housing or living provision.

There are a number of benefits of diagnosis to the adult with an ASD.

Potential benefits of diagnosis to the adult with ASD:

  • It allows adults to make sense of themselves and their experiences.
  • Other people’s responses might alter for the better once the diagnosis shared.
  • It can enable the adult to access the literature and support groups and develop an understanding of ASD and their own difficulties and strengths
  • It can enable the adult to develop strategies to address his/her own problems.
  • It may give access to ASD specific Internet sites to access information and to allow discussion with others.

Self esteem may be enhanced by meeting, reading about and emailing successful people with ASD.

Post Diagnosis

This topic will cover practice following diagnosis including written reports, sharing the diagnosis and recommendations for intervention.

“Recognising older people who may not have a diagnosis especially women and how they are supported to not 'fall through the cracks'”

Diagnostic Reports

Diagnostic report – terminology

In terms of terminology it is advisable to avoid the use of terms such as ‘autistic traits‘, ‘autistic features’ and ‘autistic tendencies’ in reports as there is no behaviour or trait, which is of itself unique to ASD.

Diagnosis is based on a particular combination of behaviours, which occur together, so the term autism should not be used unless all the criteria for a diagnosis are met.

Important components of a diagnostic report are:

  • A statement about the nature of the evidence on which the diagnosis was made.
  • Comment on the certainty of diagnosis and any contra-indications to an ASD.
  • A clear explanation of ASD using examples of the individual’s behaviour to illustrate the point.
  • Information on early development and current functioning.
  • Results of test scores with explanation given as to their value.
  • Areas of strength and special interests.
  • Areas of development, which need intervention, both related to core difficulties and in other areas.
  • Advice on how to support the individual and their family/carers at home and elsewhere.
  • References to the literature on ASD.
  • Information on local support services.
  • Parents’ views on diagnosis and the report.
  • List of those who have been sent a copy of the report (agreed with client/parent/carers).

Sharing a Diagnosis With Parents/Carers

Sharing the diagnosis with the parents is a highly skilled and sensitive task.

Practice varies across the UK in terms of how this is done and by whom.

This task will not usually be the responsibility of primary health care professionals, although they may be the first to suspect an ASD diagnosis and may be asked to comment on issues relating to diagnosis.

Good practice is that where practitioners discuss:

  • When to give the diagnosis
  • Where to give the diagnosis
  • Which family members or friends should be present
  • Which person(s) is best to deliver the information
  • The spoken and written information that will be given
  • How and when the first session will be followed up

However, it is NOT good practice to deny access to a diagnosis to the parents/carers or the individual (where appropriate) when that diagnosis has been made. If the diagnosis is uncertain, that uncertainty should also be shared, together with the steps to be taken to help achieve a firm conclusion.

Recommendations On Interventions

The main purpose of diagnosis is to guide decisions on how best to support the child or adult. Recommendations should therefore be suggested at the time of diagnosis and a section included in this within the diagnostic report.

NIASA recommends that intervention should follow within 6 weeks of the diagnosis being given to the family - (2003).

Clearly, professionals from health, education, social services and the voluntary sector need to work together to discuss the following:

  • Which services need to be involved in making recommendations to support the family?
  • To which individual should the diagnostic report be sent?
  • Would it be useful to appoint a keyworker to coordinate the work, and if so, who should this be?
  • Who will check that the recommendations are carried out?

There is great variation within the population of those diagnosed with an ASD depending on intellectual ability and the co-occurrence of other conditions. Reviews of research suggest that an individual with ASD will benefit from a number of different services and interventions and that these will differ between individuals and over time.

Not all children or adults will benefit from the same interventions or type of intervention as there is great diversity within the ASD population. Those involved with the individual and the family need to make an assessment of what interventions are likely to help develop skills and understandings and which services might deliver these.

To summarise:

  • Individuals with ASD differ from each other and so will need different types of intervention.
  • Parents and families differ in terms of what they would find useful or what they are able to access or take up.
  • A service should therefore be able to offer a range of approaches to both the individual with ASD and the family.
  • A priority goal for young children should be to enable both child and parents to interact successfully.

A consensus is developing from reviews of research on the key elements and goals of successful and effective interventions.

Identifying the key components of programmes and services which seem to be effective is very helpful in evaluating practice and guiding interventions.

It is important to recognise that failure to provide timely and appropriate interventions for children with ASD post diagnosis, leaves parents vulnerable to ‘advertisements’ for expensive (and often untested) interventions on the Internet.

Key components of interventions which are effective in ASD include:

  • Early intervention following diagnosis
  • Parental involvement
  • Recognising the sensory issues for the individual
  • Structure and predictable activities and timetables over 24 hours
  • Including relaxation opportunities
  • Having clear communication systems for all
  • A functional approach to behaviour and the teaching of acceptable alternatives
  • Supporting transitions
  • Physical exercise (aerobic)
  • Those which highlight the strengths and interests of the individual
  • Those where staff and parents discuss and monitor the effects of intervention.

Diagnostic Issues

Diagnostic Criteria and Subgroups

As previously described there are two main diagnostic systems used within the UK when considering a diagnosis of Autism Spectrum Disorder.  These are the Diagnostic and Statistical Manual of Mental Disorders (DSM) and the International Classification of Disease (ICD).  The most recent version of DSM, DSM 5 was published in 2013 and there were considerable changes to the structure of the diagnostic criteria such that the previous subgroups were removed and the diagnosis now given is “Autism Spectrum Disorder”.  The list below describes the subgroups that exist in ICD-10 and existed in the DSM-IV:

  • Asperger syndrome
  • High functioning autism
  • Autism
  • Pervasive developmental disorder – not otherwise specified
  • Childhood disintegrative disorder

There is continuing debate about whether it is helpful to classify into subgroups and whether there are more similarities than differences in these.  It is often difficult to neatly define subgroups in ASD (e.g. Kanner’s autism; Asperger syndrome; high functioning autism (HFA)) as there is considerable overlap between these groups. Diagnosis relies on observation and parental and professional report.  A recent review of this issue highlights the balance diagnostic systems seek between being too narrow or too broad and the additional issue that some of those who may meet the diagnostic criteria for ASD may view this more as a personality type than a disorder (Volkmar and McPartland, 2014).

Asperger Syndrome

The term Asperger syndrome (AS) was introduced by Wing (1981) to the English speaking world, to highlight the needs of able people with autism (based on the work of Asperger with this group) and was viewed as the able end of the autistic spectrum. Since then, some have suggested that those with AS are different in other ways to those with autism.

There was ongoing debate about the defining criteria for this condition since the inclusion of the diagnosis of Asperger’s disorder in DSM-IV in 1994. One of the main changes to the structure of the diagnostic criteria within DSM 5 is the removal of the diagnosis of Asperger Syndrome.  Clinicians using the DSM criteria can no longer give a diagnosis of Asperger Syndrome using this diagnostic system and would instead diagnosis “Autism Spectrum Disorder”.  However, a diagnosis of Asperger Syndrome can still be given when using the ICD-10 diagnostic system.

There is an increasing weight of opinion that Asperger syndrome should be reframed as a socially constructed human difference rather than as a medical condition or mental disorder (Allred, 2009; Molloy et al., 2002).

A key question is how those with Asperger syndrome differ from individuals with autism who are of average or above intellectual ability, often referred to as those with High Functioning Autism (HFA). The main distinction made in the diagnostic criteria (ICD-10) is that those with Asperger syndrome are not delayed in developing spoken language, unlike those with autism. By the age of 5 or 6 years of age however, the speech and language of children with Asperger syndrome and those with autism may be fairly similar and so the question then becomes – are there remaining differences that warrant a separate diagnostic category? Szatmari et al. (2009) sought to look at whether there was a difference between the developmental trajectories or outcomes of children with AS and those with HFA. In a sample of 64 children, they concluded that there were differences in outcome in that by late adolescence, those with AS had higher levels of adaptive functioning and fewer autistic symptoms than the HFA group, but that both groups improved roughly at the same rate.

Screening and diagnostic tools have been created to identify and diagnose this group including the CAST (Childhood Asperger Syndrome Test), the Adult Asperger Assessment (AAA), the Autism Spectrum quotient and the ASDI (Asperger Syndrome Diagnostic Interview) as other instruments developed to identify autism appeared to miss some individuals with Asperger syndrome. These involve observation and/or interviews with parents or carers or the patient him or herself.

Some of the key differences that are thought to exist between those with autism and those with Asperger syndrome, are as follows:

  • Those with AS are more socially interested.
  • Those with AS are more aware of their difficulties and keen to be like their typical peers.
  • Those with AS are more likely to develop mental health difficulties (McPartland and Klin, 2006).
  • Those with AS are more likely to be clumsy.

The term ‘high functioning autism’ has been criticised by adults with this diagnosis as it implies they are more able than is actually the case, leading other people to assume they are able to perform tasks, which are beyond their ability. This is particularly so if there is a social element in the task or it involves multi-tasking.

Differential Diagnosis

Misdiagnosis and over-diagnosis

Differentiating an ASD from other disorders can be complex, where the child has additional disorders or where there has been early childhood trauma. Many children in the first few years of life experience communication and social difficulties but do not have an ASD.

Children who might be incorrectly diagnosed or suspected of having an ASD are those:

  • In care or those who have experienced separation and emotional and psychological abuse may appear to have an ASD. Many will not have an ASD but there will be some in this group who do.  Moran (2010) reports the Coventry Grid which describes clinical observations of the differences between those with ASD and attachment disorder.
  • With ADHD or emotional and behavioural problems.
  • With other speech and language disorders who may have a similar profile of difficulties in the early years, although they are usually socially more skilled.
  • With delayed development or unusual behaviours.
  • With visual or hearing impairments.

However, it is also essential to recognise that there are high rates of co morbidity between ASD and other conditions (Simonoff et al, 2008)

Misdiagnosis and Missed diagnosis

Adult biographies of those with ASD frequently refer to misdiagnosis (e.g. Lawson, 2001; Sainsbury, 2000; Aston, 2000).

Mental health disorders such as schizophrenia or OCD may have been diagnosed incorrectly and antipsychotic medication prescribed. This is often because of the way in which adults with ASD respond to events and situations and the responses they give to questions about their mental state and experiences. These misunderstandings may occur because of the literal use of language, echolalia and the use of the affirmative to shorten the interaction (Howlin 2003).

In the following situations the diagnosis of ASD might be missed:

  • Behaviour may be misinterpreted and may be labelled as naughty, anti-social, lazy, rude or deviant.
  • In children with severe learning difficulties, Downs syndrome, visual, hearing or physical impairment.
  • In children who have had abusive or traumatic early experiences as their social and communication problems are thought to stem from those experiences rather than ASD.
  • In children for whom English is not their first language.


There is a danger that once ASD has been diagnosed, that this is viewed as the primary cause of behaviours seen and further diagnoses of other conditions may be overlooked and vice versa.
It is possible for an individual to have an ASD together with any other condition.

Other conditions which can co-occur with ASD and which seem to be more prevalent in ASD than in the typical population are:

  • Epilepsy
  • Intellectual disability
  • Dyslexia and hyperlexia
  • Dyspraxia/developmental co-ordination disorder
  • Depression
  • Chronic anxiety

Clearly it is also possible for an individual with ASD to have any other condition in addition to ASD, including:

  • ADHD
  • Cerebral palsy
  • Downs syndrome
  • Sensory impairment
  • Mental health disorders

Mental Health Issues

Practitioners need to check for evidence of mental health disorders, particularly depression, anxiety and OCD. Depression and anxiety are likely to be more common in the ASD population due to the nature of their social and communication difficulties, but much can be done to prevent such conditions by providing appropriate and supported environments at home, school and in employment . (Ghazuiddin 2005)

Individuals with ASD can have difficulty expressing their feelings and emotions using speech. It can be difficult to differentiate behaviours due to ASD from those which may underpin anxiety or clinical depression. This can make diagnosis of mental heal disorders difficult.

It is important to:

  • Involve all who know the individual well in the assessment.
  • Obtain a history of the behaviours.
  • Determine the contribution of the past or current stresses on the condition.
  • Select the least restrictive intervention to address the condition.

Females and ASD

In the past, a number of prevalence studies suggested that there were four times as many males as females on the autism spectrum (Fombonne, 1999) rising to 8:1 or 9:1 in the intellectually able group (Lord et al.,1982). However, many involved in the field now think this ratio is inaccurate and that there are more females with the condition than was previously thought. Fombonne (2003) has suggested a ratio of 3:1.

A population study of 6,176 individuals with ASD by Rosenberg et al. (2009) found there was a significant gender difference in mean age of diagnosis, with females more likely to be diagnosed at a later age and less likely to be given a diagnosis of Asperger syndrome. They found that many factors other than the patient’s actual signs and symptoms influenced the diagnosis made. It is argued that females with ASD might present differently from males and so may not be recognised as having a difficulty or they may be misdiagnosed as having a social, emotional or behavioural disorder or a psychiatric disorder. It is also thought that about a fifth of females with eating disorders particularly anorexia may be on the autism spectrum. Some of the gender differences may, as in typical children, be caused by socialisation, gender-role models and different child-rearing practices (Holtmann et al., 2007). More research is needed to refine methods to analyse gender differences in ASD more effectively.

When a female patient presents with a history of difficulties in social understanding or with anxieties about friendships, and with an unusual or intense communication style and rigidity of thinking or behaviour, consider referral to a multi-disciplinary team for a full diagnostic assessment.

Currently, ways in which it is thought that females might differ from males with ASD are as follows:

  • Females may be better at masking their difficulties to fit in with their peers.
  • Females may be more socially interested and concerned about their lack of friendships.
  • Females may be more likely to have special interests with a social element (e.g. fashion; an interest in a TV or sporting personality).
  • Females may be more passive than boys with autism and so viewed as just shy.
  • Females may have better language skills than males and so go unrecognised.
  • Females may have greater social difficulties with peers during adolescence (McLennan et al., 1993).
  • Females may have more difficulties with attention, impulsivity and executive functioning (Holtmann et al., 2007).
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