Autism Diagnostic Services


More about ATPlus diagnostic services

Autism Spectrum Disorders
Autism is a lifelong developmental condition that affects how individuals communicate with and relate to other people and the world around them. It is often referred to as an Autism Spectrum Disorder (ASD) or Autism Spectrum Condition (ASC). For the purposes of this document the term Autism and ASD are used interchangeably, whilst Asperger Syndrome (AS) or High Functioning Autism (HFA) is used to refer to individuals at the higher functioning end of the Autism Spectrum. Autism touches individuals in many different ways, although people with ASD will experience difficulties in two main areas: social communication and behaviour.

Social Communication

Social Communication refers to the use and understanding of language as well as non- verbal communication, such as eye contact, gestures and facial expressions. Difficulties experienced by people with an ASD in this area vary. At one end of the spectrum, people may have no speech or limited verbal skills, but their understanding of language may not be equally affected. At the other end of the spectrum, individuals are able to speak with minimal grammatical errors, but their understanding of communication might be impaired. There is not necessarily a link between the expressive and receptive skills of a person with ASD, recognising this and not judging an individual’s skills solely on their verbal ability can help ensure they receive the appropriate support to help them communicate.

Children and adults with autism have difficulties with everyday social interaction, they may have difficulties in establishing and maintaining social relationships, understanding other people’s emotional expression and expressing their own emotions which can make it more difficult for them to fit in socially. The learning and social demands of a school or work environment can be challenging. This can impact on their ability to recognise and understand other people’s thoughts and feelings and therefore affects how they relate to and interact with others. Some difficulties can be more subtle, for example the ability to understand the social code of one’s peers, and may result in bullying and/or social exclusion.

Behaviour & Sensory Processing
People with an ASD may have difficulties processing sensory information in one or more of the five senses, such as sounds, smells or touch. They may be hypersensitive to certain sounds; they may cover their ears, move away from busy and noisy places, or demonstrate challenging behaviours. They may have a limited range of interests and have difficulty coping with transition, and as such may feel more comfortable with a fixed daily routine. Often people with ASD have an intense interest in a particular area, such as dinosaurs, train time tables, drawing, or computers and it is important to capitalise on these specialised areas of interest to help individuals feel respected and valued.

A person’s social communication skills and behavioural problems can be assessed using the Social Communication Questionnaire (SCQ), the Vineland scale and the Social Responsiveness Scale 2 (SRS-2). These tools are very informative in reaching an opinion on a possible ASD diagnosis but they are insufficient to reach a full diagnosis. For a full diagnosis, an ADOS and sometimes an ADI-R assessments are needed. More information about these tools is included below.


Autism Spectrum Disorder Diagnostic Assessment
The diagnostic assessments offered at Autism Treatment Plus are based on several standardised diagnostic protocols designed to identify individuals with autism. These include the Autism Diagnostic Observational Schedule (ADOS)- 2 which comprises direct observations of the child or adult and the Autism Diagnosis Interview-Revised (ADI-R), which is an in depth interview with parents to cover the full developmental history of the individual.  The ADI-R might not be required if a diagnosis can be reached using the ADOS-2. We also use a series of complementary questionnaires, Vineland, SRS-2 and SCQ described below. These alone are not sufficient to reach a diagnosis but offer very detailed information about the social, communication and behavioural difficulties experienced by the person. This will be sufficient to issue a detailed report to request the NHS to carry out a full diagnostic assessment, sometimes, that is all that is needed to progress a person on a diagnosis pathway. Enclosed below is more information about each of the assessments and costing.

ADOS-2 (Autism Diagnostic Observation Schedule)

The ADOS assessment is a semi-structured standardised assessment designed to assist in the diagnosis of autism spectrum disorders. The tool allows the evaluation of a person’s communication, social interaction, play and imaginative use of material under set contingencies. There are 4 modules available, based on the person’s age and level of communication. Each module takes 45-60 minutes to administer. As the module level increases, the assessments include progressively more challenging tasks, in order to highlight the autistic features the person may have. This is achieved through planned social occasions, referred as “presses”, in which the behaviour of a particular type is more likely to occur. The assessment is very detailed and includes a large range of verbal and nonverbal communication and language skills as well as behaviours.

ADI-R (Autism Diagnostic Observation Schedule- Revised)
The Autism Diagnostic Interview- Revised (ADI-R) is an interview evaluation of individuals with a suspected autism spectrum disorder used as an aid to formal diagnosis. The tool has proven effectiveness in differentiating autism from other developmental disorders, assessing syndrome boundaries, identifying new sub-groups and quantifying autistic symptomatology.

The interview covers 93 items grouped into three functional domains:

Language and Communication
Reciprocal Social Interactions
Restricted Repetitive and Stereotyped Behaviours and Interests and covers eight content areas:

The subject’s background including family, education, previous diagnoses and medication
Overview of the subjects behaviour
Early development and development milestones
Language acquisition and loss of language or other skills
Current functioning in regard to language and communication
Social development and play
Interests and behaviours
Clinically relevant behaviours such as aggression, self injury and possible epileptic features

The Vineland Adaptive Behavior Scales, Second Edition (Vineland)
The Vineland questionnaire is a well-known assessment of daily living skills that is commonly used in educational, clinical and research setting. The scales measure four broad adaptive behaviour domains: Communication, Daily Living Skills, Socialisation and Motor Skills. It is administered through interviews or a rating scale for parents/caregivers and teachers. The four domain composite scores have all been standardised with a mean of 100 and a standard deviation of 15. The scales have been used to evaluate a range of disorders and disabilities such as mental retardation, Down Syndrome, ASD and other developmental delays. The Vineland scales have been found to be of benefit to improve ASD diagnosis accuracy, especially when the ADI-R and ADOS scores are not congruent. It is also of some use to follow the longitudinal progression of individuals across their lifespan.


Social Communication Questionnaire (SCQ)

The SCQ is a 40-item questionnaire derived from the Autism Diagnostic Interview-Revised (ADI-R) (Constantino et al., 2003). It offers two algorithms, a lifetime diagnosis, which refers to the behaviour throughout the child’s lifetime and a current algorithm, which focuses on the most recent 3-month period. It has a good discriminative validity with respect to the separation between ASD and non-ASD children across all IQ levels. The lifetime SCQ cannot assist in measuring the level of autism of the children at the time of the assessments, as it refers to specific periods of the child’s life and whether or not he has ever displayed such and such behaviour; for example, presented with special interests that were unusual in their intensity or, had ever had any mannerism or odd ways of moving his/her hands or fingers. This version of the SCQ however will be of help in judging a child’s progression.

The SCQ sub-domains were found to have good correlation coefficient with the ADI-R sub-domains ranging from 0.73 to 0.89.

A cut-off score of 15 is recommended on the Lifetime SCQ as an indication of a possible ASD. The general population was found to have a mean value of 5.2, whilst the mean score for children with autism was 24.2 (Berument et al., 1999). Individuals scoring around 10-11, well above the general population mean, but below the cut-off point for a possible ASD, should be referred for more complete diagnostic evaluation.


Social Responsiveness Scale -2 (SRS-2)
The second edition of this highly regarded autism assessment offers the convenience of a screener and the power of a diagnostic tool. The SRS-2 identifies social impairment associated with autism spectrum disorders (ASDs) and quantifies its severity. It is sensitive enough to detect even subtle symptoms, yet specific enough to differentiate clinical groups, both within the autism spectrum and between ASD and other disorders. And, with an expanded age range, the SRS-2 can be used to monitor symptoms throughout the lifespan.

In addition to a total score reflecting severity of social deficits in the autism spectrum, the SRS-2 generates scores for five Treatment Subscales:

Social Awareness (Awr)

Social Cognition (Cog)

Social Communication (Com)

Social Motivation (Mot)

Restricted Interests and Repetitive Behaviour (RRB)

Although not used for screening or diagnosis, subscale scores are helpful in designing and evaluating treatment programs. 

Similarly, the SRS-2 unlimited-use scoring program gives a detailed report with useful descriptive information that can inform intervention.

The SRS-2 is supported by a multitude of independent, peer- reviewed studies conducted in schools and clinics throughout the world, involving diverse populations and diagnostic groups. These studies show that the SRS-2 discriminates both within the autism spectrum and between ASD and other disorders–which makes the test highly useful for differential diagnosis. When the SRS-2 reveals social deficits associated with autism, it tells you exactly where these symptoms fall on the spectrum. And when the test indicates that autism is not present, it often points to other conditions in which social impairment plays a role.