Has the broadening of the term Autistic spectrum Disorder (ASD) gone too far?

A retired psychologist’s view of today’s interpretation of ASD

Sally Goddard Blythe MSc.(Psych)

Leading expert on Autism, Professor Dame Uta Frith whose pioneering research shaped our modern understanding of autism in the 1960’s and ‘70’s has recently warned that the spectrum may have become too broad, risking a misunderstanding of patients’ needs.  She has recommended that the spectrum should be “split up” to prevent misdiagnosis[1].

Why is this important?

Mis or over-diagnosis fails to provide a map to understand underlying factors or mechanisms involved in Autistic Spectrum Disorders (ASD) only offering a description of presenting symptoms.  If treatment, therapy or education are to be effective, it is essential to understand what underlies specific behaviours, which ones may be responsive to intervention and which are likely to remain stable over time.

The current diagnostic system relies chiefly on a series of check lists involving developmental history, observations of play and interaction, reports provided by other professionals involved in a child’s care, possible cross-over to other conditions such as ADHD (comorbidity) and ruling out of any medical condition. The broadening of the definition of ASD has shifted diagnosis from a narrow group of severe childhood conditions to a wider spectrum encompassing milder traits, “masking” and adult diagnosis.  While broadening of the spectrum has improved awareness of subtler traits, public awareness and reduced isolation, in the absence of more detailed investigations, it does not provide a clear pathway to addressing the needs of the individual child. 

Autism is more than a collection of observable symptoms.  Autistic traits can be present without adding up to ASD.  Traits may by intrinsic or develop as result of physical, emotional or environmental factors (extrinsic).  Intrinsic factors tend to remain stable over time and are less responsive to intervention. 

Examples of some traits  were described many years ago by  psychologist Carl Delacato (1974)[2] as abnormal “sensoryisms” in which the individual was either hyper or hypo sensitive in one or more sensory channel or experienced “white noise” in which sensory information was distorted by interference. Each type of “sensoryism” could present  a different symptom of either withdrawal,  avoidance, blocking out, excessive seeking or inability to process.   He suggested that resulting behaviours were actually a crude attempt at “self-treatment”.

What is Autism?

Autism was originally described by Kanner (1943)[3] in which he identified  three main features – abnormalities of communication, social development and restriction of behaviour and interests – which manifest themselves in consistent patterns of behaviour or clinical features:

Autistic aloneness, characterised by abnormality in social development in which the child is unable to form warm emotional relationships including being able to respond to parental affectionate behaviour by smiling or cuddling or accepting aspects of physical contact.  While  they are more responsive to parents than strangers there is a general lack of interest in other children and little difference in their response towards people and inanimate objects.   Gaze avoidance is considered to a specific feature of this general lack of social reciprocity.

Delay or lack of speech development which is not the result of hearing impairment or other identifiable cause.  In some cases speech starts to develop only to become arrested or regress at about two years of age.  As they develop, some do acquire some useful speech but with variants from what is considered to be normal speech.  Variants include misuse of pronouns and inappropriate repetition of words spoken by others (echolalia).  Some children are talkative but the content of their speech follows a repetitive monologue rather than engaging in conversation.

Cognitive defect can affect non-verbal communication and play, particularly imaginative or creative play.

Obsessive desire for sameness features of which include stereotyped behaviour with extreme anxiety and distress associated with change.  Examples of desire for sameness may range from a limited range of foods to  inability to cope with change of environment

Bizarre behaviour and mannerisms may include excessive spinning of self or objects, hand flapping and twiddling of objects.

Emotional outbursts  may include excessive, apparently unreasonable anger or fear with inability to regulate their reactions.

A retired psychologist’s view

When I first started to work with children presenting with specific learning difficulties in the 1980’s, if a child had previously been diagnosed with Autism, the features described above are the ones I would have expected to see – namely, little or no verbal expressive language, locked into stereotyped behaviours and showing little or no social reciprocity - the prognosis for these children was not good.

Over the last forty years, the spectrum which encompasses Autistic Spectrum Disorder has become so wide, that at one end children with the traditional symptoms of Autism (described above) and children who have minor features of Autism are being placed under the same label.  Professor Frith is correct in saying that this is not helpful in pointing to effective educational needs, intervention and outcomes.

Furthermore, the earlier separate category of Asperger’s Syndrome is now included in ASD.  Whereas one of the features of ASD is impairment in speech and language, children with Asperger’s Syndrome develop reasonable speech and verbal language but tend to be literal in their understanding and use. Impairment is usually present in their understanding and use of non-verbal language.  Non-verbal language is involved in reading the body language of others and adjusting response accordingly, contributing  up to 90% to effective communication.  It is therefore  an essential component of social interaction.  Different parts of the brain are involved in verbal and non-verbal language and yet both disorders are currently placed under the same general label of ASD. In this area alone, the current diagnostic system fails to take brain function into account.

My work focused on examining underlying mechanisms involved in the presentation of ASD and other specific learning difficulties.  The presenting “label” was just the beginning of the journey.  Common denominators in the form of neuromotor immaturity and differences in sensory processing were present in the majority.  The difference in the presentation and severity of these in each individual are crucial to understanding the presenting symptoms. 

For example, many children with a pre-existing diagnosis of ASD exhibited impairment in near-point visual convergence resulting in figure ground effect. Figure ground effect is a principle of perception describing how the human mind splits a scene into a main focus object (the figure) and everything else (the background).  This enables us to focus on a specific element of the environment without being overwhelmed by the whole scene. Poor gaze control and lack of eye contact can be a symptom of impairment in visual convergence.  This is not to say that training visual convergence would change a diagnosis of ASD, but rather that if one element associated with ASD can be improved, related areas of function may also undergo change (improved focus, less overwhelm, better eye contact, more able to read and adapt to changing environments for example).

A similar trait can be present in processing of auditory information.  During the 1990’s there was considerable interest in the possible role of  auditory hyperacusis in the presentation of autistic signs. It was observed that some children diagnosed with ASD were hypersensitive to sound or specific frequencies of sound.  Certainly, some of the children I assessed using pure tone audiometry were able to detect sound frequencies across the language spectrum at a volume of -10 decibels.  A general level of circa +20 decibels is considered normal.  These children experienced the world as if everyone’s television was operating at full volume and many of their behaviours were simply an attempt to cope with intolerable levels of stimulation and to separate background from foreground auditory stimuli.   Possible causes of hyperacusis are multi-factorial, but in some cases, using a gentle form of sound therapy could help to train the protective and discriminatory pathways involved in the perception of sound to function more efficiently.  It worked for some but not others.

Perception - the brain’s interpretation of sensory information – relies on integration of sensory-motor information, a functional process which is the product of cooperation in systems involved in the reception of information (sensory), output (motor) and feedback (proprioception).   Critical to the efficient functioning of these feedback loops is the vestibular or balance system.  Primarily tasked with responding to internal sensations generated by movement of the head, body or the environment to maintain stability through postural control, the vestibular response is linked to centres involved  in the control of eye movements needed to process visual information and arousal. Underlying vestibular dysfunction can affect visual processing resulting in visual overload  in busy or novel environments, impaired cortical categorisation of visual information and triggering increased arousal.  Inappropriate or excessive stimulation of the vestibular system can also elicit physical sensations associated with the experience of anxiety.

Delacato’s observations helped us to understand that behaviour is often an attempt at self-treatment, for example, covering the ears and making sounds to shut out auditory information or spinning to stimulate the vestibular system and occlude external sensory information.  Sometimes described as autisms, such behaviours offer a key to understanding how each behaviour might be better regulated.   Vestibular function  and its relationship to proprioception provides just one example.

The vestibular system reacts to three types  of motion: rotation, pitch and roll.  The effect on arousal depends on which type(s) of motion is involved and the speed of these movements.  As a general principle, rapid motion is arousing and slow motion is calming, but this is not true for everyone.  If a child engages in repetitive and obsessive stimulation of one kind, it may be serving a temporary purpose, but is not improving function.  A different type or speed of stimulation is needed to entrain the system to operate more efficiently.  This is where specialist assessment and supervision is needed.

Occupational Therapists trained in sensory integration techniques originally developed by A Jean Ayres explain that “modulation is the key”.  Each sensory system has a comfortable threshold for stimulation; if that threshold is exceeded then it is possible for another system to dampen it down.  Vestibular and proprioceptive systems should operate in the this way, so that if someone has experienced excessive vestibular stimulation eliciting sensations of dizziness, blurred vision, loss of balance and nausea, deep proprioceptive stimulation such as half press ups on the floor or against a wall can help to modulate the over-stimulated system.  Understanding these mechanisms do not constitute a cure for individual signs of autism, but working with one system can improve integration of function with others affecting much more than the single system that appears to underlie them.

Autism is not merely the sum of its parts.  It is a complex disorder that may involve one or several systems and higher brain function.  Research using trans-cranial analysis has shown that one difference in higher brain function in individuals in autism is functional connectivity.  Areas of the brain that should be in constant conversation are simply not talking to each other. Other research points to the role of the cerebellum beyond its traditional role of regulating aspects of motor output,  acting as a key player in the ability to instinctively predict sudden changes in social cues  or sensory inputs, regulate neural excitation and the establishment of early circuits involving range and novelty of interests and drive for unfamiliar social exploration.

One of the greatest challenges for parents today is accessing help and support for a child they know to be different.  As societies are increasingly driven into seeking and imposing systems to deal with problems, labels are needed to access advice, assessment, recommendations and intervention.  These systems insist that a child must fall into a recognised category and so diagnostic categories, originally designed to understand presenting symptoms and offer effective solutions, become blurred.  The spectrum widens.  Added to this is a trend towards self-diagnosis in adolescents and adults leading to what Professor Frith describes as “lowering of the diagnostic threshold”.

The difference between a child on the severe end of the spectrum, whose symptoms are consistent with those described by Kanner and a child on the mild end, is like the difference in climate between the north pole and the equator.  The needs of each child are different.  If ASD becomes an umbrella term which simply describes a range of symptoms, without examining underlying mechanisms and severity as sub-categories,  then the term runs the risk of failing to provide a firm basis for recommendations, education and intervention in the future. 

References

[1] Frith U, 2026. Autistic spectrum disorder: has it lost its meaning and it leading do misdiagnosis?  Psychological Medicine. 56.

[2] Delacato CH, 1974.  The ultimate stranger.  The autistic child.  Novato. CA.   Academic Therapy.

[3] Kanner L, 1943. Autistic disturbances of affective contact. Nervous Child. 2:217-250.