Autism Spectrum Disorder-(Part One)Its Diagnosis, Co-Morbidity & Differential Diagnosis

“I might hit developmental and societal milestones in a different order than my peers, but I am able to accomplish these small victories on my own time.” Haley Moss

Autism Spectrum Disorder (ASD) is a group of neuro-developmental disabilities that impacts development in two core domains:

1. Social Communication

2. Repetitive patterns of Behaviors/Interests

1. Social Communication

In the area of social communication, individuals impacted by autism have deficits in:

i) Social & Emotional Reciprocity

· Failure of back and forth conversation

· Reduced sharing of interests

· Failure to initiate or respond to social interaction

ii) Deficit in Non-Verbal Communicative Behaviors

· Poor integrated verbal or non-verbal communication

· Abnormalities with eye-contact and body language

· Deficit in the use of non-verbal communication

· Total lack of facial expressions or use of gestures

iii) Developing and maintaining relationship with others

· Difficulty in adjusting behaviors to suit different social situations

· Difficulty in sharing; imaginative play; making friends

· Absence of interest in other people

2. Repetitive patterns of Behaviors/Interests

The individual must express at least two of the following:

i) Repetitive motor movement

· Motor stereotypies

· Rocking

· Hand flapping

· Flipping objects

ii) Use of Objects/Speech

· Echolalia

· Repetitive speech

· Idiosyncratic speech

iii) Inflexibility

· Extreme distress at small changes

· Difficulty with transitions

· Rigid thinking patterns

· Rituals related to greetings

· Insistence on same route

· Insistence on same food choices at each meal

iv) Restricted fixated interests

· Strong attachment to unusual object(s)

· Excessive circumscribed or preservative interests

v) Hypo/Hyper- Reactivity to Sensory Input

· Indifference to pain or temperature

· Adverse response to certain sounds or textures

· Excessive smelling or touching

· Visual fascination

Why is Autism a “Spectrum” Disorder?

Because of the variability of symptoms of expressions, Autism is considered a Spectrum Disorder. Symptoms can range in severity and the amount of support that an individual requires may also vary depending on the severity of symptoms.

Diagnosis of Autism Spectrum Disorder (ASD)

Average age for diagnosis of Autism Spectrum Disorder (ASD) is 4 years while the ideal age should be by 3 years.

Research indicates the earlier the treatment begins, the better will be the outcome.

· Boys are five times more likely to be identified with Autism than that of girls.

· 1 in 42 boys and 1 in 189 girls are identified with ASD.

· Less than 50% are identified by the age 3.

· On average, no diagnosis is made until after age 4.

· Diagnosis can happen as early as age 2 years

How can diagnosis be made?

In the recent i.e. fifth edition of Diagnostic and Statistical Manual (DSM-V) of mental disorders, autism is described in terms of levels of support required. Therefore, there are three levels of diagnosis of autism:

Level 1- Those who are diagnosed at level 1 does require support:

· Verbal, but have difficulty in initiating and sustaining interactions with others

· Decreased interest in interacting with others and their restricted or repetitive behaviors may interfere in one way or the other

Level 2- Someone with level 2 diagnosis may require substantial support.

· Marked deficits in social interactions even with support in place

· Obvious restricted or repetitive behaviors cause distress when interrupted

{The restrictive or repetitive behaviors are obvious to the casual observer and may interfere with functioning in many contexts and gets disturbed or distressed when interrupted or redirected.}

Level 3- Individuals which are diagnosed at this level have:

· Severe deficits in verbal and non-verbal communication

· Require very substantial support

· Very limited initiation and response to social overtures from others

· Restricted and repetitive behaviors interfere with functioning across all contexts

Who can diagnose Autism Spectrum Disorder (ASD)?

Diagnosis is generally made by a trained licensed medical or mental health professional using DSM-V.

For a comprehensive diagnostic evaluation, use:

1. Behavioral Observations

2. Interview with caregivers & providers

3. Medical & Behavioral History

4. Other medical test to rule out certain medical conditions that may cause similar behavioral characteristics

Why do we require medical diagnosis if autism is suspected?

A medical diagnosis may help in determining the course of treatment or required services.

Co-Morbidity or Co-existing Conditions with Autism

According to Simonoff study (2008):

· 70% of individuals with Autism have co-existing condition i.e. “intellectual disability”

· Clinical Anxiety impacts roughly 29% of individuals on ASD

· Attention Deficit Hyper-Activity Disorder (ADHD) impacts roughly around 28% of autistic individuals

· Oppositional-Defiant Disorder impacts around 28% of individuals on ASD

Differential Diagnosis

Following are the syndromes or disorders that display similar symptom(s) to those of autism’s:

· Congenital Rubella Syndrome

· Cornelia deLange Syndrome

· Down Syndrome

· Fragile X Syndrome

· Kluver-Bucy Syndrome

· Landau-Kleffner Syndrome

· Lesch-Nyhan Syndrome

· Untreated Phenylketonuria (PKU)

· Prader-Willi Syndrome

· Rett Syndrome

· Tourette Syndrome

· Tuberous Sclerosis

· Williams Syndrome

“Autism can’t define me. I define autism.” Kerry Magro


As the title of the article is suggesting, this is just the first part of the article about Autism Spectrum Disorder(ASD). In the next part, the concept of Autism will be more unclouded. Stay tuned! Let’s learn together!




Tabindah is a Clinical Psychologist. Being a mental health enthusiast, she has great zest for knowledge; reading, writing and thus sharing it with others.

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Tabindah Waheed

Tabindah Waheed

Tabindah is a Clinical Psychologist. Being a mental health enthusiast, she has great zest for knowledge; reading, writing and thus sharing it with others.

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