Symptomology: Causes, Detection and Diagnosis


At present it is not clear exactly what variables cause a repertory of behaviours consistent with a diagnosis of ASD3

There are probably many factors that contribute to the development and appearance of autism. Some are present at the moment of the child’s birth (genetic factors), while there may also be some environmental factors that contribute. Everything seems to indicate that there is a convergence of variables that come together in a child set off a chain reaction of symptoms. What does seem clear is that the risk of having autism increases if a member of the family has already been diagnosed. Finally it is important to emphasize that research has shown that the style of parenting is not a genuine cause, and nor is autism caused by vaccines.

Some ‘red-flag’ symptoms from six months onwards include 4:

  • The child does not display big smiles or other joyful expressions from around six months onwards.
  • No back-and-forth sharing of sounds, smiles or other facial expressions by nine months.
  • No babbling by 12 months.
  • No back-and-forth gestures like pointing, showing things or waving by around 12 months.
  • The child does not use words by 16 months.
  • Around 24 months, the child does not use meaningful two-word phrases (not including imitating or repetitions).
  • Any loss of language or babbling at any age.
  • The child does not turn when you call or seem to listen when you speak to him/her.
  • No symbolic play after 18-24 months (for example playing with dolls in dollhouses or toy garages).
  • Does not express “yes” or “no" either verbally or with conventional gestures.
  • Frequently becomes angry and can have strong temper tantrums despite young age.
  • Bothered by changes, for example changes to habitual routes, in the arrangement of objects, etc.
  • Seems to gain self-stimulation from certain things, for example water, lights, staring at objects, spinning on the spot, looking out of the corner of the eye, making repetitive noises...

The detection, diagnosis and assessment of autism require specialized professionals, owing to the characteristics of the disorder and the diagnostic instruments currently available. In the context of early detection it is of paramount importance that doctors, nurses and pre-school teachers are trained to identify red-flag symptoms and make a referral to specialists. A selection of appropriate assessment tools and extensive clinical experience are indispensible elements for early detection and diagnosis.

We are now able to count on very accurate tools for the early detection of autism.

The symptoms of autism can often be measured at ages as young as 18 months. Three detection tools have been published and validated for very young ages:

  • Checklist for Autism in Toddlers (CHAT)(Baron-Cohen, et al. 1992; 1996).5
  • Autism Screening Questionnaire (berument, et al, 1999).
  • Screening test for Autism in Two Year Olds (Stone et al, 2000).

CHAT is also available in Spanish and Catalan and is designed so that the paediatrician is able to detect risk symptoms for autism at the 18-month check-up.

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Category: General