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154 ACQ Volume 11, Number 3 2009 ACQuiring knowledge in speech, language and hearing
clinically unfathomed decisions should be avoided. Precision
in the classification and subtypes carries implications for
outcome and response to treatment.
References
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autism in US special education. Pediatrics, 117, 1028–1037.
Sikora, D. M., Hartley, S. L., McCoy, R., Gerrard-Morris, A.
E., & Dill, K. (2008). The performance of children with mental
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relation to social activities), on returning to school, and on
alleviating the familial stress in relation to his anxiety. Sam
was referred for an ADOS assessment for clarification of
whether his social difficulties and anxiety were exacerbated
by an underlying co-morbid PDD condition.
Sam’s ADOS-G score suggested a diagnosis of autism.
Despite this, a diagnosis of autism did not appear to be
appropriate to explain his presenting concerns. First, for a
diagnosis of autism to be warranted, the young person must
show developmental difficulties by the age of 3 years old. As
his development was reported to be normal until the age of
approximately 10 years, he did not meet this criterion.
Second, impairments in the quality of social relationships
must always have been present. Again, he was reported not
to have shown difficulties in his social development until 10
years of age. Additionally, during the assessment of the
ADOS-G, his social interactions improved in quality over time
suggesting that his social skills deficits may be attributed to
his marked anxiety. Third, autism is also characterised by
restricted, stereotyped and/or repetitive interests. He showed
no evidence of exhibiting such behaviours or interests,
showed no evidence of rigidity of behaviour, and did not
perseverate on any object or topic during the assessment.
Finally, his significant language impairment was likely to have
impacted on the ADOS-G score by artificially inflating the
result. Therefore, it was concluded that his difficulties could
be better explained by his high levels of anxiety, his
diagnosed language impairment and non-verbal learning
disorder, and his poor social skills that were likely to have
been exacerbated due to his long period of school refusal.
Sam’s profile gives clear evidence of the complexity
of the difficulties inherent in assessing young people who
present to a mental health service with mental health and
developmental disorders. The ADOS-G was an essential
diagnostic tool for clear diagnostic clarification and had a
direct impact on treatment provided. For Sam, ADOS-G
gave a false positive diagnosis and he therefore did not get a
PDD diagnosis. However, the mental health diagnosis for his
anxiety and school refusal were addressed by the family and
education staff, and appropriate supports and interventions
were implemented at home and at his high school. Both
his language and learning difficulties were targeted in the
intervention program.
This case example supports the view that ADOS-G can be
regarded as a useful clinical tool to assist with the differential
diagnosis. As Sikora et al. (2008) pointed out, several clinical
issues should alert clinicians to avoid making hasty and clinically
unsupported diagnoses. These include 1) the risk of a false
positive diagnosis of PDD, 2) a relative risk of incorrectly
classifying mood disorders, and 3) a relatively lower risk of
misclassifying disruptive behaviour disorders. The need for
multiple sources of information during the diagnostic
process, accurate differentiation of mental health disorders
from PDD, as well as the identification of co-morbid mental
health disorders and PDD warrant careful consideration.
The referral pathway recommended provides a guideline
for clinicians to follow so that the complex and subtle clinical
issues can be identified and addressed.
Conclusion
The referral pathway currently used in CYMHS has been
established to ensure that information from multiple sources
and the ADOS-G may be used to help inform clinical
judgment for making a differential diagnosis for this client
group. Importantly, ADOS-G should not be used as the sole
piece of evidence for an ASD diagnosis and hasty and
Nickolina Aloizos completed her undergraduate degree in speech
pathology at University of Queensland followed by her Master of
Health Science (Speech-Language Pathology), University of Sydney.
She also has a teacher’s diploma in Speech and Drama from Trinity
College of Music. Nickolina currently works at the North West
CYMHS in Brisbane. She has an interest in the differential diagnosis
and treatment for communication, developmental and mental health
disorders in young people.
Correspondence to:
Nickolina Aloizos
Speech Pathologist
North West CYMHS
phone: 07 3335 8737
email: