Thesis defense Evelien Barendse (Donders series 284)

7 September 2017

Promotors:  prof. dr. R. Kessels, prof. dr. A. Aldenkamp (MU)

Copromotors: dr. M. Hendriks, dr. J. Jansen (MU)

Autism Spectrum Disorders in High functioning Adolescents; Diagnostic considerations (AHA)

The studies presented in this thesis aimed to investigate the use of diagnostic instruments and the neurocognitive profile of high-average intelligent adolescents with ASD, and gain more insight in the mechanisms underlying this disorder in these teens.
In the first part of this thesis, clinical studies are presented that investigated the use of diagnostic instruments and the neurocognitive profile of high-average intelligent adolescents with ASD. We found that high-functioning adolescents with ASD do experience many social cognition and executive functioning difficulties in daily life situations, and that these difficulties cannot always be objectified in a (neuro)psychological assessment. In more structured settings, these intelligent teens are able to apply compensation strategies,  although these strategies are  often not functional on the level of multisensory information processing that is needed in real life social interaction. The second part of this thesis described research into the mechanisms underlying ASD in high-functioning adolescents. We examined the working memory brain network integrity in high-functioning adolescents with ASD, investigated the neurodynamics of the brain resting state networks, and MR spectroscopy was performed and directed to two major neurotransmitters: glutamate and gamma aminobutyric acid (GABA). These studies showed evidence for a loss of global efficiency, changes in resting-state fMRI temporal neurodynamics, and imbalanced neurotransmitter levels of excitation and inhibition associated with ASD in high functioning adolescents, which may be related to the constant compensatory tendency in these youngsters. In general, this thesis shows that structured (neuro)psychological assessment in high-functioning adolescents with ASD. because of these compensation strategies, should always be complemented with real life observations and by-proxy reports of significant others, to get a full ‘Aha-erlebnis’ and as a psychologist be able to give good advice.