The first aim of this thesis is to gain more insight in the phenotypical variance of core and eo-occurring symptoms of ASD. The specific research questions concerning this first aim are:
1. Do symptom profiles on core ASD symptoms support a categorical view with different underlying diagnostic categories or do they reflect a dimensional distribution of ASD symptoms?
2. How are eo-occurring symptoms associated with severity of core ASD symptoms?
3. What is the influence of quality of social relations, ASD symptom severity and IQ on the manifestation of eo-occurring anxiety in ASD?

The second aim of this thesis is to determine whether presumed endophenotypical correlates of ASD predict future symptom severity of this condition.
The particular research questions concerning this second aim are:
1. Does FTD in school aged children with ASD predict a higher symptom severity of ASD in adolescence over and above the ASD symptom severity in childhood? Or does FTD better predict prodromal symptoms of psychosis in adolescence?
2. Does poor performance on indices of social cognition, namely Facial Recognition and Identification of Facial Emotions in childhood predict higher symptom severity of ASD in adolescence over and above the ASD symptom severity in childhood?
3. Does a detail-focused cognitive style in childhood, operationalized as superior disembedding performance on a visuo-spatial test, predict higher symptom severity of RRBI symptoms in adolescence over and above the RRBI symptoms in childhood?

F.C. Verhulst (Frank) , K. Greaves-Lord (Kirstin)
Erasmus University Rotterdam
hdl.handle.net/1765/94711
Pediatric Psychiatry

Eussen, M. (2015, September 4). Heterogeneity in autism spectrum disorder: clarifying core- and co-occurring characteristics, correlates and course. Retrieved from http://hdl.handle.net/1765/94711