Core deficits in people with autisme spectrum disorders (ASD) are difficulties in adapting their behaviour to the social environment which hampers the possibilities to communicate adequately and to... Show moreCore deficits in people with autisme spectrum disorders (ASD) are difficulties in adapting their behaviour to the social environment which hampers the possibilities to communicate adequately and to have reciprocal relationships. These problems have a serious impact on functioning in their daily life. Since ASD are severe and lifelong conditions, it is relevant to examine how children with ASD develop troughout their life and to investigate which factors constitute an unfavourable contribution to their development. This thesis reveals that children with ASD are at specific risk of poor quality of life in adulthood when compared to children with other psychiatric disorders. Secondly, the impact of ASD on specific domains of intellectual functioning is different at different ages, implicating that re-evaluation of cognitive function during development of children with ASD is recommended during their life. Thirdly, children with ASD who are at risk of schizophrenia spectrum pathology, may show negative schizotypal symptoms, but also disorganized and positive symptoms in addition to ASD symptomatology. These symptoms of schizotypy appear to be associated with inhibition problems. We should be aware of inhibition problems in children with ASD because they may be indicators of high risk to schizophrenia spectrum pathology later in life. Show less