Summary
background So far, little is known about the comorbidity of substance use disorders (sud) and autism spectrum disorders (asd).
aim To increase our knowledge of sud in asd patients by means of a broad explorative study.
method In a cross-sectional study 70 patients with asd were compared with 53 patients with adhd. Both groups included some patients with sud and without sud. Comparisons were drawn at three different levels: phenotype, endophenotype and genotype.
results At the phenotypical level, risk factors for sud were similar for asd and adhd (early onset smoking, adverse family history, parental addiction). The subgroup asd-with-sud reported better social orientation than the subgroup asd -without - sud, in spite of having impaired functioning at the phenotypical level and more cognitive problems at the endophenotypical level. At the genetic level, asd could be differentiated from adhd on the basis of three candidate genes, but this differentiation was irrespective of sud status.
conclusion sud occur less frequently with asd than with adhd, but when they occur, they are just as severe. These results have implications for treatment.