Anxiety and Obsessive Compulsive Disorder Issues in Autism Spectrum Disorders

Symptoms similar to those seen in Obsessive Compulsive Disorder (OCD) are often also seen in Autistic Spectrum Disorders (ASD).  It is not uncommon to see those with ASD to exhibit obsessions, compulsions, rigidity in thinking and behavior, insistence on sameness, and ritualistic behaviors.  There is evidence from genetics, neuroimaging, and the response to specific pharmacological agents to suggest that there are significant connections to be made between these two diagnostic arenas.  The degree to which these symptoms are identifiable or considered distinct has ramifications for diagnosis and treatment, as well as implications for future candidate gene studies.

In this presentation, the speaker will focus in particular on the serotonin system as a basis for many of these commonalities.  The evidence for hyperserotonemia in ASD was established in the early 1960s and has been replicated many times since that time.  In addition, tryptophan depletion studies and gene studies have both implicated serotonin as involved in ASD.  There is evidence for an increased incidence of OCD in relatives of those affected with ASD.  In both ASD and OCD, there have been findings of positive relief of symptoms with the use of selective serotonin reuptake inhibitors. 

The speaker will present pharmacogenetic data from a recent study of escitalopram in ASD.  This was a study of children and adolescents receiving the drug, with the Aberrant Behavior Checklist, Community Version, as the primary outcome measure. This genotype-blind, prospective pharmacogenetic study found the following differences in response as a function of 5-HTTLPR genotype:  1) The group of subjects with higher expressing 5-HTTLPR genotypes had a better response to pharmacotherapy than subjects with a low expressing genotype group and 2) there was a difference in the final dose by genotype groupings, with the lowest expressing genotype group having a lower final dose when compared with higher expressing genotype groups.    

Finally, there will be a discussion of emerging concepts regarding differentiation and treatment of symptoms of OCD and ASD.  Future directions for research will be reviewed and examined.