Four related neuropeptides in autism

Date of Completion

January 1997


Biology, Neuroscience|Biology, Animal Physiology|Psychology, Clinical




The neuropeptides oxytocin, vasopressin and beta-endorphin have been implicated in the regulation of social behavior in animals. It has been suggested that the social deficits of autism are related to abnormalities in these peptides. Plasma samples of normal and autistic children were analyzed for levels of OT, prohormone OT-X, vasopressin and beta-endorphin, and measurements were related to behavioral variables. Mean OT level was decreased in the autistic group relative to controls. OT-X levels tended to be very low to nondetectable in the normal group, but were relatively higher and more variable in the autistic group. Oxytocin demonstrated stronger relationships with physiological factors and behavior in both autistic and normal children than the other peptides.^ Higher OT corresponded with advancements in adaptive skills in normal children, while VP and BE showed the opposite relation to behavior. In autistic children, elevations in OT, VP and BE corresponded with deficits in adaptive and/or intellectual functioning. However, VP's association with IQ-related behavior deficits was attributable to emotional reactivity. Results are discussed in terms of hypothesized peptide interactions. ^