Neurobiology of affiliation

Neurobiology of affiliation implications for autism spectrum disorders... 

Although social attachment and impairment of social behaviors are evident in a wide range of psychopathology, including childhood trauma, personality disorders, and anxiety disorders, an extensive review of this subject is beyond the scope of this chapter. The focus of this section will thus be primarily limited to the neurobiology of affiliation as it relates to autism spectrum disorders. 

In human beings and most mammals, affiliation is an essential part of the life process, as it is necessary for both reproduction and survival. There are nonetheless instances in nature of profound lack of affiliative behavior. For example, children with autism spectrum disorders have significant difficulties in social skills, including lack of positive reinforcement from social interaction, poor eye gaze, impairment in social interactions, difficulties in attachment, and difficulties in nonverbal and, often, verbal communication. Deficits of this kind have led us to the study of the neurobiology underlying attachment and affiliation. 

Additionally, an opioid antagonist, naltrexone, has been used to treat children with autism. The results from these studies have been mixed, with some studies showing a mild decrease in hyperactivity and self-injurious behavior, and improved attention (Gillberg, 1995). The children who respond best to this medication appear to have more severe abnormalities in their beta endorphin levels (Bouvard et al., 1995). Overall, the research suggests that the endogenous opioid system, which is important in the reward aspects of affiliation, may also play a role in the neurobiology of autism. 

Carter CS, Keverne EB (2002) The neurobiology of social affiliation and pair bonding. In Hormones, Brain and Behavior, vol. 1 (Pfaff D, et al.), pp. 298-338. San Diego Academic Press. 

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