Opiates lower the excitation of locus coeruleus via decreasing the firing activity of neurons. It is implicated that dysfunction of opiatergic systems might be mostly responsible for causing social withdrawal behaviour. Increased brain opiatergic activity during neonatal period might decrease social motivation and cause social withdrawal in autistic children. Painful stimulants in post travmatic stress disorder patients increase opiate synthesis in brain and repetetive painful stimulants and şashbacks might reinforce this neurobiological process. Naltrexone, an opiate antagonist, is shown to decrease the şashbacks in patients with posttraumatic stress disorder. The underlying mechanism in which opiate antagonists diminish the self injurious behaviour in autistic children might involve the reduction of opiatergic activity which is increased by painful stimuli and self injurious behaviours. Regarding two cases who are admitted to our inpatient unit, the effects of opiate antagonists as well as their neurobiological mechanisms which lower agression and other potential pharmocological indications were discussed.
Naltrexone, autism, self injurious behaviour, opiatergic system