Mice with autism-like behaviours were used to measure the effects of cannabinoids on measurable behaviour: forced swimming and spontaneous wheel running. The mice were administered the drugs MDMA and methamphetamine, and the neurotoxin MPTP; they demonstrated increased activity with the drugs and decreased with MPTP. Cannabinoids (delta-9 tetrahydrocannabinol, or THC) appeared to reduce activity, suggesting it has a role in regulating the repetitive behaviours of the mice, and therefore possibly humans.
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The autistic-like mice (BTBR T+tf/J) with the qualifying condition of repetitive and excessive grooming, similar to those found in severe autism in humans, were given THC and their behavior changed significantly. The reduction in this behavior, which can be extremely difficult for both the autistic individual and those who care for them, implies that cannabis oil or a strain of cannabis with a beneficial amount of THC could be a way of helping children with autism.
Many parents worry about the symptoms of autism. There is plenty of anecdotal evidence of THC being useful for the behavioral issues that accompany an autism spectrum disorder but little scientific evidence; this paper does not add significantly to the THC/autism debate. The endocannabinoid system is understood to be different in the brains of some autistic children, pointing to the use of medical cannabis as a potential for future clinical trials. Cannabis is becoming legal in the United States, raising hopes of the use of a drug with few side effects to help with children and adults with social interaction, repetitive behavior, weight gain and other issues related to ASD. More research is needed.
The administration of THC appeared to reduce the prevalence of repetitive behaviours such as spontaneous wheel running whereas the amphetamines (MDMA and methamphetamine) had no such effect and the neurotoxin MPTP significantly reduced them due to the damage caused. The reasons for this are not well understood, and it is unclear as to how similar the brains of these experimental rats are to autistic humans’ brains. The applicability of this study is doubtful, given the complexity of the issues at hand.