“Methamphetamine (METH) is a potent psychostimulant with neurotoxic properties…

Preclinical studies have shown that natural (Δ9-tetrahydrocannabinol, Δ9-THC) and synthetic cannabinoid CB1 and CB2 receptor agonists exert neuroprotective effects on different models of cerebral damage. Here, we investigated the neuroprotective effect of Δ9-THC on METH-induced neurotoxicity…

Our results indicate that Δ9-THC reduces METH-induced brain damage via inhibition of nNOS expression and astrocyte activation through CB1-dependent and independent mechanisms, respectively.”

http://www.ncbi.nlm.nih.gov/pubmed/24844285

Full-text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4028295/