“Maternal deprivation in rats specifically leads to a vulnerability to opiate dependence. However, the impact of cannabis exposure during adolescence on this opiate vulnerability has not been investigated.
Chronic dronabinol (natural delta-9 tetrahydrocannabinol, THC) exposure during postnatal days 35-49 was made in maternal deprived (D) or non-deprived rats.
These findings point to the self-medication use of cannabis in subgroups of individuals subjected to adverse postnatal environment.”
“The surprising effect of cannabis on morphine dependence. Injections of THC, the active principle of cannabis, eliminate dependence on opiates (morphine, heroin) in rats deprived of their mothers at birth.” https://medicalxpress.com/news/2009-07-effect-cannabis-morphine.html