The quasi-morphine withdrawal syndrome: effect of cannabinol, cannabidiol and tetrahydrocannabinol

Delta-9-tetrahydrocannabinol (THC), the main psychoactive principle of cannabis, has been shown to attenuate the exhibition of signs of the quasi-morphine withdrawal syndrome in rats. Cannabinol (CBN) showed the same activity but required a dosage of approximately eight times that of THC to produce an equivalent effect. Cannabidiol was without effect at the dosage levels used. The efficacy of these cannabinoids and the potency differences recorded in this study are in accord with their effects on other behaviours, both in experimental animals and in man. The activity of THC and CBN was not affected by the narcotic antagonist, naloxone.