Itai Danovitch, David A. Gorelick
Initial Characterization of Cannabis Addiction
Before the 1980s, cannabis was not thought to produce significant dependence.6 Physical dependence, particularly the presence of a withdrawal syndrome, was not well characterized, animal models had not convincingly demonstrated reinforcing effects, and the neurobiology of cannabis was not well understood. Further, cannabis use did not seem to cause the dramatic harms typified by other drugs of abuse, such as alcohol, cocaine, and heroin.
Discussion of adverse effects often focused on the “amotivational” syndrome,7 a syndrome that was never fully disentangled from cannabis intoxication itself. The primary psychoactive component of cannabis, tetrahydrocannabinol (THC), was identified in 1965,8 but it was not until the 1990s, when the first cannabinoid receptor (CB1) was described, that researchers began to characterize the endocannabinoid system. CB1 receptors were found to be localized throughout the brain, and although their purpose was not well-understood, cannabis exposure was shown to alter them. 1-s2.0-S0193953X12000202-main.pdf