So far, the only medication successful in suppression of withdrawal symptoms in the laboratory was a single dose of 10mg/day oral synthetic THC (dronabinol) [44]. Oral THC was also more effective than placebo in an outpatient study in which oral THC was given to 8 adult, daily cannabis users who were not seeking treatment in a 40-day, within-subject design study [44]. Participants received daily doses of placebo, 30 mg (10 mg/tid), or 90 mg (30 mg/tid) oral THC during three 5-day periods of abstinence from cannabis use, separated by 7–9-day periods of cannabis smoking as usual. Comparison of measures of withdrawal symptoms across conditions indicated a dose-dependent reduction of withdrawal discomfort by THC. Minimal adverse effects were associated with either THC dose. This demonstration of dose-response effect replicates and extends prior findings of the pharmacological specificity of the cannabis withdrawal syndrome [43].
