With respect to marijuana withdrawal, a growing number of controlled studies suggest the presence of a reliable and empirically valid withdrawal syndrome for cannabis users [26–31]. Withdrawal symptoms observed include anger, aggression, irritability, restlessness, shakiness, sleep disturbance, decreased appetite and decreased weight [26]. The time–course of withdrawal symptoms is similar to the time–course of symptoms associated with other drugs such as tobacco. Onset begins within 1–3 days of abstinence, with the peak effects occurring on or before day 6, persisting for as long as 10–14 days [26,30]. Reports suggests that as many as 67% of cannabis-dependent adolescents reported problems with withdrawal [32], while 16% of individuals who smoked at least 21 days per year reported withdrawal [33].
