This trial will examine the efficacy of lithium in providing symptomatic relief from the
withdrawal discomfort experienced by some dependent users of cannabis on cessation of regular
use. Significant withdrawal may be a barrier to achieving abstinence in some clients and can
be associated with marked disturbances in mood, sleep, hostility and aggression. Relief from
such symptoms may be important in helping some clients achieve a period of abstinence and
facilitate subsequent entry into a relapse prevention program.