Abrupt cessation of chronic and frequent cannabis use is associated with cannabis withdrawal. Cannabis withdrawal syndrome is a clinically significant diagnosis and a criterion of cannabis use disorder (CUD) marked by mood and sleep disturbance symptoms, appetite and/or weight loss and restlessness, and physical symptoms such as abdominal pain, shakiness/tremors, sweating, fever, chills and headaches. The goal of this chapter is to fully characterize the clinical significance, time course, neurological mechanisms and treatment of cannabis withdrawal. The chapter synthesizes studies examining individual difference factors (demographics, cannabis use patterns, genetics and heritability and psychiatric comorbidity) that place some people at disproportionally higher risk for cannabis withdrawal or greater severity of symptoms. The cyclical nature of resuming use due to the inability to cope with the distress of cannabis withdrawal is negatively reinforcing and presents major challenges to individuals trying to abstain from problematic cannabis use. Implications for evidence-based strategies that can help mitigate the psychological and physiological symptoms of cannabis withdrawal are discussed.

Endogenous cannabinoids assist in regulation of hunger, pain perception, inflammation, and stress responses. Tetrahydrocannabinol (THC), a component of cannabis, activates cannabinoid receptors, producing effects that are often emotionally pleasing and cognitively interesting. THC effects impair complex tasks, such as driving. Addiction develops in 8--10 percent of all cannabis users, and in about 25 percent of daily users. Regular adolescent users are especially vulnerable. Adverse outcomes of cannabis addiction include too much time spent intoxicated, important activities given up, worsening of psychological problems, and failed attempts to stop use. The withdrawal syndrome includes irritability, anxiety, depression, and sleep difficulties. Long-term heavy use of cannabis is associated with academic failure and subtle cognitive impairment. Medical uses of cannabis include relief of nausea, appetite improvement, and lessened neuropathic pain. Medical use may increase cannabis addiction, a risk somewhat similar to that of other, more traditional medications for pain, anxiety, and attention disorders. Because cannabis is now a commercial product, its potency has increased in recent years.