Marijuana is not physically addicting like heroin or alcohol, though those detoxing from everyday use will feel symptoms ranging from irritably to insomnia, mostly from the psychological dependencies created by using the drug. The craving can be very intense and set up the addict for a relapse because of the compulsion to relieve the symptoms by smoking more marijuana. Appetite While smoking marijuana increases the appetite, quitting has the opposite effect. Sleep Sleep patterns become disrupted when going through marijuana withdrawal, because the body becomes accustomed to the lethargic qualities of the drug in order to sleep. Nerves Anxiety is a common symptom of marijuana withdrawal characterized by inflated paranoia, nervous hand and leg movements and intense worrying. Length Like detox from cigarettes, the intense cravings tend to subside within a day or two. Mental cravings will continue until the addict receives treatment through therapy or a self-help program such as Narcotics Anonymous. Chemicals THC, which is the active ingredient in marijuana, stays in the body for months and is stored in the fat cells. As the body expels the chemical over time, cravings may temporarily return.