The debate continues among researchers as to whether marijuana is physically addictive or a psychological habit. Chronic marijuana users may build up a tolerance to the drug's effects. They often need larger and larger amounts of marijuana to achieve the same desired effects as they had earlier, according to the National Institute on Drug Abuse (NIDA). In these heavy users, the need seems to be there either for physical or emotional satisfaction.
Physical Dependence
There are signs that marijuana may cause physical dependence through changes in brain chemistry, according to the Health Services at Columbia University. THC, the active ingredient in marijuana, travels through the bloodstream and into the brain where it attaches to nerve cells. This produces the effects that bring on the "high" feeling from marijuana. But the tolerance heavy smokers develop can mean they need eight times the dose that occasional users need. Human and animal research shows that THC changes the activities of dopamine, a neurotransmitter that is changed when a person uses other addictive drugs.
Cravings
Long-term use produces changes in the brain similar to the results seen in the long-term use of other drugs, reports the University of Maryland Center for Substance Abuse Research. This kind of addiction may lead to an uncontrollable drug craving. It may result in delinquent behavior and aggression, features that are seen in alcohol and drug addiction. Although many users do not have signs of addiction, many former marijuana users are seeking treatment though addiction centers and support groups. The Center for Substance Abuse Research explains that it is not clear if marijuana is physically addictive, but it does lead to psychological addiction and social dependence.
Psychological Dependence
Marijuana does not appear to be as addictive as alcohol or other drugs for many users, but it can become a habit, according to the Health Services at Columbia University. Counseling for people who seek treatment for marijuana addiction usually includes behavioral therapy and motivational incentives. But many users are not able to kick the habit. Teenagers who have antisocial problems may have a tendency to become addicted to marijuana use to deal with those issues, according to the NIDA.
Withdrawal Symptoms
Part of the reason marijuana may be difficult to give up for some people is the withdrawal from the drug. People trying to quit may face the same symptoms as addicts attempting to give up other drugs. The withdrawal symptoms include irritability, restlessness, fatigue, depressive moods, anger and aggression. Physical withdrawal symptoms from marijuana may include changes in appetite, nausea, weight loss, shakiness or sweating. Many marijuana users, however, can give it up with little difficulty.
