Marijuana Use and Quitting Smoking: Do Risks Outweigh Benefits?

• Impairment of thinking, problem-solving skills and memory.
• Reduced balance and coordination.
• Increased risk of heart attack.
• Heightened risk of chronic cough and respiratory infections.

Potential for hallucinations and withdrawal symptoms

When someone smokes marijuana, THC rapidly passes from the lungs into the bloodstream, which carries the chemical to the brain and other organs throughout the body.  THC acts upon specific sites in the brain, called cannabinoid receptors, causing cellular reactions that ultimately lead to the “high” that users experience when they smoke marijuana.  The highest density of cannabinoid receptors are found in parts of the brain that influence pleasure, memory, thoughts, concentration, sensory and time perception, and coordinated movement.

Not surprisingly, marijuana intoxication can cause distorted perceptions, impaired coordination, difficulty in thinking and problem solving, and problems with learning and memory.  Research has shown that marijuana’s adverse impact on learning and memory can last for days or weeks after the acute effects of the drug wear off.  As a result, someone who smokes marijuana every day may be functioning at a suboptimal intellectual level all of the time.  Research on the long-term effects of marijuana use indicates some changes in the brain similar to those seen after long-term abuse of other major drugs. 

 
Long-term marijuana use can lead to addiction in the sense of compulsive drug seeking.  Long-term marijuana users trying to quit report irritability, sleeplessness, decreased appetite, anxiety, and drug craving, all of which make it difficult to quit and all of which mimic nicotine withdrawal.  These withdrawal symptoms begin within about 1 day following abstinence, peak at 2–3 days, and subside within 1 or 2 weeks following cessation.

A number of studies have shown an association between chronic marijuana use and increased rates of anxiety, depression, suicidal ideation, and schizophrenia.  It not clear whether marijuana use causes mental problems, exacerbates them, or is used in attempt to self-medicate symptoms already in existence.  Chronic marijuana use, especially in a very young person, may also be a marker of risk for mental illnesses, including addiction, stemming from genetic or environmental vulnerabilities, such as early exposure to stress or violence. 

Perhaps most alarming is the documented adverse effects marijuana has on health:

• The Heart.  One study found that the risk of heart attack more than quadruples in the first hour after smoking marijuana.  This might be from marijuana’s effects on blood pressure and heart rate (it increases both) and reduced oxygen-carrying capacity of blood.
• The Lungs.  Marijuana smokers can have many of the same respiratory problems as tobacco smokers, such as daily cough and phlegm production, more frequent acute chest illness, a heightened risk of lung infections, and a greater tendency toward obstructed airways.  Numerous studies have shown marijuana smoke to contain carcinogens and to be an irritant to the lungs.  In fact, marijuana smoke contains 50 to 70 percent more carcinogenic hydrocarbons than tobacco smoke. Marijuana users usually inhale more deeply and hold their breath longer than tobacco smokers do, which further increases the lungs’ exposure to carcinogenic smoke.
• Head and Neck.  Smoking marijuana has been linked with an increased risk of head and neck cancers.  Several case reports have found an unexpectedly high number of marijuana users among persons with cancers of the head and neck region, including the mouth, tongue, throat, and larynx.  

The bottom line: The risks of using marijuana far outweigh the benefits.