How Marijuana Affects Brain Function

Marijuana is the most commonly used illicit drug in the United States. It is estimated that 50% of American teenagers have tried marijuana for the first time before they graduate from high school. The main culprit of marijuana’s harmful health effects boils down to THC. THC, which stands for tetrahydrocannabinol, elicits psychological effects when binding with the receptors on nerve cells and fits like a lock. These receptors are commonly found in particular regions of the brain associated with memory, pleasure, and thinking. This article runs down the effects of marijuana on brain performance and how chronic use of the drug affects the individual’s everyday life.

Overview on Marijuana

Street names: pot, weed, herb.

Marijuana is made from Cannabis sativa, a hemp plant. People can take up marijuana through the smoke of the plant’s seeds, flowers, stems, and dried leaves, although marijuana can now be mixed into food. At present, marijuana can be brewed as a tea, and controversially, utilize as a medicine.  The concentrated form of marijuana is termed hash or hashish.

Regions of the Brain Affected by Marijuana

When clinging to the brain receptors, the cells in the brain release a neurotransmitter called dopamine which is responsible for the feeling of euphoria. THC influences the hippocampus, part of the brain responsible for the formation of new memories. Other parts of the brain that are highly affected by marijuana are the cerebellum and basal ganglia which primary functions include balance, coordination, and movement. The hypothalamus -- the temperature-regulating center of the brain -- can also be moderately affected by long-term use of marijuana. Chronic users of the drug who display sluggish or blunt reactions, excitability, and fear are said to have impaired function of the amygdala, the region of the brain responsible for emotional response.

Physiological and Psychological Effects of Marijuana

Effects of marijuana take place within minutes after inhalation and gradually reduced up to 4 hours the following ingestion, but the effects linger in the body systems for up to 6 months. The following summarizes the effects of marijuana:

Physiological Effects	Psychological Effects
Increased vital signs	Anxiety, Depression
Red eyes	Memory loss
Dry mouth	‘high’ or ‘stoned’
Increased appetite	Paranoia
Slowed reaction time	Magical thinking

Impacts of Marijuana

§  Learning. Students who smoke marijuana daily display reduced intellectual capacity and perform worse in school compared to non-smoking students who get higher grades. Further, regular smokers of marijuana exhibit increased absences and tardiness. They also have poor problem-solving skills and are less attentive.

§  Driving. THC in marijuana affects certain regions in the brain that have something to do with memory and concentration. That being said, drivers who are intoxicated are likely to encounter accidents due to impair judgment, slow reaction time, and poor perception of the stimulus.

§  Pregnancy. THC found in marijuana can affect the brain development and emotional maturation of the fetus. Studies disclose that babies born to mothers who use marijuana demonstrate high-pitched cry, decreased response to visual stimuli, and increased tremulousness.

§  Workplace. Smoking marijuana affects work performance. Regular and high-level use of marijuana leads to less dedication and less motivation to work. Marijuana use also leads to impaired judgment and reduced concentration, making users accident-prone.

Is Marijuana Addictive Substance?

Indeed, marijuana is addictive. Because marijuana has been a common drug in the majority of the adolescents in the United States, 1 out of 6 teens are reported to have developed addiction to the substance. Over the recent years, most especially with the tolerance of medical marijuana use and increased access to the drug, more and more people have become dependent on marijuana.

 A person is considered addictive to marijuana if there is an obvious impairment and significant suffering with at least 3 of the following symptoms:

§  Consumption of larger amounts of the drug

§  The need to increase the quantity of the drug to obtain the desired effect (drug tolerance)

§  Specific symptoms show up when the person abstains from using the drug for several days (withdrawal symptoms)

§  Increased desire to use marijuana

§  Trouble in cutting off marijuana use

§  Continue to use the drug despite experiencing negative health effects

Note: Withdrawal symptoms of marijuana are similar to that of symptoms experienced during tobacco withdrawal which normally starts 1 to 2 days after the termination of marijuana, peak between 4 and 6 weeks, and last up to 3 weeks. Withdrawal symptoms include but not limited to irritability, decreased appetite, depression, anger and insomnia.

Long-Term Effects of Marijuana Use to the Brain

A new study shows that chronic use of marijuana shrinks some parts of the brain, particularly the hippocampus and amygdala. The study was conducted for several years were the main subjects were heavy users of marijuana. The finding was surprising. The hippocampus of marijuana users decreases by 12% in size compared to people who do not smoke marijuana. Similarly, the amygdala, part of the brain that involves memory and emotion, was 7% on average. Furthermore, the study suggests that people who use marijuana for long periods have a higher tendency to report symptoms associated with mental health problems. It is also reported that they performed worse on a verbal learning test but researchers are not sure if such is associated with the decrease in volume of some parts of the brain.