What Marijuana Does To Your Brain And Body

When THC hits brain cells, it causes them to release dopamine, a feel-good brain chemical. This is a part of the brain's reward system, which makes you feel good when you do things that ensure the survival of yourself and your offspring. These things include eating and having sex.

When over-excited by drugs, the reward system creates feelings of euphoria.

When the rewards system is overstimulated, for example, by the abuse of drugs like cocaine, it can go haywire and cause a dependence (or in extreme cases addiction) on whatever is providing the rewarding feeling. It can also diminish how rewarding normal things, like eating, feel.

This can cause apathy and dependence on the drug.

The active ingredient in marijuana acts in the part of the brain called the hippocampus to alter the way information is processed and how memories are formed. Animal studies have shown that this is particularly true while the brain is still developing — specifically why the legal smoking age is 21 in the states that have legalized it.

This blockage of memory formation can cause cognitive impairment in adulthood if use happens during adolescence, at least in rats. It can also quicken age-related brain cell loss, though marijuana has been shown to slow the progression of Alzheimer's disease.

THC messes with brain areas called the cerebellum and basal ganglia, which regulate balance, posture, coordination, and reaction time. When these brain areas are disturbed, the user has a harder time walking and talking correctly, becoming quite clumsy. It also impacts their ability to drive.

Although there is no conclusive evidence that marijuana makes users depressed (it's just as likely that people who are depressed use pot), one recent study from the Netherlands found that smoking cannabis increases the risk of depression for young people who have a genetic vulnerability to the mental illness. 

In the long-term, smoking marijuana increased depressive symptoms in subjects with a special serotonin gene responsible for increased risk of depression.  

Somewhere between 20 and 30 percent of recreational marijuana users react with intense anxiety after taking the drug, making it one of the most commonly reported side effects. 

Marijuana users who have taken large doses of the drug may experience acute psychosis, which includes hallucinations, delusions, and a loss of the sense of personal identity. These episodes may be related to the link between marijuana use and psychosis, but are distinct.

Along with actual psychosis, cannabis users can also have audio and visual hallucinations from the effects on the brain areas that process what we see and hear.

These audio hallucinations include “looping” sounds, where one particular sound (that is usually one syllable in duration) will repeat over and over again until it is either replaced by a different sound or the effects of THC begin to wear off.

There are five stages of sleep, which get progressively deeper as the night goes on. The first four stages are called rapid eye movement, or REM. THC, the main active chemical in marijuana, has been shown to interrupt the later phases of REM sleep, the point during the night that is most crucial to making the body feel re-energized when you wake up.  

Within a few minutes of inhaling marijuana, your heart rate increases, sometimes by 20 to 50 beats per minute (normal is 70 to 80 beats per minute). In some cases, like when taking other drugs with marijuana, heart rate can double.

This heart rate increase usually subsides relatively quickly, in about 20 minutes.

The traditional red eyes of a marijuana user — Visine anyone? — come from blood vessels expanding in the eye. 

One uncomfortable effect of smoking weed is dry mouth or thirst.  

The common side-effect, equivalent to the feeling of having a bunch of cotton balls shoved in your mouth, is not just the result of inhaling hot smoke. It turns out cannabinoids receptors are located where our saliva is produced. When these receptors are activated by cannabis use, they inhibit the production of saliva. 

After marijuana intake, most people feel the need to eat. And eat a lot. The drug increases food enjoyment and interest in food, increasing appetite. This is thought to be caused by the THC interacting with the cannibinoid receptors in a brain area called the hypothalamus.

Interestingly, a link has been drawn between milk products and cannibinoids. Some researchers think that these cannibinoids in milk play an important role in infant survival, because they stimulate the child's appetite and cause them to eat more and suckle, which could be why THC has a similar effect in adults.

All The Reasons Pot Is Good For You >