Marijuana Abuse Effects
Marijuana abuse effects are created by THC (delta-9 tetrahydrocannabinol). The THC in marijuana acts on "cannabinoid" receptors which are found on neurons in many places in the brain. These brain areas are involved in memory (the hippocampus), concentration (cerebral cortex), perception (sensory portions of the cerebral cortex) and movement (the cerebellum, substantia nigra, globus pallidus). When THC activates cannabinoid receptors, the normal functioning of these brain areas change due to marijuana abuse effects on the user. The effects of marijuana start as soon as 1-10 minutes after it is taken and can last for 3-4 hours or longer.
Scientists have known for a long time that THC interacted with cannabinoid receptors in the brain, but did not know why the brain would have such receptors. They thought that the brain must make some kind of substance that naturally acted on these receptors. In 1992, they found the answer...anandamide. Anandamide is the brain's own THC (just like "endorphin" is the brain's own morphine). Still, scientists are not sure what the function of anandamide is in the normal brain.
Marijuana Abuse Effects on the Brain
Scientists have learned a great deal about how THC acts in the brain to produce its many effects. When someone smokes marijuana, THC rapidly passes from the lungs into the bloodstream, which carries the chemical to organs throughout the body including the brain.
In the brain, THC connects to specific sites called cannabinoid receptors on nerve cells and influences the activity of those cells. Some brain areas have many cannabinoid receptors while others have few or none. Many cannabinoid receptors are found in the parts of the brain that influence pleasure, memory, thought, concentration, sensory and time perception, and coordinated movement.
Short-term marijuana abuse effects include problems with memory and learning, distorted perception, difficulty in thinking and problem solving, loss of coordination, and increased heart rate. Research findings for long-term marijuana use indicate some changes in the brain similar to those seen after long-term use of other major drugs of abuse. For example, cannabinoid (THC or synthetic forms of THC) withdrawal in chronically exposed animals leads to an increase in the activation of the stress-response system and changes in the activity of nerve cells containing dopamine. Dopamine neurons are involved in the regulation of motivation and reward, and are directly or indirectly affected by all drugs of abuse.
Marijuana Abuse Effects on the Heart
One study has indicated that an users risk of heart attack more than quadruples in the first hour after smoking marijuana. The researchers suggest that such an effect might occur from marijuana abuse effects on blood pressure and heart rate and reduced oxygen-carrying capacity of blood.
Marijuana Abuse Effects on the Lungs
A study of 450 individuals found that people who smoke marijuana frequently but do not smoke tobacco have more health problems and miss more days of work than nonsmokers. Many of the extra sick days among the marijuana smokers in the study were for respiratory illnesses.
Even infrequent use can cause burning and stinging of the mouth and throat, often accompanied by a heavy cough. Someone who smokes marijuana regularly may have many of the same respiratory problems that tobacco smokers do such as daily cough and phlegm production, more frequent acute chest illness, a heightened risk of lung infections, and a greater tendency to obstructed airways.
Marijuana abuse effects may also lead to cancer of the respiratory tract and lungs due to marijuana smoke. A study comparing 173 cancer patients and 176 healthy individuals produced strong evidence that smoking marijuana increases the likelihood of developing cancer of the head or neck, and the more marijuana smoked the greater the increase. A statistical analysis of the data suggested that marijuana smoking doubled or tripled the risk of these cancers.
Marijuana use has the potential to promote cancer of the lungs and other parts of the respiratory tract because it contains irritants and carcinogens. In fact, marijuana smoke contains 50 to 70 percent more carcinogenic hydrocarbons than does tobacco smoke. It also produces high levels of an enzyme that converts certain hydrocarbons into their carcinogenic formâ€”levels that may accelerate the changes that ultimately produce malignant cells. Marijuana users usually inhale more deeply and hold their breath longer than tobacco smokers do, which increases the lungs exposure to carcinogenic smoke. These facts suggest that, puff for puff, marijuana abuse effects may increase the risk of cancer more than smoking tobacco.