According to one of the most reliable governmental sources of information on drug use in America, in 2013, marijuana was the most commonly used illicit drug in the nation. The 2013 National Survey on Drug Use and Health estimated that 19.8 million Americans in the 12 or older age group (that amounts to 7.5 percent of this population) were current users of marijuana (i.e., had used this drug in the month prior to the survey). The survey also revealed a moderately rising trend in the use of marijuana year to year, as the rates of use in this age group ranged from 5.8 percent to 7.3 percent from 2002 to 2011. Some of these people who use marijuana regularly will experience long-term negative health effects.
Long-Term Effects on the Brain
As marijuana is a psychoactive drug due mainly to the activity of cannabinoids in the brain, research has delved into the impact this drug has on brain development, brain function, and its potential to cause brain damage. A significant proportion of the existing research on marijuana in the brain focuses on how it influences brain development among adolescents (i.e., comparing brains between adults who have no history or a mild history of marijuana use against those who became regular users of this drug in their teen years). As the National Institute on Drug Abuse notes, individuals who begin to use marijuana in their adolescence experience reduced abilities in terms of learning, memory, and thinking. Stated most simply, the cannabinoid activity in the developing teen to adult brain damages the neural connections that are involved in important cognitive functions.
According to one study,
individuals who began to use marijuana heavily in their teens and continued to due so as they aged into adulthood had reduced their IQ by an average of 8 points between ages 13 and 38.
The study confirmed the findings of other studies: Not all the participants studied had regained the mental abilities lost even when they stopped using marijuana in adulthood. However, individuals who began smoking marijuana in their adulthood did not show signs of a reduction in IQ points. In short, individuals who begin to use marijuana in their teens are at risk for incurring permanent damage to their brains in the form of a lower IQ and impairment in the areas of thinking, learning, and memory. This is a long-term effect because affected individuals will not be able to recapture their lost abilities over their lifetime.
Long-Term Effects on the Lungs
While the organic origin of marijuana is the hemp plant, there are fabrication processes today that can transform marijuana into concentrates that take on an oily, buttery, wax-like, or glass-like consistency. Many individuals who use marijuana concentrates smoke them; though they may believe they are experiencing a “cleaner high” in terms of their lung health, this may not be the case.
Individuals who use smoke marijuana buds or concentrates face a risk of lung problems. Smokers irritate their lungs and expose themselves to a higher risk of impaired breathing, daily cough, daily phlegm, lung infections, and other lung-involved illnesses. At present, research has not conclusively found a link between smoking marijuana and lung cancer. Some research findings, however, note that chronic heavy use of marijuana (as opposed to occasional recreational use) may be a risk factor for cancer. Research does note that marijuana smokers can experience the same type of breathing problems as tobacco cigarette smokers, and there is a link between tobacco and lung cancer.
As mentioned, marijuana use increases the risk of lung illness. But why? As the ALA explains, smoking marijuana damages the cell linings of the lungs, which diminishes their ability to fight off bacteria. According to treatment statistics, on average, marijuana users have more health care visits that are respiratory involved than nonsmokers.
The hazards the immune system faces from a person smoking marijuana goes beyond the lungs. Studies show that marijuana users are at risk for a lower immune system, which in turn impairs the body’s ability to fight off diseases, especially among those who have an existing immune system disease, such as HIV.
Lowered immunity due to smoking marijuana can also put people at risk of bringing aspergillus into their lungs. Aspergillus is a mold that can grow on marijuana. When a person smokes marijuana that has aspergillus present, this fungus can enter the lungs. This mold is known to cause long illness in those with lower-functioning immune systems. The ALA advises the public that it strongly discourages smoking marijuana, although it supports ongoing research in the area of medicinal uses of marijuana.
Long-Term Effects on the Heart
As Everyday Health reports, research published in the Journal of the American Heart Association shows that using marijuana increases the risk of major cardiovascular problems, including heart attack, stroke, and heart rhythm disorders. The study noted that young people in particular can be affected even if they presented no other risk factors for heart disorders. In other words, the use of marijuana can be highly impactful, even fatal, in those who but for the marijuana use likely would not have developed a heart disorder. Further, in 25 percent of cases, these heart disorders will cause fatality.
Everyday Health astutely notes that much of the public perception that marijuana is “harmless” comes from the mixed-legal status of this drug. Research regarding the impact of marijuana on the heart, lungs, and brain finds that this drug can be deleterious to health. Further, individuals who use marijuana may be at risk for exacerbating the ill effects of known or unknown underlying disorders, such as heart-related disorders. In terms of causing heart problems, marijuana use may cause the following effects:
- Increases a person’s heart rate up to 100 percent (usually right after smoking but the effect can persist for a few hours)
- Development of irregular heart rhythms (arrhythmias)
- Chest pain
- Cardiomyopathy (weakening of heart)
- Transient ischemic attacks (nonpermanent strokes)
- Permanent strokes
- Constriction of blood vessels (abnormal peripheral artery function)
A study in France provides helpful insight into the true extent of the risk marijuana use poses to heart function. The study focused on those who sought treatment for serious health problems that involved marijuana between 2006 and 2010. Of the 1,979 reported problems, 35 (2 percent) were cardiovascular in nature and included 20 heart attacks, three cerebral events (including an illness known as temporary cortical blindness), two cases of abnormal heart rhythm, and 10 peripheral artery problems. Of this group, the average patient was 34 years of age and previously had little to no risk factors present for cardiovascular disease. Tragically, 25 percent of the 35 patients died.
Although the number of affected persons may seem relatively small on a national scale, the study suggests that the problem may be much larger and more widespread than perceived because not everyone who is seeking health treatment discloses that they have used marijuana. But even if these numbers are worked into an equation factoring in the millions of Americans who use marijuana, the result is that an estimated 1,000 Americans each year may face a severe cardiovascular health problem directly related to marijuana use.
Long-Term Effects on Mental Health
Research indicates that long-term use of marijuana can either cause or exacerbate mental health symptoms. According to the National Institute on Drug Abuse, marijuana use can lead to depression, anxiety, and suicidal thoughts among adolescents. While marijuana is often publicly touted as a relaxant that can lessen anxiety, the opposite is often true for long-term users. Over time, a person who uses marijuana can go from experiencing one type of feeling, such as relaxation, to an opposite emotional state, such as anxiety.
Marijuana use can cause psychosis that involves different psychiatric symptoms, including hallucinations, irritability, paranoia, and derealization (feeling disconnected from reality). Typically, hallucinations only occur in heavy users. There are different types of hallucinations including: (1) tactile, which is sensing objects that are not there, (2) visual, seeing objects that are not there, and (3) audio, hearing voices or sounds that are not there. In addition, long-term users may experience states of temporary paranoia.
Again, the long-term use of marijuana can exacerbate existing mental health disorders, including schizophrenia. The mental side effects of schizophrenia include hallucinations, paranoia, and confused thoughts.
In some people, mental health effects may only manifest during a high, but in other people, the effects can emerge between marijuana uses. In some instances, marijuana use has ended, and the person has been abstinent for some time. Due to the established link between drug use and mental health disorders, when a person is screened for mental health disorders, the attending doctor or therapist will likely inquire into the person’s drug use history, if there is one. Even if marijuana use has been discontinued, it is helpful to disclose this information to a treatment professional.
Blurred Legal and Public Perceptions
Understandably, the use of marijuana creates considerable confusion among the American public. From a legal standpoint, mixed messages are sent. Under federal law, marijuana manufacture, distribution, and consumption are illegal. This status informs the drug scheduling of marijuana. Under the Controlled Substances Act, marijuana is a Schedule I drug, which reflects the federal government’s position that this drug has no medical utility. However, the states do not need to follow the government’s lead. States have been able to set forth their own laws and practices on marijuana, including making it legal by prescription for medical purposes or for prescription use. Some states stay in line with the federal government and completely prohibit marijuana manufacture, distribution, and use.
To further add to the confusion, marijuana is the subject of different studies, some of which are geared to uncovering its potential medicinal effects and others that are focused on its potentially dangerous health effects. As both of these research tracks release their findings to the public, the perceived pros and cons of this drug only deepen. One the one hand, marijuana has therapeutic value, but on the other hand, marijuana can have serious health consequences.
Researchers, governmental authorities, and medical associations appear to advocate research in the area of the therapeutic effects of marijuana while at the same cautioning against its use. The best practice, therefore, may be for the public to informatively weigh the pros and cons of marijuana. This balancing act is not unheard of regarding drugs of abuse. Many drugs, including heroin and cocaine, were initially released to the public or medical providers for therapeutic use but later lost their lawful status for public use because the addiction potential outweighed the potential medicinal value. Although there is no general consensus on whether marijuana should be legal or illegal, ongoing research is helping Americans to make an informed decision as to whether the purported benefits of marijuana outweigh its many negatives.