Marijuana is the most commonly used illicit drug in the United States, typically smoked as a hand-rolled cigarette (joint) or in a pipe or water pipe (bong). The drug is also smoked in what’s called a blunt—a cigar that’s been emptied of tobacco and refilled with a mixture of marijuana and tobacco. Marijuana smoke has a pungent and distinctive sweet-and-sour odor.

Another way of ingesting the drug is to mix the plant’s leaves, flowers, stems or seeds into food or to brew the leaves as a tea.

History of Marijuana

Some varieties of cannabis plants are also known as hemp, although “hemp” more commonly refers to a fiber derived from such plants. Historically, hemp fiber has been used to make rope, paper, fabrics and sail canvas. Today, hemp fiber is used to create concrete-like blocks for construction projects, bioplastics, jewelry and biofuels. In colonial America, hemp production was required by English rule. George Washington grew it as a crop at Mount Vernon. At that time, hemp plants were low in tetrahydrocannabinol (THC), the active component of cannabis, and crops were valued for their role in industry.

Use of medicinal cannabis began in America in the 1850s, when products with cannabis extracts were produced and sold to treat maladies such as pain and muscle spasm. Soon after, pharmaceutical regulations were introduced in some states. Products containing habit-forming substances such as cannabis were often labeled as poisons and, in some cases, were available only with a physician’s prescription.

Today, marijuana is classified by the federal government as a Schedule I substance, which means the drug presents a high risk for abuse and is deemed to have no medicinal uses. However, several states have legalized marijuana for adult recreational use, and 23 states as well as the District of Columbia allow use of medical marijuana to treat certain medical conditions.

While many have called for the legalization of marijuana to treat pain and nausea caused by HIV/AIDS, cancer, and other conditions, clinical evidence does not show that the therapeutic benefits of medical cannabis or medical marijuana outweigh the health risks. To be considered a legitimate medicine by the U.S. Food and Drug Administration (FDA), a drug must have well-defined and measurable ingredients consistent from one unit (such as a pill or injection) to the next. Since the cannabis plant contains hundreds of chemical compounds that vary from plant to plant (and those various compounds may cause different effects) and because the drug is typically ingested via smoking, its medicinal use is difficult to evaluate.

At this time, several THC-based drugs have been approved by the FDA to treat pain and nausea. And scientists continue to investigate the medicinal properties of other chemicals found in the cannabis plant, such as cannabidiol, a non-psychoactive compound being studied for its effectiveness in treating pain, pediatric epilepsy and other conditions.

It’s also important to note that marijuana potency has increased significantly over the years. In 2012, the THC concentration in marijuana samples confiscated by law enforcement averaged near 15 percent, compared with an average concentration of  four percent in the 1980s. High-potency forms of the drug can expose new users to increased concentrations of THC and greater risk of experiencing adverse or unpredictable reactions. For frequent users, higher potency can increase the risk of marijuana addiction.

Learn more about the history of marijuana and legislative policy.

The Effects of Marijuana Abuse

When marijuana is smoked, THC passes rapidly from the lungs into the bloodstream, which carries the substance to the brain and other organs throughout the body. THC is absorbed more slowly when ingested through food or drink.

Regardless of how THC is ingested, the substance acts specifically on the brain cell’s cannabinoid receptors. These receptors—ordinarily activated by THC-like chemicals produced naturally by the body—are part of the neural communication network, called the endocannabinoid system, which plays an important role in normal brain development and function.

The highest density of cannabinoid receptors is found in parts of the brain that influence pleasure, memory, thinking, concentration, sensory and time perception, and coordinated movement. Marijuana over-activates the endocannabinoid system, causing the “high” and other effects that users experience, such as:

• Altered perceptions and mood
• Impaired coordination
• Difficulty with thinking and problem solving
• Disrupted learning and difficulty recollecting memories
• Decreased appetite

Research indicates that using marijuana can cause or exacerbate problems in daily life. Heavy users tend to report lower life satisfaction, poorer mental and physical health, more relationship problems and less academic or career success when compared with non-using peers. Use of the drug is also associated with a higher likelihood of dropping out of school. Several workplace studies associate marijuana use with increased absences, tardiness, accidents, workers’ compensation claims and job turnover.

Health Risks

Marijuana use is associated with a range of health issues, particularly related to heart and lung problems and mental health conditions.

Marijuana smoke is an irritant to the lungs, and frequent smokers can experience many of the same respiratory problems experienced by tobacco smokers, such as:

• Daily cough and phlegm production
• Frequent acute chest illness
• Heightened risk of lung infections
• Damage to the immune system
• Kills brain cells and damages central nervous system
• Fertility issues
• Increased heart rate and blood pressure

One study found that people who smoke marijuana frequently but do not smoke tobacco have more health problems and miss more days of work than those who don’t smoke marijuana, mainly due to respiratory illnesses. It is not yet known whether marijuana smoking contributes to the risk for lung cancer.

Research also indicates that use raises the heart rate by 20-100 percent shortly after smoking; this effect can last up to three hours. One study found that marijuana smokers have a 4.8-fold increase in the risk of heart attack in the first hour after using the substance. The risk may be even greater for older adults and those with cardiac vulnerabilities.

A number of studies link chronic marijuana use and mental illness. High doses can produce a temporary psychotic reaction in some users. Use of the drug can also worsen the course of illness for patients who have schizophrenia. A series of large, longitudinal studies also shows a link between marijuana and the development of psychosis.

Marijuana abuse has also been associated with other mental health problems, such as:

• Depression
• Anxiety
• Personality disturbances
• Suicidal thoughts (among adolescents)
• Lack of motivation to engage in typically rewarding activities

More research is needed to better understand these mental health links and ramifications.

Using marijuana during pregnancy is associated with increased risk of neurobehavioral problems in babies. Because THC and other compounds mimic the body’s own endocannabinoid chemicals, marijuana use by pregnant mothers may alter the developing endocannabinoid system in the brain of the fetus. Consequences for the child can include difficulties related to attention, memory and problem solving.

Marijuana has also been shown to negatively affect the brain development of young people who are heavy users. The effects on thinking and memory may last a long time or even be permanent. A study of individuals who began using the drug in adolescence revealed substantially reduced connectivity in areas of the brain responsible for learning and memory. A long-term study in New Zealand showed that people who began smoking the drug heavily in their teens lost an average of eight points in IQ between ages 13-38. The lost cognitive abilities were not fully restored in those who quit smoking marijuana as adults. Those who started smoking the drug in adulthood did not show significant IQ declines.

Additionally, because it impairs judgment and motor coordination, marijuana use contributes to a greater risk of injury or death while driving a car. Data analysis suggests that marijuana use more than doubles a driver’s risk of being in an accident. On a related note, the combination of marijuana and alcohol increases driving impairment more than either substance alone.

Is Marijuana Addictive?

Contrary to common belief, marijuana is an addictive substance. Research suggests that approximately nine percent of users develop addiction. The estimated incidence of addiction increases among those who start using at a young age (an estimated 17 percent develop addiction) and among people who use the drug daily (an estimated 25-50 percent become addicted).

Individuals who are addicted to cannabis may experience symptoms of withdrawal when attempting to stop using the drug. Long-term users who try to quit report withdrawal symptoms such as irritability, sleeplessness, decreased appetite, anxiety and drug craving–all of which can make it difficult to abstain. Behavioral interventions, including cognitive-behavioral therapy and motivational incentives (e.g., providing vouchers for goods or services to patients who remain abstinent) have proven effective in treatment and rehab for marijuana addiction. Although medications to address marijuana/cannabis addiction are not currently available, recent discoveries about the endocannabinoid system offer promise in developing medications to ease withdrawal symptoms, block the drug’s intoxicating effects, and prevent relapse.

Marijuana Addiction Symptoms

Addiction to marijuana is most commonly diagnosed during adolescence or young adulthood. However, recent trends toward greater societal acceptance of marijuana use and increased availability of both recreational and medical forms of the drug may increase the addiction rate in older adults. As with other types of drug addiction, there are behavioral and physical signs that can signal marijuana addiction (known medically as cannabis use disorder).

Behavioral changes include:

• Distorted perceptions
• Impaired coordination
• Difficulty in thinking and problem solving
• Ongoing problems with learning and memory

Other signs of marijuana abuse, misuse and addiction include:

• Red, blurry, bloodshot eye
• Constant, mucus-filled cough
• Rapid heartbeat
• Hunger
• Dry mouth
• Anxiety, paranoia, or fear
• Poor memory
• Poor coordination
• Slow reaction time
• Loss of control

Marijuana Withdrawal Symptoms

Long-term drug abuse is associated with a number symptoms of marijuana withdrawal, which typically develop within one week of discontinuing use. Some of the most common symptoms of cannabis withdrawal include:

• Irritability, anger or aggression
• Nervousness or anxiety
• Sleep difficulty
• Decreased appetite or weight loss
• Restlessness
• Depressed mood
• Physical symptoms such as abdominal pain, shakiness/tremors, sweating, fever, chills or headache

Since many of these withdrawal symptoms mimic warning signs of other conditions and problems, an expert assessment by an addiction professional is necessary to determine whether marijuana withdrawal is the cause.

Marijuana Addiction Treatment

Treatment options or “rehab” for marijuana addiction is similar to treatment programs and protocols for addiction to alcohol and other drugs. Evidence-based therapies such as Twelve Step facilitation, cognitive-behavioral therapy, motivational enhancement therapy and other scientifically valid approaches can be effective addiction treatment options, depending on the individual’s situation, other drug abuse, and treatment needs.

How is heroin made?

Heroin is made in illegal drug labs, usually near places where opium poppies grow. It’s considered “semi-synthetic.” It starts out as morphine, one of the natural opiates found in the seed of the opium poppy plant, but has to go through a chemical process to become heroin.  

Drugmakers often mix heroin with other substances to make their product bulkier, cheaper, and stronger. This may include fentanyl, a powerful painkiller that’s often made and sold illegally. You can easily overdose and die on fentanyl, especially if you don’t know that it’s in the heroin you’re taking.  

Heroin may also be “cut” with:  

• Baking soda
• Powdered milk
• Sugar
• Starch
• Over-the-counter painkillers
• Powdered laundry detergent
• Caffeine 
• Quinine
• Antihistamines (to help with the side effect of itching)                                 

Who uses heroin?

In the U.S., use of pure heroin is highest on the West Coast and areas east of the Mississippi River. This includes cities such as San Diego and Seattle along with Boston, Baltimore, Washington, DC, Chicago, Minneapolis, and St. Louis. 

Other statistics about heroin include: 

• About 1.1 million people, or 0.4% of the U.S. population, may use heroin each year.
• A small percentage of kids in grades 8-12 report using heroin. 
• Around 1 million people aged 12 or older may have a heroin use disorder. 
• Almost 10,000 people die each year from an overdose that involves heroin. 

Black tar heroin. Like the name suggests, black tar heroin is dark and sticky. The color comes from how the drug is made. This less-refined process leaves behind impurities. Black tar heroin is sold most often in areas of the U.S. west of the Mississippi River. 

Heroin vs. morphine. They’re both opioids that can be highly addictive and misused. Though heroin comes from morphine, a legal drug used to treat severe pain and symptoms of other medical conditions, heroin is illegal and has no medical uses. 

How Heroin Is Used

Many people smoke or snort heroin. These methods are typically more common among people who use the drug in its pure form. Also called “chasing the dragon,” smoking heroin includes heating the drug and breathing in the fumes through a tube.

Most people who use heroin, including diluted forms, inject it into their veins. That’s the most dangerous way to take it because it’s easier to overdose and you can catch a disease from a dirty needle.

Right after you take heroin, you get a rush of good feelings, relaxation, and happiness. Then, for several hours, you may feel as if the world has slowed down. You may think and walk slowly. Some people who use heroin say you feel like you’re in a dream.

Heroin blocks your body from getting pain messages and slows your heart rate and breathing. If you overdose, you may stop breathing and die.

Many people start using heroin to deal with anxiety, worries, and other stressors. One study found that 75% of people who use heroin also had mental health conditions such as depression, ADHD, or bipolar disorder.

Why Are More People Using Heroin?

The number of people in the United States who use heroin has risen steadily since 2007.

A factor that played a role in the rise of heroin is the growing abuse of prescription painkillers such as oxycodone and hydrocodone, which are also made from the poppy plant and are chemically related to heroin. People who become dependent on or misuse these drugs may start looking for a stronger, cheaper high. Heroin is both. But it’s also more dangerous. There’s no way to know what you’re taking or how strong it is.

More than 1 million people have died since 1999 from a drug overdose. The U.S. opioid overdose death rate rose by 14% from 2020 to 2021. Some of these deaths happen because heroin is laced with other drugs, such as the powerful painkiller fentanyl. Fentanyl has become one of the leading contributors to overdose deaths in the U.S.

On the surface, humans’ brains share certain physical characteristics. Adult brains all weigh about three pounds and are about six inches in diameter. But every brain works in different ways and scientists are still trying to figure out how those differences account for people’s susceptibilities to becoming addicted to alcohol and drugs. Some people are attracted to addictive substances from the first time they use them and find they want more. For other people, drugs or alcohol register negatively from the beginning and they have little or no desire for more.

A person’s vulnerability to becoming addicted appears to depend primarily on three factors:

Genetics. If an individual has relatives with histories of drug or alcohol problems, it may indicate that they face a heightened risk of developing addictions themselves.

Environment. The circumstances of how a person grows up and lives their lives – including their families, friends, peer pressures, stresses and their inherent fears and insecurities – can influence the risk of an individual misusing alcohol and drugs.

Age of first use. Science has found that the earlier a person starts using drugs or alcohol, the greater their risk of developing addictions.

Scientists are still searching for a better understanding of the complexities of the brain and about the disease of addiction. But experts concede that there is not yet a way of knowing in advance how a person may react to addictive substances before they put them into their bodies, or what longer-term risks of addiction they face.

The brain and chemicals

There are two components to chemical addiction: the brain and the chemicals. Once an addictive substance is introduced into a person’s body and makes its way to the brain, the interaction that occurs will determine if problems may result.

Fundamentally, alcohol and drugs initially cause a reaction that the brain interprets positively. Most produce euphoria or a sense of relief from tension and stress. They can heighten a person’s self-confidence, well-being and feeling of being in control. They can bring on a welcome feeling of drowsiness and sleep.

But alcohol and drugs, if misused, can also create a host of physical and emotional side effects that are detrimental, if not disastrous, to the user. Past the obvious physical effects of misusing substances such as a person slurring their words or losing their balance, addictive substances have emotional and intellectual consequences, too. They can erode rational thinking to the point where behaviors that a person knows are dangerous – driving a vehicle while drunk, for example, or becoming physically or verbally abusive to others – seem to make sense. A brain under the influence of drugs or alcohol can be affected physically, psychologically, emotionally and spiritually by those addictive substances.

This is why it’s often said that drugs and alcohol “hijack” the brain.

Here are substances most often misused and abused:

Signs and symptoms

Sometimes, the signs and symptoms of an individual’s misuse of alcohol and drugs are easy to see: Unsteady gait, slurred speech, repeated absences from work, outbursts of belligerence or hostility, arrests for impaired driving, domestic violence incidents, serious health problems, etc.

Other times, individuals can go on for years successfully masking drug and alcohol problems from their closest friends, families, neighbors and employers. Perhaps, even from themselves. While the outward physical signs of these dependences can be harder to identify than in others, these individuals also suffer negative consequences because of their misuse of substances.

Since every brain is different and every brain reacts differently to different mind-altering substances, the signs and symptoms of an individual’s problem will be somewhat different.

But, in general, drugs and alcohol affect individuals in four chief ways: How they think (rationally), how they feel (emotionally), how they act (physically) and what they believe (spiritually). As a person’s use of drugs or alcohol deepens, the more the substances harm a person’s ability to function in all four areas.

People who develop dependencies on alcohol share several common signs and symptoms, which typically apply as well to those with drug-use problems:

• Tolerance. Over time, more and more of the substance is needed to produce the same effect as the body builds tolerance to the chemicals.
• Withdrawal. Anxiety, shakiness, insomnia, depression, fatigue and headaches are common signs of withdrawal when the body is deprived of substances it has become dependent on. For chronically heavy alcohol users, withdrawal without medical supervision can have life-threatening consequences.
• Loss of control. Use of alcohol and drugs despite an individual’s promise to themselves or others that they will not do it.
• Inability to stop. Efforts to stop and “stay stopped” fail.
• Neglecting other activities. Once-valued, positive experiences such as exercise, reading, hobbies and sports are abandoned in favor of using alcohol and drugs.
• Preoccupation with using substances. Thoughts about alcohol and drugs — obtaining them in sufficient quantities, anticipating their use, using them and recovering afterward — occupy increasing amounts of time, leaving less for more productive pursuits.

SAIR believes that the one warning sign for people to keep in mind about substance abuse – their own or others’ – is isolation. Isolation is the No. 1 factor that drives almost everything having to do with addiction. Virtually everyone who has become dependent on substances has withdrawn into themselves and into their own addictions. More and more, they have come to isolate themselves – emotionally, spiritually, even physically – from the things like family, friends, jobs, religion and other positive elements that defined their lives. This goes for both the person in the throes of a dependency problem and a sober person who is striving to avoid resuming alcohol or drug use.

Consequences and the ripple effect

The negative consequences of misusing alcohol and drugs are as varied as the individuals involved. In less-severe instances, they can be as relatively minor as saying something inappropriate to a co-worker or missing a child’s soccer match or music recital. In the most severe cases, substance abuse can lead to the loss of a job or custody of a child, destruction of a marriage, crime and incarceration, and death through accident, violence or disease.

Sooner or later, people who misuse or abuse alcohol and drugs almost always experience negative consequences. These tend to occur four ways:

• Relationships. The individual’s dealings with spouses, children, relatives, colleagues, friends and neighbors weaken or are wrecked as alcohol and drug use increases.
• Employment. Attention to jobs and careers wanes as a person’s interest in using substances deepens.
• Legal. More severe substance use seems to also lead individuals to become embroiled in legal problems like arrests for drinking-and-driving or domestic violence, debt and bankruptcy. Researchers say that up to 80 percent of Americans who commit crimes abuse alcohol or drugs and half the inmates of U.S. prisons and jails are clinically addicted to substances. Alcohol is linked to the commission of more violent crimes than the use of illegal drugs.
• Health. At the same time alcohol and drugs alter people’s behaviors, they also harm the health of individuals in a variety of well-documented ways. The Centers for Disease Control and Prevention estimates that about 88,000 Americans die each year due to the direct health consequences of excessive alcohol intake. However, an expanded study published by JAMA Network Open late in 2022 found that when the broader effects of drinking — such as alcohol-related murders and accidents — were factored in, an average of about 140,000 Americans died annually between 2015-19 from causes attributable to the consumption of alcohol. Among adults ages 20 to 49, the study found that 1 in 5 deaths were attributable to alcohol. There are also about 63,500 drug overdose deaths in the United States, according to the National Center for Health Statistics. A range of serious related health problems, from hypertension for heavy drinkers to neurological problems for drug users, are also associated with substance misuse and abuse.

While the consequences of misusing alcohol and drugs are usually negative, that does not mean they can’t be turned into a positive.

Consequences often provide the motivation people need to get help.

The presence or the threat of consequences can serve as a sign that alcohol or drugs are becoming a serious problem. Consequences can sometimes “scare” people into addressing their problems, as can the realization that they risk worse problems if they do not address their continued use of substances.  

But the individual using alcohol or drugs is not the only person affected. The “ripple effect” of alcohol and drugs often extends to the person’s spouse, children, grandchildren, parents, grandparents, siblings, friends, neighbors as well. Sometimes, the effects of a person’s substance abuse can be every bit as damaging emotionally, spiritually and financially to those close to the addict as it is to the addict themselves.

It’s often left to the person who is not in the throes of a substance problem to pick up the slack for those who are. They assume a greater share of child or parent care, home maintenance, money-earning and the other responsibilities that an addict becomes less and less able or inclined to do.

It is SAIR’s belief that substance abuse poses a problem that all people have a shared responsibility to help solve. It is the personal responsibility of the person with an alcohol or drug problem to seek help once it is apparent they need it. It is the responsibility of those close to the addict to help them do so. It is the responsibility of everyone to educate themselves about addiction and how to prevent it.