how to tell if someone smokes weed

Dialing down the noise: What are the signs someone is addicted to weed?

Right out of the gate, asking about the signs someone is addicted to weed is going to cause a firestorm.

We get it. Marijuana has a healthy contingent of defenders, to the point that, at times, it’s difficult to have a civil conversation about it. Like any other mind- or mood-altering substance, discussing the potential for addiction to marijuana isn’t a value judgment about the substance itself. It is, like any other drink or drug, an assemblage of chemical compounds that affects everyone in different ways.

In the case of marijuana, thousands of individuals partake with absolutely no consequences, meaning it never develops into a problem. In fact, marijuana has a great many advocates who tout its benefits as a holistic alternative to pharmaceutical medicine, and there are indeed some scientific studies that have demonstrated its medicinal effectiveness.

Addiction, however, is a process that takes place in the brain of afflicted individuals, many of whom are biologically or genetically predisposed to it regardless of what substances they consume — from heroin to cocaine to alcohol to, yes, marijuana. The signs someone is addicted to weed may not lead them to the bitter ends of other addictive substances, but the entire concept of recovery is built around quality of life.

In that regard, marijuana can have a negative impact and lead to problems that worsen the quality of life for those who become addicted to it rather than enhancing it, as it may do for some. Those individuals shouldn’t be shamed for wanting to do something about it.

So how does marijuana affect the brain? When did we, as a species and a culture, develop an affinity for it? And what ARE the signs someone is addicted to weed? Let’s dive in.

Weed 101: What Is It?

Pot, reefer, weed, grass, ganja, herb, Mary Jane … marijuana has been saddled with a number of slang terms over the years, but for the sake of this particular blog, they all come down to one thing: cannabis, and specifically the chemical compound delta-9 tetrahydro-cannabinol, commonly referred to as THC. Cannabis is the name of the plant from which weed comes — specifically, cannabis sativa, which “grows wild in many of the tropical and temperate areas of the world. It can be grown in almost any climate, and is increasingly cultivated by means of indoor hydroponic technology,” according to the University of Washington’s Alcohol and Drug Abuse Institute [1].

THC is the chemical compound that gives cannabis consumers the “high” that they desire. While there’s been an explosion of THC-related products as marijuana has been legalized in a number of states, the three main forms of cannabis, according to the University of Washington, are “marijuana, hashish and hash oil. Marijuana is made from dried flowers and leaves of the cannabis plant. It is the least potent of all the cannabis products and is usually smoked or made into edible products like cookies or brownies. Hashish is made from the resin (a secreted gum) of the cannabis plant. It is dried and pressed into small blocks and smoked. It can also be added to food and eaten. Hash oil, the most potent cannabis product, is a thick oil obtained from hashish. It is also smoked.”

Granted, those three are not the end-all, be-all of products derived from cannabis, and we’ll get into some of the more modern consumables later on. The focus here is on THC, which is the chemical that can pose problems. Those who show signs someone is addicted to weed are really addicted to the effects THC has on the brain.

So how does it affect the brain? For starters, THC mimics a naturally occurring brain chemical called anadamide, according to the National Institute on Drug Abuse (NIDA) [2], which function as neurotransmitters that relay messages between nerve cells: “They affect brain areas that influence pleasure, memory, thinking, concentration, movement, coordination, and sensory and time perception. Because of this similarity, THC is able to attach to molecules called cannabinoid receptors on neurons in these brain areas and activate them, disrupting various mental and physical functions.”

These cannabinoid receptors, according to the website [3], “exists in brain areas that are critical for learning, memory, pain perception, and reward processing,” and the introduction of THC causes a number of things to happen, the NIDA points out:

  • Because it affects the hippocampus and the orbitofrontal cortex, “areas that enable a person to form new memories and shift his or her attentional focus … using marijuana causes impaired thinking and interferes with a person’s ability to learn and perform complicated tasks.”
  • THC also affects normal functioning in the cerebellum and the basal ganglia, “brain areas that regulate balance, posture, coordination, and reaction time.”
  • Finally, through those natural cannabinoid receptors, THC “also activates the brain’s reward system, which includes regions that govern the response to healthy pleasurable behaviors such as sex and eating. Like most other drugs that people misuse, THC stimulates neurons in the reward system to release the signaling chemical dopamine at levels higher than typically observed in response to natural stimuli. This flood of dopamine contributes to the pleasurable ‘high’ that those who use recreational marijuana seek.”

Signs Someone Is Addicted to Weed: A Brief History

Again, it’s important to frame this conversation as one about a certain segment of the population who develop a problem with marijuana. If you’re seeking signs someone is addicted to weed, it’s easy to take every physical symptom as a harbinger of doom, but ancient civilizations have used cannabis “in medicine, magic, religion and recreation,” according to High Times magazine [4], the authority on all things weed since 1974. Some of those civilizations, High Times writer Alan Sumler detailed in 2017, included:

  • The Assyrians and Babylonians of Mesopotamia, where “it was used for treating depression, as well as in different medical recipes. Under the name kunubu, it was one of the ingredients in their religious incense, which they traded with Egypt and Judaea.”
  • In Bactria — what’s now Afghanistan and Turkmenistan — “Zoroastrian priests prepared the plant as an ingredient in their religious drinks.”
  • In ancient India, cannabis was called bhang and ganjha (twisted rope). Their pharmaceutical texts (ca. 1600 BCE) prescribe the plant for treating anxiety, among other common ailments.”
  • Cannabis and hemp were present in ancient Egypt, and in nearby Judaea, “cannabis appears as one of the ingredients in holy incense and anointing oil under the name kaneh bosm.”
  • “The ancient Greek historian Herodotus (5th century BCE) wrote about the nomadic Scythians and their fumigation of cannabis flowers.”
  • The Subeixi, which flourished in the contemporary Chinese province of Xinjiang, “ancient cannabis remains of 16 intact female plants were found in a grave, lain across the deceased body as a burial shroud. Another grave in a nearby cemetery contained a little under two pounds of processed and cut cannabis.”
  • “The Roman naturalist Pliny (23-79 CE) mentioned cannabis in several passages, including medical usages.”

By the 16 th century, cannabis had expanded westward, according to the DEA Museum [5], “where Spaniards imported it to Chile for its use as fiber” circa 1545. “In North America cannabis, in the form of hemp, was grown on many plantations for use in rope, clothing and paper.” It was in the 19 th century, according to [6], that cannabis began to appear as a component of Western medicine when “Sir William Brooke O’Shaughnessy, an Irish doctor studying in India, found that cannabis extracts could help lessen stomach pain and vomiting in people suffering from cholera. By the late 1800s, cannabis extracts were sold in pharmacies and doctors’ offices throughout Europe and the United States to treat stomach problems and other ailments.”

In the early part of the 20 th century, however, marijuana began to be seen in a different light. According to Eric Schlosser, writing in 1994 for the publication Atlantic [7], “The political upheaval in Mexico that culminated in the Revolution of 1910 led to a wave of Mexican immigration to states throughout the American Southwest. The prejudices and fears that greeted these peasant immigrants also extended to their traditional means of intoxication: smoking marijuana.” Law enforcement and government officials began to demonize weed, and headlines like this 1925 one in The New York Times [8] were common: “Mexican, Crazed by Marihuana, Runs Amuck With Butcher Knife.”

In 1937, the federal government passed the Marijuana Tax Act, “the first federal U.S. law to criminalize marijuana nationwide,” according to [6]. “The Act imposed an excise tax on the sale, possession or transfer of all hemp products, effectively criminalizing all but industrial uses of the plant.” That was repealed in 1970 with the introduction and passage of the Controlled Substances Act, which “listed marijuana as a Schedule I drug — along with heroin, LSD and ecstasy — with no medical uses and a high potential for abuse. It was identified in anti-drug programs like D.A.R.E. (Drug Abuse Resistance Education) as a ‘gateway drug.’”

States began to push back against such a draconian measure in 1996, when California, which passed the “Compassionate Use Act of 1996, became the first state to legalize marijuana for medicinal use by people with severe or chronic illnesses.”

As of 2020, according to Esquire magazine [9], there are 11 states (plus the District of Columbia) that have legalized weed (Alaska, California, Colorado, Illinois, Maine, Massachusetts, Michigan, Nevada, Oregon, Vermont and Washington) for personal use, and another 22 have legalized it for medical use only. Although still technically considered a Schedule 1 drug at the federal level, it remains completely illegal in 17 states: Alabama, Georgia, Idaho, Indiana, Iowa, Kansas, Kentucky, Mississippi, Nebraska, North Carolina, South Carolina, South Dakota, Tennessee, Texas, Virginia, Wisconsin and Wyoming.

It may seem like a joke to ask about the signs someone is addicted to weed, but it's important to remember: Addiction isn't necessarily about the substance.

How Do You Know If Someone Is Addicted to Weed?

Steven Gans, MD is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital.

If your friend smokes weed and you are concerned that it is a problem, talk to them about it. A clear sign that recreational substances, such as alcohol or marijuana, have become an addiction is when family life, daily activities, and ability to work is impeded, and/or they can’t stop using the substance even though they want to quit.

Is Marijuana Addictive?

Marijuana addiction is uncommon and can only be diagnosed in severe cases. Only a small percentage of users will develop what is known as a marijuana use disorder. The number rises significantly for those who started using weed in their teens, according to the National Institute on Drug Abuse (NIDA).   If your friend uses pot occasionally, they likely do not have an addiction to marijuana.

Marijuana Use Disorder

Rather than use the term “addiction,” health professionals prefer the term “marijuana use disorder.” The NIDA estimates that about 30% of marijuana users may have some degree of marijuana use disorder.  

Marijuana Dependence

If your friend frequently uses marijuana and experiences withdrawal symptoms upon stopping the drug, they may be considered to have marijuana dependence. Marijuana withdrawal symptoms are typically mild, peak within the first week after quitting, and may last up to two weeks. Symptoms include:  

  • Irritability
  • Trouble sleeping
  • Decreased appetite
  • Restlessness​

Marijuana Effects on the Adolescent Brain

Research has examined how marijuana affects teens. Some studies suggest that teenagers who use marijuana frequently may experience short-term effects such as problems with memory, learning, coordination, and judgment.  

There are also long-term effects. Some studies suggest an association between regular marijuana use in teens and “altered connectivity and reduced volume of specific brain regions.”     But other studies “have not found significant structural differences between the brains of users and non-users.”  

A large cohort study followed nearly 4,000 young adults over a 25-year period into mid-adulthood. It found that although cumulative lifetime exposure to marijuana is associated with lower verbal memory test scores, exposure did not affect other cognitive abilities like processing speed or executive function.  

Studies have found that frequent use of marijuana as a teenager can be associated with an average IQ loss of eight points that were not recoverable after quitting. However, the same use in adults showed no reduction in IQ. The research data suggests marijuana’s strongest long-term impact is on young users whose brains are still developing.  

Marijuana As a Gateway Drug

Marijuana is not generally considered a “gateway drug” because the majority of weed users do not go on to use harder, addictive substances, including cocaine and heroin. Social environment might be a more critical factor in determining someone’s risk for trying harder drugs.  

If someone is more vulnerable to getting involved with addictive substances, they are more likely to start with substances that are more readily available, such as alcohol, tobacco, or marijuana. People who have social interactions with other substance users are more likely to try other drugs.  

If your friend uses weed and it does not interfere with work, family life or daily activities, it is likely that your friend does not have an addiction.