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Short-term memory problems

Severe anxiety, including fear that one is being watched or followed (paranoia)

Very strange behavior, seeing, hearing or smelling things that aren't there, not being able to tell imagination from reality (psychosis)

Panic

Hallucinations

Loss of sense of personal identity

Lowered reaction time

Increased heart rate (risk of heart attack)

Increased risk of stroke

Problems with coordination (impairing safe driving or playing sports)

Sexual problems (for males)

Up to seven times more likely to contract sexually transmitted infections
than non-users (for females) 22,32 & 33

LONG-TERM EFFECTS

Decline in IQ (up to 8 points if prolonged use started in adolescent age)

Poor school performance and higher chance of dropping out

Impaired thinking and ability to learn and perform complex tasks

Lower life satisfaction

Addiction (about 9% of adults and 17% of people who started smoking as teens)

Potential development of opiate abuse

Relationship problems, intimate partner violence

Antisocial behavior including stealing money or lying

Financial difficulties

Increased welfare dependence

Greater chances of being unemployed or not getting good jobs.33

"I started using on a dare from a best friend who said that I was too chicken to smoke a joint and drink a quart of beer. I was fourteen at that time. After seven years of using and drinking I found myself at the end of the road with addiction. I was no longer using to feel euphoria, I was just using to feel some semblance of normality. "Then I started having negative feelings about myself and my own abilities. I hated the parano ia [suspicion, distrust or fear of other people]. I hated looking over my shoulder all the time. I really hated not trusting my friends. I became so paranoid that I successfully drove everyone away and found myself in the terrible place no one wants to be in-I was alone. I'd wake up in the morning and start using and keep using throughout the day." -Paul

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Short- & Long-Term Effects of Marijuana - Negative Side Effects of Weed - Drug-Free World

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Short-term memory problems Severe anxiety, including fear that one is being watched or followed (paranoia) Very strange behavior, seeing, hearing or smelling things that aren't there, not being able to tell imagination from reality (psychosis) Panic Hallucinations Loss of sense of personal identity Lowered reaction time Increased heart rate (risk

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Aubri John

Aubri John has been a contributing researcher and writer to online physical and mental health oriented journals since 2005. John publishes online health and fitness articles that coincide with her licensed clinical skills in addictions, psychology and medical care. She has a master's degree in clinical social work and a Ph.D. in health psychology.

Marijuana is a plant with psychoactive (mind-altering) properties that targets the central nervous system and alters the brain's ability to communicate between neurons, which is the body's information processing system. Although marijuana comes from a natural plant source, the potency of the drug significantly alters the way a normal brain functions. Tetrahydrocannabinol (THC) is the active ingredient in marijuana that highly affects the brain regions of the cerebellum, hippocampus, cerebral cortex, nucleus accumbens and basal ganglia. THC also moderately affects the hypothalamus, amygdala and brain stem.

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The THC in marijuana attaches to naturally produced cannabinoid receptors in the brain and changes how these receptors process information. The natural regulating mechanisms become blocked and produce an overflow of chemicals, causing the disruptions of regular brain functioning. Areas highly affected by the drug include the cerebellum and basal ganglia. These areas are responsible for movement, coordination, balance and body control. The cognitive system, including the hippocampus and cerebral cortex, are areas responsible for learning, memory and thinking. Cognitive functions are overloaded by THC during marijuana use and create lapses in thought process, time delay and loss of memory. Research further indicates that there are long-term affects to these areas of the brain when marijuana is used on a regular basis over time.

Marijuana use alters emotions, response time, arousal and perceptions of pain. Depending on quantity used, the THC can modify the hypothalamus' ability to regulate body functions such as temperature and reproductive function. The amygdala is the brain region responsible for emotional response; when someone is intoxicated on marijuana, this area of the brain tends to show slow or blunted reactions to situations that might normally produce fear or excitability. Pain receptors in the brain are also changed with marijuana use. In many cases, this could be perceived as a positive function of marijuana, however, it could also be unhealthy as the body will not respond to pain as it should in order to withdraw from the pain- stimulating source.

The cannabinoid receptors are activated by neurotransmitters in the brain. The naturally occurring cannabinoids referred to as endocannabinoid ligands include anandamide, 2-arachidonoyl glycerol, N-arachidonoyl-dopamine, and virohamine. These cannabinoids are all similar in chemical makeup to the active ingredient in marijuana. However, when paired with THC from marijuana use, the natural neurotransmitters do not function in the same capacity and are unable to provide the correct information to the different brain regions in order for the body to respond in a normal manner to brain commands. The affect marijuana use has on the brain is a complex yet significant process that ultimately alters how the brain and body will function for a person over time.

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What Parts of the Brain Are Affected From Marijuana Use?

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Marijuana is a plant with psychoactive (mind-altering) properties that targets the central nervous system and alters the brain's ability to communicate between neurons, which is the body's information processing system. Although marijuana comes from a natural plant source, the potency of the drug significantly alters the way a normal brain...

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In part 1 of what marijuana really does to your brain, we traced the discovery of the cannabinoid receptor. Finding the receptor is the first step in determining how smoking causes a high. The next step is to figure out where cannabinoid receptors are and what they're doing.

In 1989, the year after the cannabinoid receptor was discovered, Miles Herkenham led a group of researchers at the National Institute on Mental Health to find out where cannabinoid receptors were located in the brain. He first collected brains of three deceased humans whose bodies had been donated to science. He sliced the brains so he could quantify how many cannabinoid receptors were in each region. Then he labeled CP-55,990, the same synthetic version of THC used to discover the cannabinoid receptor, with a radioactive form of hydrogen atom called tritium. He squirted the radio-labeled CP-55,990 onto the brain slices and then took pictures of them using film that was sensitive to tritium. He found the receptor in many parts of the brain, but they were most densely packed in the hippocampus, amygdala, striatum and cerebellum. As we will see, it is not surprising that Herkenham identified these four regions-they are responsible for many of the functions that marijuana influences.

1. Impaired memory

Marijuana may not destroy memories, but it can prevent you from forming new ones. One way researchers test memory is by reading a list of words to someone and later asking them to repeat the list or recognize the original words from a new list. A number of studies have shown that when the researcher read the words before participants smoked, the participants remembered the words just as well if the joint contained marijuana or a placebo. If the researcher read the words after participants smoked, however, they remembered less if the joint contained marijuana. Since we know that marijuana can disrupt memory, the likely target in the brain is the hippocampus, the region most linked to memory formation. When cannabinoid receptors in the hippocampus are activated, they interfere with a cellular process called long term potentiation, a long-lasting booster of cross-talk between neurons. Studying for a test high may not be the best idea because THC disrupts the hippocampus' cellular process of creating new memories.

2. Reduced anxiety

A group of multiple sclerosis patients were given marijuana as an experimental treatment, and they reported a consistent side-effect. 89 percent reported reduced anxiety after smoking. Since regular marijuana users tend to have higher than normal anxiety levels, they may smoke in part to ease their worries. The brain produces a chemical, anandamide, that targets the cannabinoid receptor, the body's own form of THC. Anandamide gets deactivated by an enzyme called FAAH, or fatty acid amide hydrolase. A group of researchers at the National Institute on Alcohol Abuse and Alcoholism injected a chemical into the amygdala region of mice brains to block FAAH from deactivating anandamide, which allows it to have longer-lasting effects. The amygdala has a high concentration of cannabinoid receptors and is the brain region most associated with fear and anxiety. When FAAH was blocked in the amygdala, mice were less afraid of cues previously paired with shocks. The authors found a similar effect in humans. People with a gene that produces a lower functioning version of FAAH, and who consequently have more anandamide, were quicker to learn that a threatening cue was harmless. Marijuana may reduce anxiety because THC binds to cannabinoid receptors in the amygdala, reducing the brain's threat response.

3. Disrupted motor control

The greatest concentration of cannabinoid receptors reside in the striatum and substantia nigra, parts of the brain responsible for coordinating movement. These brain regions also deteriorate in Parkinson's Disease, and like Parkinson's, one of the signature effects of THC is poor motor control. That's partly why marijuana, like alcohol, compromises driving ability. A recent study from an emergency room in Canada found that 20 percent of driver's injured in car accidents had THC in their blood, even though, according to UN estimates, only 4 percent of the population smoked in the past year. A group of researchers asked the marijuana users about their driving habits and determined that the drivers were 4x as likely to crash when they were high compared to when they drove sober at the same time of day.

4. Stoked appetite

At Seattle's 2013 Hempfest, police wanted to remind attendees of the state's pot laws. To make sure Hempfesters got the message, they attached the rules to bags of Doritos. They capitalized on a long-held belief about marijuana: it boosts desire to eat junk food, also known as the munchies. A 2001 study in the journal Nature offers an explanation. The study found that activating cannabinoid receptors in a part of the brain called the hypothalamus could trigger the release of leptin and neuropeptide Y, hormones that stimulates appetite. You don't need much coordination to down a handful of Doritos.

5. Elevated heart rate

"I vaped a bunch of weed last night and I counted my heart rate at 120 beats per minute," said a user on the message board at cannabis.com. Increased heart rate is a common effect of marijuana, often leading to a 50 percent increase in beats per minute. Peak heart rates usually occur 15 minutes after peak THC concentrations. Studies have found that the risk for heart attack is 4.8 times higher in the hour after smoking marijuana compared to the hour before (4.8 times a small number, however, is still a small number). A group of researchers at the National Institute on Drug Abuse led by Marilyn Huestis tested whether the brain's cannabinoid receptors caused the elevated heart rate. They gave some people a chemical called SR141716 that blocks the brain's cannabinoid receptors, and other people received a placebo. They then had all participants smoke a joint of marijuana. The group that got a placebo had an average increase of 30 heart beats per minute after smoking. The group that got SR141716 only increased their heart rate by 10 beats per minute. The group who took SR141716 also reported feeling less high than the group smoking marijuana without the antagonist. Based on this evidence, the increase in heart rate after smoking marijuana likely occurs when THC activates cannabinoid receptors in the brain.

6. Altered sleep

This is the effect with the least solid evidence. According to pot critic William Breathes, some strains of marijuana help him fall asleep. But research into this has produced mixed findings, with some evidence suggesting that high THC concentrations can even prevent sleep, inducing restlessness instead. The subjects in that study did not have a history of heavy cannabis use, so the effect on sleep may have to do with tolerance. One effect on sleep seems fairly consistent: THC reduces the amount of time a person spends in rapid eye movement sleep, the phase of sleep where most dreaming occurs.

7. Reduced pain

Dating back over 1,500 years, one of the earliest recorded uses of marijuana was to numb pain during surgery. They didn't have microscopes to look at nerve cells back then, but they were already observing something that modern neuroscientists have only explained in the past 20 years. Many of the nerve cells in our body that carry pain signals have cannabinoid receptors, from the body to the spinal cord up into the brain. When researchers activated the cannabinoid receptors in the spinal cords of rats, they would leave their tail on a hot plate for longer before moving it, suggesting that it didn't hurt as much. One of the brain's main pathways of pain signals, the periaqueductal gray region, is heavily populated with cannabinoid receptors. Similarly, activating these receptors makes rats less sensitive to pain. Marijuana's ability to numb pain is one of the reasons some patients seek it to deal with cancer treatment.

Those are 7 short term effects of THC. Come back for Part 3 to find out about the long term effects of marijuana on the brain.

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7 Short-Term Effects of Marijuana on the Brain

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In part 1 of what marijuana really does to your brain, we traced the discovery of the cannabinoid receptor. Finding the receptor is the first step in determining how smoking causes a high. The next step is to figure out where cannabinoid receptors are and what they're doing.

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The intensity and character of marijuana's effects varies with strain, preparation, and method of consumption. This article discusses the options and their pros and cons so you can determine which cannabis type and form might be right for you.

Strains of Weed

Like many plants, cannabis comes in many strains. Marijuana strains are generally categorized as sativa, indica, or a hybrid of both.

Sativa strains tend to produce an energetic, euphoric buzz.

Indica strains can be calming and relaxing.

Hybrid strains are a blend of the two. Most modern strains are hybrid to some degree.

Forms of Weed

Cannabis is available in several forms:

Flower

Often simply called weed or pot, this is the unprocessed form of cannabis. Weed consists of the dried leaves and buds of the female Cannabis sativa and Cannabis indica plants.

It has a very pungent and recognizable odor, both in its unburnt state and while being smoked. This odor is quite unlike kitchen herbs, although weed is sometimes "cut" (mixed) with benign kitchen herbs such as oregano and parsley when sold in the underground market.

Weed is commonly smoked in hand-rolled cigarettes, known as joints. The lumpy texture of weed can be felt through the tobacco rolling paper. This is one of the characteristics that can differentiate a joint from a hand-rolled tobacco cigarette.

Hashish and weed can be mixed with rolling tobacco, which is a soft, moist, sticky tobacco preparation designed for hand-rolling. It may also be mixed with the dry tobacco from deconstructed cigarettes. This mixture is referred to as a "spliff".

Weed, hashish, and hashish oil can be smoked in pipes, water pipes, and bongs, or mixed with tobacco and smoked in a chillum. Some young adults have also used e-cigarettes to inhale marijuana through "vaping."

Pros: Easily accessible in legal states, can grow it yourself (if state law allows), a wide variety of strains and potencies

Cons: Not a good choice for somebody with lung issues or who does not want to inhale a lot of smoke

Edibles

Marijuana can also be taken orally and is often cooked into food. In this form, it is commonly called edibles. A classic way to eat marijuana is in the form of brownies or cookies. However, marijuana can be added to many types of food, just like an herb, and may even appear in candy.

It is added to food products through a process known as infusion in which activated cannabis compounds are added into an edible. This is often done through a process known as decarboxylation, which involves physically altering the chemical structure of cannabis compounds by applying heat. The decarboxylate process is what makes cannabis psychoactive.

The next step is to infuse the decarboxylated cannabis into butter or oil, and then add the infused fat into an edible product.

With edible forms of marijuana, it takes longer to feel the psychoactive effects and it can be quite potent.

Anecdotal observations suggest that edibles may be helpful for conditions such as pain, nausea, epilepsy, and mental health conditions such as PTSD and depression. However, overconsumption of edibles is linked to motor impairment, cognitive problems, agitation, anxiety, vomiting, and sedation.

Pros: Avoids the negative health effects of smoking marijuana and the effects may last longer than smoked cannabis.

Cons: It takes longer to metabolize ingested cannabis, which can make it easy to accidentally consume too much.

Concentrates

Cannabis concentrates are produced by distilling certain parts of the cannabis plant. Doing this leads to a higher concentration of cannabinoids and terpenes.

Some of the processes that are used to produce cannabis concentrates include dry processing, dry ice processing, water-based processing, pressure/heat processing, and the use of flammable or non-flammable solvents. Once produced, a concentrate may look like a liquid wax, a soft solid, or a hard solid.

These products can then be consumed in a variety of different ways depending on the form of the concentrate. Dabbing is one popular way to consume cannabis concentrates.

Dabbing

Dabs are also referred to as shatter, wax, budder, amber, and honeycomb. They are concentrated forms of butane hash oil and contain high levels of THC. Dabs can be administered by heating the product and then inhaling it or by placing hash oil in a vape pen.

Wax, Shatter, Oils

Shatter is a translucent, glasslike concentrate. It can be used by putting it on a hot surface and inhaling the smoke. Wax is a malleable substance with a butter-like texture that can be placed in a bong or pipe and smoked. Oil is a liquid cannabis concentrate that can be consumed with a vape pen, taken sublingually under the tongue, added to edibles, or placed in a capsule.

Capsules

Concentrates can also be made into capsules to be swallowed. Like edibles, capsules must be absorbed by the stomach and metabolized to have an effect.

Tinctures

A tincture is a cannabis extract that is combined with another substance, often alcohol. These products are often ingested by putting a few drops under the tongue, but the tincture can also be added to foods and beverages.

Hash

Hashish, or hash for short, is a preparation of marijuana made from the resin of the Cannabis sativa or Cannabis indica plant. The resin is dried into blocks of hashish, producing an oily, solid substance. Hash is often warmed, crumbled, and rolled together with tobacco. It may also be smoked in a pipe, bong, or chillum.

Pros: Concentrates usually have high potency and better flavor. They are also often easier to use discretely.

Cons: Concentrates are usually more expensive than other forms of marijuana. Some potentially dangerous side effects may occur including anxiety and hallucinations. Producing concentrates can be potentially dangerous, especially when using combustibles.

Distillate

Distillate is a golden, runny oil that is created by refining cannabis resin to isolate the desirable cannabinoid compounds and remove unwanted material. These products can then be used in vape cartridges, but they can also be added to other products including topicals and edibles.

Rick Simpson Oil

One type of distillate is known as Rick Simpson oil (RSO), named after its creator. This type of oil contains higher levels of THC than other forms and is purported to offer benefits for conditions such as skin cancer, asthma, inflammation, depression, and infections.

Some research has found that THC and CBD extracts may be helpful when used as a treatment alongside radiation therapy; however, more research is needed.

Pros: Because of how they are made, distillates can contain very high concentrations of cannabis compounds. They tend to have a lighter smell and taste, which some people may prefer.

Cons: Distillates are a type of cannabis isolate, so they might not contain other cannabinoids that can create "the entourage effect." This refers to the compounded benefits of consuming different cannabinoids together.

Frequently Asked Questions

How long does marijuana stay in your system?

How long marijuana remains in your system depends on a variety of factors including how much you used and your physiology. For example, after using marijuana one time, it may be detectable in urine for up to 13 days. If you use marijuana heavily, it may be detected in urine and hair for up to 90 days.

Yes, marijuana can be addictive. While most people who use marijuana will not become addicted, around 30% will develop a marijuana use disorder.

How long does it take for edibles to kick in?

Edibles take longer to begin working than inhaling marijuana, but the effects last longer. One study found that when taking THC orally, such as in an edible, it can take between 30 and 90 minutes for the effects to kick in.

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

National Institute on Drug Abuse. Marijuana concentrates. DrugFacts.

By Elizabeth Hartney, BSc, MSc, MA, PhD
Elizabeth Hartney, BSc, MSc, MA, PhD is a psychologist, professor, and Director of the Centre for Health Leadership and Research at Royal Roads University, Canada.

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Weed (cannabis) potency and effects vary with strain, form, and consumption method. Learn about the options for cannabis consumption, along with the pros and cons of each.

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The cannabis is shown in certain studies to be very likely connected to psychosis which is a mental disorder that includes a mental disconnection from reality. This includes hallucinations, delusions, and agitation. Marijuana may also come along with other disorders such as depressive disorder or schizophrenia.

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- has the ability to possibly prevent you from making new memories
- can reduce anxiety
- can cause elevated heart rate
- reduced pain

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Marijuana is normally used through cigarettes or pipes (dry or water). People who use marijuana would inhale smoke from pipes and feel it's effects within minutes of doing so. Being exposed to one pipe's smoke is found to be equal in exposure to carcinogenic chemicals as about four to five cigarettes.

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Commonly used street names for marijuana may include:
- weed
- pot
- bomber
- giggle smoke
- joy smoke
- gasper
- herb
- etc.
(there are way too many street names for marijuana to list here).

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Marijuana is a greenish-gray mixture of the dried, shredded leaves of the Cannabis sativa. Marijuana can be found in many different forms such as weed (looks like some sort of herbal mixture), hashish (sort of shaped like a stock cube and varies in colors sometimes), pipes (looks somewhat like the pipe that Sherlock Holmes is sometimes seen with), and many more.

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Marijuana can cause The THC (tetrahydrocannabinol) in marijuana attaches to naturally produced cannabinoid receptors in the brain and changes how these receptors process information.