Is Weed Bad for Your Brain
When you have a medical condition with challenging symptoms, it can impact every area of your life. If you are struggling with chronic symptoms daily, it can disrupt the things that matter—doing activities you love, your job, relationships, and more.
Ten years ago, medical cannabis was not a legal option for patients. Some states have legalized clinical-grade cannabidiol (CBD) for patients by prescription only. But today, almost every state has a medical cannabis program. And that gives patients a new approach they can try to help make health symptoms more manageable.
Medical cannabis can be very effective as part of a doctor-supervised treatment plan. Every month, we talk to thousands of patients who feel that their lives have been transformed by medical marijuana. Most of them did not experience relief from symptoms until they got their medical card.
Doctor-supervised cannabis means access to an experienced practitioner who can help you decide whether cannabis is a safe choice. But some people wonder if using medical marijuana for an extended period can result in side effects.
Is long-term use of cannabis bad for your brain? Let’s take a closer look at what clinical studies have said and the symptoms you should watch out for.
What Happens to Your Brain After You Smoke Marijuana?
The cannabis plant has been used medicinally for centuries. And if you regularly use medical cannabis, you already know about the psychoactive effects of marijuana. But what happens behind the scenes in your brain and body after cannabis consumption?
Unlike consuming alcohol or other drugs with molecules foreign to our brains, cannabis molecules are familiar. That is because the brain has cannabinoid receptors already built in.
Activated CB1 receptors in the brain have the effect of changing the way signals are communicated. Cannabis can reduce pain signals and enhance pleasurable feelings. While also increasing spatial impairments and problems with verbal memory.
Cannabinoids are highly lipophilic. That means they are attracted to and easily absorbed by any cells that have fat content. That also means that THC can remain in adipose (fat) tissue for an extended period.
The overall bioavailability of THC averages around 30%. Oral THC taken as edibles, capsules, or tinctures averages between 4% to 12% bioavailability. But the absorption rates are variable depending on factors like health, hydration, the potency of the cannabis used, and more.
Anandamide and THC Twinning in the Human Brain
The human brain thinks THC is Anandamide. It is a neurotransmitter that binds to our cannabinoid receptors. This is where feelings of calmness, low-to-no anxiety, and happiness come from. Anandamide is called the “bliss” molecule.
Anandamide are specialized neurotransmitters that work on neurons that have just fired (or relayed a signal). After a neuron has “fired” off a signal, it becomes unresponsive for a short period. This allows the brain to process actions, thoughts, memories, and more in a calm and organized manner.
Cannabinoids can be a monkey wrench in that process and speed things up. The cannabinoids work to reduce the refractory (resting) period of neurons. This causes the sensation of a cerebral “head high.” And it is also the reason why you may fixate on an object or idea. Or why your cat’s whiskers become utterly fascinating when you are high.
While those neurons keep firing, you may transfix on another idea or object. Cannabinoids also affect hormones like dopamine and norepinephrine in your brain. That can lead to relief of pain and anxiety and amplify pleasurable experiences. Making your bowl of cereal even more delicious than normal; hence “the munchies.”
The Endocannabinoid System and Brain Functioning
Inside your body, the endocannabinoid system regulates essential functions, including sleep, brain functioning (cognition), inflammation, and energy metabolism. Different neurotransmitter systems (dopamine, glutamate, GABA) send and receive messages through cannabinoid receptors.
There are cannabinoid receptors all over your body, but the brain has the highest concentration of CB1 and CB2 receptors. Both delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) can cause disturbance within the endocannabinoid and central nervous system with frequent cannabis use.
Several clinical studies suggest that hippocampal neurons are depleted (volume is reduced) in long-term cannabis users. The most significant changes were recorded with patients who used higher potency cannabis with little to no cannabidiol (CBD) content.
There are direct and indirect methods where cannabis use can threaten brain health, particularly if the individual uses higher volumes and potencies of medical marijuana over an extended period.
Taking cannabis can result in both hypertension (elevated blood pressure) and hypotension (lowered blood pressure). The fluctuation in your blood pressure after you have taken medical marijuana varies, depending on several factors.
It should be no surprise that Sativa strains of cannabis can elevate your blood pressure. Sativa cannabis increases the heart rate for a short period. Some clinical studies suggest active cannabis use may increase systolic blood pressure but not diastolic BP.
For many people, the changes in blood pressure with marijuana use are marginal. But if you have underlying cardiovascular problems, difficulty regulating hypertension, or hypotension, talk to your doctor about the risks of cannabis use. Medical marijuana could make symptoms of high or low blood pressure worse.
How Does High Blood Pressure Impact Your Brain?
Hypertension or high blood pressure can cause serious health problems and increase your risk for potentially life-threatening cardiovascular issues. Some of the risks associated with uncontrolled hypertension include:
- Development of blood clots which can slow or even block the flow of blood and oxygen to the brain. This can lead to a stroke.
- Increased risk of developing dementia or vascular dementia due to obstructed blood flow to the brain.
- The risk of developing transient ischemic attack (TIA) is often called a ministroke. This is caused by hardened arteries (due to high blood pressure or blood clots).
- A stroke caused by a lack of oxygen and nutrients in the brain. This causes brain cells to die, and damaged blood vessels can leak or rupture.
- Dementia caused by narrowing or blocked arteries (vascular dementia).
- Mild cognitive impairment caused by high blood pressure.
Neither recreational marijuana nor medical cannabis is recommended for any individual with a history of cardiovascular problems or hypertension. When you attend your doctor’s appointment to apply for a medical marijuana card, your health history will be reviewed to help reduce risks.
Does Lower Blood Pressure Affect Brain Functioning?
With so much education about hypertension (high blood pressure), you may think that low blood pressure is good. But hypotension can present other health risks that many people are unaware of.
Indica cannabis strains often create symptoms of relaxation and drowsiness. Signs inside your brain and the endocannabinoid system are sent to essentially “slow things down.” One of the side effects of the neurotransmitter messages is reduced heart rate and blood pressure.
When the human brain experiences loss of blood pressure, the following symptoms and health risks may occur:
- Low blood pressure contributes to impaired cognitive performance. This happens when the brain receives a lower volume of blood, oxygen, and nutrients.
- Patients may be prone to escalated feelings of depression or anxiety.
- Increased headaches.
- Dizziness and fainting.
- Increased risk of deep vein thrombosis.
- Damage to the heart and overall cardiovascular system.
Your method or route can increase or decrease coronary artery risk development. Chronic cannabis users that use smokable types of marijuana may be at a higher risk for impairment. Also, consuming nicotine with cannabis can increase possible side effects and problems with high blood pressure and hypotension (low blood pressure).
Changes in Mood After Taking Cannabis
Some strains of cannabis can make you feel like you go from 0-60 in less than five minutes in terms of your mood. If you are experiencing anxiety, some strains can help push the pause button and provide relief. Other strains can make you feel energetic and happy and put a big smile on your face.
The mood-altering psychoactive effects of marijuana use are well known. But how does that change in mood occur in the brain? And what are the chemical processes going on that flip the switch to provide relief from low mood?
Cannabis can change the way you think, feel, and act. Some of those changes might be welcome, for example, if you struggle with clinical depression. But regular marijuana use can create changes in your mental health that can persist after you have stopped using cannabis, according to some studies.
Long-term marijuana use can, in some cases, result in a clinical condition called amotivation syndrome. The symptoms of this disorder remove the desire to engage in activities or experiences you previously enjoyed.
Not all cannabis users will develop low motivation. But some clinical evidence suggests that long-term marijuana use can create changes in the brain that reduce drive and overall motivation.
Memory and Learning Impairments
One of the biggest concerns about marijuana use is its impact on cognition. While some studies suggest that intermittent use of cannabis poses a minimal risk in terms of brain functioning, there are worries that long-term use could lead to cognitive impairment.
After regular marijuana use, cannabis can hurt personal performance. That includes your ability to learn new skills, concentrate or focus on school or work activities. For heavy cannabis users, this could limit their ability to learn new skills and participate in higher-paying employment opportunities.
Some studies have measured that cannabis use disorder (excessive marijuana use) can result in the loss of IQ points; specifically, a recent study in New Zealand reported a reduction of -8 IQ points.
With age, humans naturally lose neurons in the hippocampus region of their brain. The saying “you can’t teach an old dog new tricks” has some merit. The loss of brain neurons makes it more challenging to learn. There are clinical studies that propose the effects of marijuana may accelerate the age-related loss of hippocampal neurons.
While the Hollywood persona of the “average stoner” with below-average motivation, income, and smarts is not true for everyone, there is sufficient evidence to suggest that heavy and long-term marijuana use can have a lasting impact on cognition and intelligence.
What Kind of Neurological Disorders Can Be Caused By Cannabis?
The DSM-5 is the reference for psychological disorders. In the reference, there are seven (7) known neurological problems that long-term cannabis users may face, mainly if they use high-potency cannabis daily.
According to the DSM-5, cannabis-induced neurological disorders include:
- Cannabis Intoxication.
- Cannabis Withdrawal.
- Cannabis Intoxication Delirium.
- Cannabis-induced Psychotic Disorder.
- Cannabis-induced Anxiety Disorder.
- Cannabis-induced Sleep Disorder.
- The Chronic Effects: Cannabis Use Disorder.
While many patients experience relief from mental health conditions like anxiety and depression, using cannabis can have the opposite effect. While no studies link cannabis use directly with the development of neurological disorders, studies have suggested it can worsen pre-existing mental health problems.
Some studies have linked marijuana use to the increased risk of developing psychiatric disorders, including schizophrenia. Researchers do know that cannabis concentrates pose the highest risk. But a genetic predisposition to specific mental health disorders is also a factor.
If you have a genetic vulnerability to schizophrenia, with one or more close family members diagnosed, cannabis use may increase your risk of developing the condition. Specifically, a variant of the AKT1 gene may increase the risk of schizophrenia and psychosis for long-term cannabis users.
Patients diagnosed with schizophrenia are not recommended for medical cannabis, as cannabis can amplify the symptoms. And possibly harm the patient.
How Does Cannabis Impact Sleep and Problems With Insomnia?
When you have insomnia, marijuana use may help you get better sleep. There is no clinical evidence to suggest that the effects of marijuana do anything to fix a disrupted circadian rhythm permanently. Yet. But there may be some benefits.
Some clinical studies have reported that cannabis can alter your sleep architecture or the time your body and brain spend in different sleep stages. The average person spends about 13% to 30% of their time in the deep sleep stage.
The deep sleep stage is the most restorative rest period for your body. During deep sleep, your body releases hormones that repair and build muscles and tissues. A healthy immune system relies on deep sleep as well.
Cannabis also reduces REM sleep. With regular marijuana use, some people may notice that they no longer remember their dreams. That is because THC reduces the time you spend in rapid eye movement (REM) sleep.
There is a downside to less REM sleep, however. The REM phase of the sleep cycle is where the brain processes information, including memories and emotions, recently experienced. This can be a benefit, however, to patients with post-traumatic stress disorder, as it may help reduce the frequency of recurrent nightmares.
Indica-dominant strains may help reduce upsetting thoughts and relieve pain symptoms. And marijuana use of Indica strains can also help relieve pain, so that muscle spasms, neuropathy, and other chronic pain symptoms do not waken the individual.
What Types of Cannabis Intake Methods Are Worse for Your Brain?
Health care professionals are most concerned about cannabis use disorder and marijuana’s long-term effects. Recent marijuana studies hint that two variables can increase memory impairment and other effects on the brain.
The potency of cannabis plays a factor. While cannabis is not socially considered addictive, studies have shown that you can build resistance to cannabis over time. Requiring higher potencies to get the same psychoactive or physiological effects of marijuana.
High-potency cannabis and cannabis concentrates may increase the risks and adverse health effects. The most significant risk is for young adults, but long-term cannabis dependence can cause changes in brain connectivity and emotional regulation.
In 2015 a study from King’s College in London found that smoking a high-potency type of cannabis called “Skunk” impacted the white matter connections between two hemispheres of the human brain. The white matter of the brain is responsible for communicating messages between different areas of the brain, and it can impair cognitive function.
The second factor is the frequency of use. Some patients use medical cannabis only as needed. When other therapeutic methods are not providing relief, people who habitually use cannabis daily may be at a higher risk of irreparable negative changes in brain function.
How Does Semi-Synthetic Cannabis Affect Your Brain?
Some people purchase semi-synthetic cannabis products, such as Delta-8 or Delta-10 THC. Like medical cannabis, Delta-THC products are available in various routes, including edibles, vape carts, moon rocks (smokable), and capsules.
Because hemp-derived products were legalized in 2018 (as long as the THC content is below 0.30%), Delta-THC products are available in any smoke shop. Sometimes, they are sold at convenience stores as well.
Are Delta-8 and Delta-10 Safe to Use?
If the medical community knows very little about the long-term effects of marijuana on brain development or functioning, even less is known about Delta-THC products. They are a very new product and have only been available for five years.
That means we are not really sure about the side effeDelta-THC. And since semi-synthetic cannabinoids are processed with organic solvents such as toluene, heptane, and p-toluenesulfonic acid. Strong acids and sometimes metal residue may be left behind on the products.
Acids and heavy metals can damage molecules in the brain and throughout the body. Exposure to chemicals found in some Delta-THC products can also impair DNA repair and energy metabolism.
The Effects of Fully Synthetic Cannabinoids on the Human Brain
Unlike semi-synthetic Delta-THC products, synthetic marijuana is not derived from the cannabis plant. Synthetic cannabinoids are sometimes called “Fake Weed,” synthetic cannabis, or K2 Spice. And they are a combination of hallucinogenic chemic substances sprayed onto plant material.
Some chemicals used to create synthetic cannabis are highly toxic and carcinogenic. They are also chemicals that can create permanent brain impairment. The European Monitoring Center for Drugs and Drug Addiction (EMCDDA) received reports of 142 synthetic cannabinoid receptor agonists from 2008 to 2014.
Man-made chemicals present in synthetic cannabis may include:
- Brodifacoum (rodent poison).
One reason that doctors are concerned about synthetic weed is that it binds very strongly to CB1 receptors. Even better than THC! And because of this quality, synthetic cannabinoids can be more than one hundred times the potency of organic cannabis. That makes synthetic cannabis toxic and dangerous to human health.
Side-Effects from Synthetic Cannabinoid Use
Synthetic cannabinoids can impact CB1 and CB2 receptors throughout the body but predominantly in the brain. Some of the harmful effects of synthetic marijuana use include:
- Moderate to severe memory loss.
- Seizures and involuntary muscle contractions or spasms.
- Intense paranoia.
- Respiratory problems.
- Cardiovascular risks.
- Violent behavior.
- Impaired kidney functioning.
Harmful physical side effects, permanent brain damage, and even fatalities are caused by synthetic cannabis. It may look like organic cannabis flower, but synthetic cannabinoids are dangerous to consume. And severely toxic to the central nervous system and brain.
Risks Associated with Cannabis Butane Hash Oil (BHO)
Some people prefer to use cannabis concentrates and dabbing as a marijuana use route. But how the concentrate is extracted and processed can make a big difference in harming your health. Butane hash oil (BHO) is manufactured using chemical solvents, with butane gas as the primary chemical extraction chemical.
Exposure to butane can cause direct toxicity to the brain and the myocardium (the middle and thickest muscle layer of the heart wall). Butane makes the myocardium more reactive to the effects of catecholamine. That can contribute to the development of a life-threatening condition called tachyarrhythmias.
Daily Exposure to Brain-Harming Butane Lighters
The use of BHO can cause psychological distress to the brain and symptoms of dizziness and anxiety. The risk of butane toxicity is even higher if concentrated marijuana use involves a butane torch or lighter, which increases exposure every time the individual dabs.
The inhalation of butane is known to cause permanent brain damage through asphyxia. Some clinical studies have suggested that a single exposure to high concentrations of butane may cause irreparable damage to the brain.
For safer marijuana use, consider switching to a hemp wick lighter instead of a butane torch. It may help reduce some of the health risks associated with smokable cannabis.
Adolescent Cannabis Users At Greater Risk of Cognitive Impairment
Children and young adults are most at risk of cognitive impairment from cannabis. That is why in most states, marijuana use is limited to low-THC products and administered by a registered caregiver.
Cannabis can have a catastrophic effect on adolescent brain development. What concerns the medical community in the United States is the rate at which teens and tweens are using cannabis. In 2019, one study reported that 37% of American high school students said lifetime use of marijuana.
Some studies suggest that marijuana users who start young may be at the greatest risk of damage to brain structural abnormalities and future drug abuse. And that is because adolescent brain development continues until age twenty-five (25).
Some of the adverse effects of teen marijuana use include:
- Impaired thinking and problem-solving skills.
- Reduced memory and learning performance.
- Attentional difficulties.
- Increased risk of developing clinical anxiety or depression.
- Problems with coordination and balance.
More longitudinal (long-term) studies of the effects of marijuana on brain development are needed. New studies are underway, but there is not enough data to conclude the causes and consequences of marijuana on brain development. And whether damage to the brain development is permanent.
The current clinical practice guidelines about cannabis for pediatric care exercise caution. Often physicians only recommend medical marijuana use (with caregiver supervision) for children with debilitating health conditions. And for patients who have exhausted all ineffective treatment options.
How Long Does it Take for Your Brain to Recover After Using Marijuana?
Let’s start by discussing how often cannabis users have asked, “how long does THC stay in my system?”. And for obvious reasons, if you have to submit to a drug test for any reason, you want to screen clean. That means showing no traces of THC in your body.
There is also no shortage of products, including shampoos and even beverages advertised to help you purge THC from your system. It would be nice if it were that easy, but THC remains detectable in the body for a long time.
You can test positive for THC after ninety (90) days, as it is present in the hair follicles. In saliva, THC content is detectable for 24 hours and up to twelve (12) hours in blood samples. Urine samples will show THC exposure after 24 hours as well.
How long your body holds on to THC depends on:
- The potency of the cannabis consumed.
- The route of THC consumption (inhalable versus edible).
- The amount consumed.
- The overall frequency of cannabis use.
- The level of hydration (or dehydration) in the body.
- The metabolism of the individual.
- Other health factors, such as weight, genetics, and diagnoses.
When considering what cannabis use could do to the brain structure and impairment in specific brain regions, it is not a matter of how long the THC remains present in cells. The question really is, how long does the brain involved changes last?
Medical science has no definitive answer yet, but studies suggest the negative changes could be permanent. Understanding whether the effects of marijuana on the brain intensify with age is still unknown.
What Happens to Your Brain When You Stop Smoking Weed?
Regular marijuana users know what it feels like in the brain and body after ingesting cannabis. You will either want to curl up on the couch with your dog and turn on Netflix or organize your closet. It depends on the strain, doesn’t it?
What actually happens to your brain after you quit taking THC? The first thing you may experience (which could surprise you) are some withdrawal symptoms. Cannabis withdrawal may disrupt your sleep, make it difficult to focus or concentrate, and you may experience abnormal irritability. You could also endure headaches and vivid dreams for 30-45 days after quitting cannabis use.
Some people may notice changes after they stop smoking weed. Those changes can include:
- More energy and motivation.
- Less emotional behavior or reactivity.
- Improved ability to focus and concentrate.
Studies indicate that after cessation of marijuana use, the brain may begin to heal some neural pathways. And undo some of the negative changes THC causes in the orbitofrontal cortex. No studies currently suggest that cessation of cannabis will undo all molecular changes that occurred in the brain, central nervous system, or tissues, however.
Your body can develop something similar to an extreme allergy to cannabis. The condition is called cannabis hyperemesis. If you develop the condition, your body can react severely to cannabis, including vomiting, cramps, and nausea.
Once your body has developed cannabis hyperemesis, you cannot continue using cannabinoid products. Even being in the same room with smokable cannabis can trigger an uncomfortable reaction.
Once your brain detects cannabinoids (including THC), it can kick the symptoms of nausea into high gear, often within seconds. And the only cure for cannabis hyperemesis is to obtain from cannabis indefinitely.
What Can You Do to Lower Your Risks?
If you are a medical cannabis patient relying on doctor-supervised marijuana to moderate your symptoms, what can you do to lower your risks? Because science doesn’t know what side effects may be temporary or permanent, it’s wise to educate yourself and proceed cautiously.
Researchers speculate that many acute brain impairments and disorders are caused by 1) the potency of cannabis used and 2) the frequency that cannabis is consumed.
It is important to understand that the human body will develop a tolerance to cannabis, requiring higher potency over time. But with a higher potency (and increased frequency of use), patients may be more at risk for cognitive impairment later in life.
Complimentary Use of Cannabidiol (CBD)
Cannabidiol has many properties that can help protect brain health. Switching to cannabis strains that have higher than average CBD content may help. Or taking a daily CBD supplement.
Clinical studies have shown that cannabidiol (CBD) has neuroprotective effects. It interacts with the CB2 receptors and helps reduce inflammation. This can help reduce the severity of damage caused by inflammation and the brain.
Cannabidiol and THC work together (entourage effect) to provide physiological and psychoactive effects. But CBD can tame some aspects of THC, and many patients prefer less intoxication, with more of the wellness benefits that CBD can provide.
Reducing the Risk of Cannabis Use Disorder
The development of cannabis use disorder is a potential risk for any patient who uses cannabis frequently. Cannabis use disorder is a clinical diagnosis that implies an addiction to cannabis. To the extent where the patient is using cannabis to the detriment of their mental or physical health, relationships, and activities of daily living.
Some studies estimate that 3 in 10 Americans have cannabis use disorder. While cravings are not common with cannabis, people who have been heavy users of marijuana can experience uncomfortable withdrawal symptoms. Young adults who start using cannabis before the age twenty-five (25) are more at risk of developing cannabis use disorder.
One strategy is to try to lower the potency and frequency of the medical cannabis that you use. Some people also try abstaining for 1-2 weeks on an intermittent cycle to allow THC levels in the body to drop. This may also help reduce the toxic effects of marijuana on the brain.
Discuss Your Symptoms With a Marijuana Doctor
Marijuana use may help with symptoms; it does for many patients. But cannabis is still a drug that can have side effects. Unlike prescription medications that undergo 10-15 years of clinical trials and development, we don’t have long-term data on regular cannabis use.
It is easier now to conduct clinical studies and gather information about short and long-term cannabis use in the United States. But more research is needed. In the interim, the health community has provided information about possible risk factors that patients should know.
Compassionate doctors at our office can answer any questions or concerns you have. Schedule an appointment with a marijuana doctor to discuss any changes in your symptoms. And explore complimentary therapies (in conjunction with doctor-supervised cannabis) to help you manage your symptoms better.
With over 25 years of specialty training in Internal Medicine, as well as fellowship training in Functional and Sexual medicine, Dr. Maginso added Plant Medicine (Medical Marijuana) to her niche practice as of 2017. She is licensed in the State of Florida and attended the University of the East (UERM) in Quezon City, Philippines as well as the University of Medicine and Dentistry in Newark, NJ.
She joined DocMJ in 2019 to align with a known group of compassionate physicians that empower their patients to be better versions of themselves. Her favorite hashtag is #powerpassionperformance, using the combination of optimized bioidentical hormones, medical marijuana, plasma therapies, and sexual wellness.
She is an author, speaker and community advocate for Medical Marijuana, Sexual Health, and the empowerment of mature women.