Long-term Effects of Cannabis on The Brain – Are They Positive or Negative?

Governments and associations worldwide are modifying their views on cannabis use. Trials of medicinal marijuana are legal in many countries. And many parliaments are currently discussing legislation to propose a government regulator of the drug. Marijuana is still the product of preference for many illicit drug consumers in many parts of the world. But debate continues about the long-term effects of cannabis on the braincognition, and mental health

Most cannabis users lay their hands on the drug when they are teenagers. There is a general perception that this can confuse critical developmental methods to leave a permanent negative influence on the brain.

Let’s look at what the most advanced research has to tell about the long-term advantages and damages, whether the harms can be undone, and the prospect of making the plant’s sustainable medical use.

Many factors can affect mental health, cognition, and brain structure. It includes age, use of other substances, family bloodline, exercise, education, childhood abuse, pre-existing neurological abnormalities, and the chemical formation of marijuana.

The Plant Profile of Cannabis


Cannabis contains an extensive assortment of cannabinoids. The most famous ones are Δ9-Tetrahydrocannabinol (THC) and Cannabidiol (CBD).

There has been a definite increase in THC levels relative to CBD in marijuana in recent decades. It could be because of numerous circumstances such as differences in the plant growing process, utilizing the different plant species, or consumption method.

THC is liable for the “high” incorporated with weed and produces psychotic symptoms and cognitive impairments. Moreover, scientists believe that CBD can limit the adverse impact of THC on the brain. However, we don’t know what proportion of CBD that is necessary to decrease these adverse effects.

Apart from that, we still don’t know whether the harm from marijuana use can be undone or not. As has happened in Colorado, the formulation of a well-regulated cannabis market may provide researchers access to reliable knowledge about the plant’s chemical structure that an individual is utilizing.

It will make it feasible to directly examine whether CBD has a part to play in limiting the harm or even aiding improvement from the cannabis-related damage to the brain from heavy usage.

Establishing the long-term influence of cannabis on the brain is a study priority for neuroscientists. Solutions are necessary for mostly untouched issues such as whether we could invert any potential harm (through exercise or other substances) and whether increasing CBD level can narrow the adverse impact of high THC cannabis.

Cannabis effects on the developing brain

cb1 and cb2 receptors working

Studies have revealed that individuals who undertake regular and heavy cannabis in their teenage times have a weaker educational accomplishment and IQ, earn lower wages, and are more inclined to engage in heavy drinks or drug usage. Moreover, they also seem to suffer from mental health problems or end up in prison.

Heavy cannabis use – defined as everyday use for at least one year – is consistently connected with more decreased attention and memory and beginning and extended flows of mental health problems, particularly psychotic symptoms.

Researchers have also recognized differences in the brain associated with these cognitive and mental health problems. It’s tough to determine whether marijuana use or other factors created the problems.

It’s often not possible to consider all these circumstances when undertaking cannabis experimentation. So it’s challenging to tell how much of the variation in a participants’ performance on a cognitive assignment, mental health, and brain composition. It is attributable to their level of usage and so many other factors.

Can we reverse the damage caused by cannabis?

We are only springing to understand how well-equipped the human brain is for adjusting to environmental demands. This capacity, known as brain plasticity, indicates that our brain is continuously striving to optimize its functioning.

For instance, a stroke can injure distinct brain sections, but some functioning of that part may probably be repaired as neural links rewire to neutralize the damage.

Similar healing mechanisms may work in cases for the damaged brain from long-term and heavy cannabis use. However, just a few researchers have studied this instance in the context of cognition.

Apart from that, one study discovered that heavy marijuana usage links with memory loss. Still, some people had shown enhancements in their memory once they quit using weed.

Other studies have revealed that as little as three to six weeks of abstinence was enough for memory enhancements. Yet another study observed no cognitive lacks in former users after only three months of sobriety.

Moreover, the psychoactive substance THC is liable for the ‘high’ incorporated with the drug. Heavy marijuana use can also interrupt neural functioning in memory. But again, a six-week period of sobriety was enough to show some improvement at the neural level.

Nevertheless, another study that followed marijuana users over nearly four decades discovered boundaries to the brain’s capacity to improve in those who start using during the adolescent stage. Cognition increased in long-term users after 12 months of avoidance. However, cognitive impairments continued, especially in those who started using the drug early.

Exercise is essential in promoting brain health, including the extension and development of neurons. Inverting cannabis-related harm through avoidance could likely be enlarged with interruptions such as exercise.

The Long-term chronic and acute effects of cannabis

One study in the journal Addiction states the vast analysis of cannabis after years of study, showing its unfavorable effects, both chronic and acute. Researchers have been analyzing the effects of this plant for decades. 

Nevertheless, science has revealed just in the last 20 years, as in part to more meticulous study techniques, and driven by the budding interest in legalization. The new research states what cannabis does and does not perform in the brain, both in the short- and long-term. 

Cannabis has many adverse effects on certain people over the years of use. Nevertheless, the policies of science are not precise. But the researchers imply that widening legalization should increase public awareness of the effects of chronic usage of the drug.

Acute effects of cannabis

The acute effects aren’t so adverse: No one has ever died from a cannabis overdose. However, it is not correct for synthetic marijuana, which can be very nasty. Besides, driving while high increases the uncertainty of accidents, which intensifies if there is also liquor in the system. 

Marijuana usage during pregnancy by a mother could prompt to low birth weight of a newborn child. Otherwise, acute effects primarily include anxietycognitive impairmentparanoiadysphoria, and psychotic symptoms. Generally, new users tend to experience some of these effects.

These particular side effects appear to have climbed over the last two decades. It is because of the reason that the THC content in cannabis has also increased over the years.

Chronic effects of cannabis

Over the long course, things get a little more severe for cannabis users. It’s essential to note that it can be challenging to consider whether causes and effects are actually at the table or something else is going on!

Apart from that, the authors have gone to exceptional measures to separate causation from the association, combing the knowledge for studies that show strongly to effects and causes. 

Have a glance at some of the chronic effects of the long-term use of cannabis.

#1 – Adverse Cognitive Effects

In particular, cannabis relates to diminished learning, memory, and awareness. It hasn’t been precise whether these impacts continue after a person quits using weed, but there’s some evidence suggesting otherwise.

One study found a loss in IQ of 8 points in heavy users, the most considerable drop in people who’d started exercising as teens and resumed daily into adulthood. Somebody who started using the drug in adulthood and ultimately stopped utilizing didn’t mark a decrease in IQ after a year.

#2 – Loss of IQ

Research in New Zealand observed that constant cannabis use in adolescence is responsible for losing approximately 6 to 8 IQ points measured in mid-adulthood.

Significantly, in that study, the individuals who used marijuana vigorously as teenagers and quit using as adults didn’t recoup the lost IQ. points. Users who just started using marijuana intensely in adulthood didn’t lose IQ. 

These results propose that marijuana has its most definite long-term sway on young users whose brains are still bustling and building new connections and maturing in other manners. However, ongoing results from two prospective longitudinal twin studies didn’t support a causal relationship between marijuana use and IQ loss. 

Marijuana users showed a significant decline in verbal ability and general information between the adolescent years (ages 9 to 12) and late adulthood (ages 17 to 20). However, we should note that these studies were shorter in duration than the New Zealand study and didn’t explore the effect of the dose of marijuana. 

#3 – Altered Brain Connectivity

Imaging studies of marijuana’s effect on brain structure in people have shown conflicting results. Some investigations propose that regular marijuana use in youth renders altered connectivity and diminished volume of specific brain districts involved in an expansive executive function. 

These functions include memory, learning, and impulse control. Other studies have not discovered significant fundamental differences between the brains of users and non-users. 

#4 – Change in Brain Structure and Function

There’s been an ongoing discussion about whether marijuana changes the brain, but late proof has recommended that it influence the hippocampus, amygdala, and prefrontal cortex. 

However, it’s hazy how long these effects last, whether they’re related to behavioral changes, and whether they reverse after a person stops using cannabis. 

#5 – Increased Risk of Psychotic Symptoms

That marijuana could increase insane symptoms (dreams, hallucinations, disordered thinking) is moderately lucid. But again, it’s been a chicken-and-egg dilemma, since it’s challenging to show whether causation is having an effect on everything, and what direction the connection goes. 

However, the relationship likely goes the two different ways: Marijuana may prompt crazy symptoms, and early maniacal symptoms may increase the probability that a person will smoke marijuana (mainly if there’s a family ancestry of paranoid disorders). 

#6 – Functional Impairment

Several studies, including two broad longitudinal studies, propose that marijuana use can cause functional impairment in cognitive abilities but that the degree and duration of the impairment rely upon the age when an individual started using, how much they used, and how long they used. 

Among almost 4,000 young adults in the Coronary Artery Risk Development in Young Adults (CARDIA) study followed more than 25 years until mid-adulthood. Total lifetime admittance to marijuana was associated with lower test scores of verbal memory. 

Furthermore, it didn’t influence other cognitive abilities like processing pace or executive function. The impact was sizeable and significant even after eliminating current weed users and changing for confounding factors like segment factors, other drug and alcohol use, and other mental conditions like gloom. 

#7 – Lower Educational Attainment

At the point when pot-smoking begins in adolescence, individuals will, in general, go less far in school – but again, a causal relationship isn’t available among marijuana and the inclination to study. 

#8 – The Risk of Schizophrenia

The study found that cannabis could double the danger of schizophrenia later on. Numerous past studies have recommended this connection, but, as continually, showing causality is hard. The new study cites several well-executed studies that recommend a causal relationship between marijuana and schizophrenia. 

Marijuana use may double the danger of schizophrenia from 7 in 1000 non-users to 14 in 1000 users. On the other side, they point out that users who quit using the drug after a first insane episode have less crazy symptoms and better social functioning moving forward, contrasted with individuals who have a maniacal episode but continue using. 

#9 – Marijuana Exposure During Development

Significant proof from creature research and a growing number of studies in people indicate that marijuana introduction during advancement can cause long-term or perhaps permanent unfavorable changes in the brain. Rats presented to THC before birth, soon after birth, or during adolescence, notable problems with specific learning and memory tasks further down the road. 

Cognitive impairments in adult rats presented to THC during adolescence are associated with auxiliary and functional hippocampus changes. Studies in rats also show that adolescent presentation to THC is associated with a changed prize system, increasing the probability that a creature will self-administer other drugs (e.g., heroin) whenever given an opportunity. 

#10 – Addiction

But just for some individuals. About 10% of all users create dependence syndrome, and in adolescence, the number is 1 in 6. Withdrawal syndrome is also a genuine marvel, with gloom, anxiety, insomnia, and appetite unsettling influence being the main symptoms, which can often be sufficiently severe to influence everyday life. 

#11 – Gateway Drug

Regular teenage marijuana users are more prone to use other drugs later on – but again, scientists don’t understand whether the link is causal. 

Effects of Cannabis on Memory and Hippocampus

Cannabinoid receptors’ distribution in the mouse brain uncovers high degrees of cannabinoid receptors in numerous areas, including the cortex, hippocampus, cerebellum, and core accumbens (ventral striatum). Memory impairment from marijuana use happens because THC adjusts information processing in the hippocampus, a brain zone liable for memory formation. 

A large portion of the proof supporting this assertion originates from creature studies. For instance, rats presented to THC in utero, soon after birth, or during adolescence, show notable problems with specific learning/memory tasks further down the road. Moreover, cognitive impairment in grown-up rats is related to necessary and functional changes in the hippocampus from THC presentation during adolescence. 

As individuals age, they lose neurons in the hippocampus, which decreases their ability to learn new information. Chronic THC introduction may hasten age-related loss of hippocampal neurons. In one study, rats presented to THC every day for eight months (approximately 30 percent of their life-range) showed a degree of nerve cell loss (at 11 to a year of age) that rose to unexposed creatures twice their age. 

Cannabis Effects on Memory Function

Examining the impacts of cannabis on memory function seems challenging. While early observational investigations planned to clarify the longer-term effects of cannabis use on people’s memory function, findings remained dubious. 

Studies for possible confounding factors investigated the acute effects of delta-9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD). These components are the main ingredients in the extract of the cannabis plant in pharmacological challenge experiments. 

Moderately consistent findings are available regarding the emotional impairments induced by a single dose of Δ9-THC on verbal and working memory. It is hazy whether they may persist past the intoxication state. In the long-term, these impairments appear to manifest probably. 

Future experimental and epidemiological studies that consider individual differences, especially past cannabis history and segment attributes and the exact mixture of the ingredients of the consumed cannabis, are essential to clarify the magnitude and systems by which cannabis-induced memory impairments happen. It’s also essential to explain underlying neurobiological instruments.

Positive Long-Term Effects of Consuming Cannabis

We often forget to refer to the positives for all the discussion surrounding the negatives of long-term medical marijuana use. Since researchers’ couldn’t perform a lot of research, we cannot state for sure the long-term positives and negatives of marijuana consumption. 

We can connect the dots and analyze some ideas about how and why cannabis may prove to be positive in the long-term. Here are three different ways cannabis could be beneficial for you in the long-term. 

#1 – Pain Management

As an effective painkiller, the potential of marijuana has created skepticism in the medical society by forcing researchers to reevaluate how we manage pain. These days, individuals often use narcotics to treat post-medical procedure pain. 

Since stress is a significant contributing factor to pain, doctors often endorse antidepressants to patients as well. But rather than combine antidepressants and narcotics, would we be able to instead combine antidepressants with cannabis as a safer, less addictive other option? 

Cannabis may be a satisfactory substitute for antidepressants, but would we make most pain-relieving drugs from cannabinoids rather than other chemicals? Is the eventual fate of pain management in cannabis-based drugs (for example, cannabinoids and terpenes), meditation, and nutrition, with narcotics in just the most essential or extraordinary conditions? Some researchers assume so. 

Anything that helps doctors keep patients healthy, glad, and free from addiction is a win for the medical community. But right now, pain management will be based on authoritative rather than all-encompassing models. 

While that strategy may work for some sufferers, those undergoing long-term pain would almost certainly like to keep a distance from the danger of addiction and other detriments associated with narcotic based pain management. And there might be a superior option for them as a growing body of proof proposes that cannabis can decrease or eliminate the requirement for dangerous drugs like heroin or cocaine. 

#2 – Regrowing Brain Cells

For some years, individuals have felt that cannabis has been killing brain cells. According to one research by the International Journal of Neuropsychopharmacology, CBD can improve brain growth (neurogenesis). The study found that CBD causes brain cells in the hippocampus to grow – in rats and mice. 

CBD could be useful for mood disorders, such as anxiety and depression, since the hippocampus directs feelings and cognitive function. Late research proposes that CBD could also be an effective neuroprotectant that protects the sensory system from injury caused by amyloid proteins linked with Alzheimer’s disease and dementia. 

Moreover, it protects the system from oxidative stress and Potassium Adenosine Triphosphatase (ATPase) damage connected with stroke. Apart from that, it also protects the brain from neurotoxin damage linked to Parkinson’s disease.

So, how does marijuana regrow brain cells and fill in as a neuroprotectant? The assumption is that cannabis raises the endocannabinoid system (ECS) with cannabinoids, later the body reacts by making more cannabinoid receptors to grab them. 

It could be excellent news not just for those suffering from the neurodegenerative disease but also those trembling the neurological impacts of high-association sports like boxing, football, and numerous other sports carrying a threat of brain injury. CBD could turn into the medicine of choice for recovering athletes because of its anti-inflammatory attributes. 

#3 – Homeostasis

Cannabis could be useful for treating a broad scope of medical conditions because of the endocannabinoid system’s job in homeostasis (the body’s maintenance of a constant internal condition). Researchers like Dr. Ethan Russo have postulated that marijuana can help direct a sensory system that is ‘messed up’ and suffering from an endocannabinoid deficiency

Dr. Russo’s work takes a gander at the therapeutic effects of cannabis on migraine, fibromyalgia, irritable bowel syndrome (IBS), and related disorders. Cannabinoid insufficiencies also identify with eating troubles

Sustaining the body’s homeostasis also keeps the immune system healthy, so it is perhaps the best approach to prevent further sicknesses. Any doctor will reveal to you that it is especially challenging to keep the body healthy when such a large number of drugs out there have symptoms that make homeostasis very difficult to maintain. 

Doctors often go to endorse more pills to check the reactions. But cannabinoids like CBD— which has barely any reactions and, as far as we probably are aware, not too many negative interactions with other drugs (research permitting) — could help deal with the eternal pill-remedy cycle along with the difficulties of managing homeostasis. 

Final Verdict on the Long-term Effects of Cannabis on the Brain

The ability to make definitive determinations about marijuana’s long-term sway on the human brain from past studies isn’t sufficient. It’s because the members used different substances, and there is often limited information about the members’ health or mental functioning before the study. 

Throughout the following decade, the National Institutes of Health is funding a major longitudinal study that will follow a considerable sample of young Americans from late childhood (before the primary use of drugs) to early adulthood. 

The study will use neuroimaging and other propelled tools to clarify decisively how and to what degree marijuana and other substances, alone and in combination, influence adolescent brain advancement. 

As with any medicine, we should regard cannabis as equitably and decently as conceivable, noting not just the negatives but also the positives. The complexity of cannabis as a plant sanctions broad research, especially considering the significant number of conditions it can potentially treat, prevent, or even fix. The main thing stopping researchers are awful laws, corrupt politics, and awful administration. 

The changes to increase the availability of cannabis are outpacing our understanding of cannabis’s effect on the brain. Without addressing these shortfalls, a discussion won’t end about the consequences of cannabis use for medical or recreational purposes.

There’s no safe way to use marijuana. But if you wish to grab the full advantage of it, do it as safely as possible.

Click here to learn more about Cannabis and Inflammation


Content in this article is intended strictly for informational purposes. We do not advertise any product or represent any vendor to treat any medical condition. Moreover, we cannot guarantee that information furnished is error-free. We are not liable for any reader’s actions in the influence of this report. Besides, we do not endorse any user reported information, strain, product, or organization. 


Christopher Andrews
I am Christopher Andrew, the owner of 420 Expert Adviser. I have been in cannabis cultivation for more than ten years, and I'm sharing my experience with you guys using this blog!

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