What Are the Long-Term Effects of Cannabis?

Cannabis use (which is also known as marijuana) has become normalised. Many people use it for fun or to relax. Some even use it to help with medical problems and manage chronic pain. But what happens if you use cannabis for a long time?

In this blog, we explore whether there are long-term health effects of using cannabis.

What Are the Long-Term Cognitive Effects of Cannabis?

When we talk about cognitive functions, we’re referring to the things our brains do to help us think, learn, and remember. When people use cannabis, it can quite literally change the way their brains work from a cognitive perspective, which can impact their attention span and also their ability to process and absorb new information.

This means that cannabis can affect how well someone can focus on something, whether it be for work or even just watching a movie, how quickly they can solve problems, and how easily they can recall memories. In other words, chronic and prolonged cannabis use can make everything around them feel and seem a bit slower and fuzzier. So, although cannabis might make someone feel relaxed or less stressed at the time of use, it can also impact their brain’s ability to work at its best.

For some people, these changes might go away as soon as they stop using cannabis. But for others, especially those who started using cannabis at a young age, the changes might be permanent. Researchers are actively studying this to understand more.

Can Long-Term Cannabis Use Affect Mental Health?

The impact of long-term cannabis use on mental health is a topic of significant research and debate, with various studies highlighting the potential risks and consequences. However, the general consensus is that there is a correlation between marijuana users and the development of depression, anxiety and certain psychotic disorders.

Long-term cannabis use has also been linked to an increased risk of psychosis, a mental health condition characterised by a disconnection from reality. Some of the most disturbing psychotic symptoms can include vivid hallucinations and delusions.

Studies have also shown that heavy cannabis users, particularly in the context of adolescent marijuana use, are at a higher risk of developing psychosis later on in life. A comprehensive study by King’s College London revealed that individuals who used high-potency cannabis daily were five times more likely to develop psychosis than non-users, and 24% of all new diagnoses of psychosis had been linked to skunk, which is a type of cannabis.

This risk is even higher for individuals with a family history of mental health disorders, which suggests there may be a genetic predisposition to mental disorders combined with cannabis use. This can significantly increase the likelihood of experiencing a psychotic episode.

Another of the bigger concerns (apart from the risk of developing psychosis) with long-term cannabis use is its association with anxiety and depression.

Frequent cannabis users are more likely to experience heightened levels of anxiety and depression compared to non-users. A study conducted by the University of Bristol found that individuals who used cannabis frequently were more likely to report symptoms of anxiety and depression.

This correlation may be due to the way the cannabis plant interacts with the brain’s endocannabinoid system, which plays a critical role in regulating mood and stress.

How Does Long-Term Cannabis Use Affect Physical Health?

Cannabis can have many effects on our physical health over the long term. The most obvious one is that smoking cannabis will eventually begin to harm the lungs.

The act of smoking itself, irrespective of the substance, introduces harmful toxins and carcinogens into the lungs, leading to these adverse health outcomes. So, people who smoke cannabis for a long time might develop breathing problems, such as chronic bronchitis, which causes coughing and mucus. It also puts you at risk of developing lung cancer.

Cannabis can also affect the heart. Using cannabis can make your heart beat faster and increase the risk of heart problems. Some studies suggest that cannabis might weaken the immune system, making it harder for the body to fight off infections.

There’s also emerging evidence suggesting that cannabis use may have immunosuppressive effects, potentially impacting the body’s ability to fight off infections and diseases. More research is needed in this area in order to determine whether or not this is the case, but the findings so far suggest that there is a strong link.

Is There a Risk of Addiction with Long-Term Cannabis Use?

Yes. There is always a risk of addiction with long-term cannabis use.

Some people may develop a condition called cannabis use disorder. This means they feel a strong need to use cannabis even when it causes problems in their lives. They might try to quit but find it very difficult.

Signs of addiction include:

• Using more cannabis than intended
• A lack of personal hygiene
• Insomnia or sleeping for extended periods
• Experiencing withdrawal symptoms due to drug abuse
• Withdrawing from friends and family
• Feeling unmotivated and a general sense of irritation
• Spending a lot of time using or recovering from cannabis
• Continuing to use cannabis despite negative effects on their health or life

Are There Any Potential Benefits of Long-Term Cannabis Use?

Despite the risks, research suggests that yes, there are. For example, cannabis can help relieve chronic pain, reduce nausea in people who are actively undergoing chemotherapy, and even control seizures in some medical conditions.

The key difference here, however, is that medical cannabis is different from recreational use. Medical cannabis is used under medical supervision to treat specific health issues. Medical marijuana also does not have the ability to get someone ‘high’ because it does not contain THC.

Recreational marijuana is not controlled and can be altered, which is why there are typically varying levels of THC and other substances that can produce psychoactive effects. This lack of regulation can lead to inconsistent potency and purity, which is why it poses such a risk to users.

Advice for Those Using Marijuana for Medical Purposes

Although a prescription for marijuana is rare here in the UK, it can be granted in certain situations. So, if you are currently using medical marijuana, it’s important that you do so responsibly. Here are some tips to reduce the risks:

• Follow your prescription carefully, and do not overuse cannabis.
• Be aware of how cannabis affects you, and don’t drive or operate heavy machinery when under its influence.
• If you have a history of mental health problems, be cautious and talk to a doctor before using medical cannabis.
• Seek help if you’re finding it hard to control your cannabis use.

There are resources available for people who need help with cannabis and marijuana use disorders. If you’re struggling with marijuana use disorder and need help, don’t hesitate to reach out if you need support.

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John Gillen - Author - Last updated: June 14, 2024

John has travelled extensively around the world, culminating in 19 years’ experience looking at different models. He is the European pioneer of NAD+ (Nicotinamide Adenine Dinucleotide) treatment to Europe in 2010; and recently back from the USA bringing state of the art Virtual Reality Relapse Prevention and stress reduction therapy. His passion extends to other metabolic disturbances and neurodegenerative diseases. The journey continues. In recent times, John has travelled to Russia to study and research into a new therapy photobiomudulation or systemic laser therapy working with NAD+ scientists and the very best of the medical professionals in the UK and the USA, together with Nadcell, Bionad Hospitals own select Doctors, nurses, dieticians and therapists. Johns’ passion continues to endeavour to bring to the UK and Europe new developments with NAD+ Therapy in preventive and restorative medicine and Wellness. In 2017 John Gillen was made a visiting Professor at the John Naisbitt university in Belgrade Serbia.