Early in the morning, before Lagos wakes fully, a group of bus conductors gathers in a dusty garage. The air is thick with smoke, not just from the exhaust of buses lining up for their routes but from the rolled “igbo” leaves passing hand to hand.

They chat, laugh, and complain about their wives, but also prepare mentally for the long, challenging day ahead.

Smoking weed here isn’t only about a high; it’s a ritual that helps them feel part of a brotherhood, a signal of toughness and resilience in a city that demands grit.

This scene, repeated in many corners of Nigerian cities, reveals a deeper social phenomenon — marijuana use has become more than a personal choice; it has woven itself into a cultural fabric where belonging and identity are often tied to cannabis consumption.

It has been reported that Nigeria has one of the highest cannabis consumption rates worldwide, with up to 10 million Nigerians being frequent users.

In many informal spaces, its use has evolved beyond pain killing into a kind of rite of passage — a symbol of authenticity, and creative identity. In genres like Afrobeat, hip-hop, and street pop, marijuana is often associated with being “real,” fearless, and unfiltered, traits that are celebrated in lyrics, performances, and public personas.

This normalization has created an environment where the cognitive and mental health risks associated with cannabis use are often minimized or ignored in favor of cultural validation.

Marijuana and the Brain: Finding Balance

Marijuana, derived from the Cannabis sativa plant, has long been a subject of debate within medicine, neuroscience, and public health. With increasing legalization and accessibility, especially for medical purposes, public perception of its safety and benefits has shifted significantly.

While some praise marijuana for its therapeutic properties — including pain relief, nausea reduction, and symptom management in chronic illnesses — a growing body of research highlights the cognitive dangers associated with its use, particularly when use is heavy or begins early in life.

Withdrawal Syndrome and Aggressiveness

According to the American Center For Disease Control, Cannabis use is likely to increase the risk of short-term psychosis and long-term mental health conditions, such as schizophrenia.

Several studies have also found a link between cannabis use and increased risk of violent or aggressive behavior in certain situations—especially in people with mental health issues or those who misuse cannabis regularly.

Cannabis can sometimes cause irritability, lower self-control, and confused thinking, which may raise the risk of aggression.

Studies published in the U.S. NIH National Library of Medicine show that individuals who use cannabis heavily on a daily basis for many years often experience increased aggression when they stop using.

This aggression is strongest between days 3 and 7 after quitting but usually goes back to normal by about 28 days. These changes in aggression happen alongside small mood changes and are clearly linked to cannabis withdrawal.

Cognitive Risks: What the Science Tells Us

A major 2025 study done by professors at the University of Colorado with over 1,000 young adults, found that heavy cannabis users—those who have used it more than 1,000 times—had less brain activity when doing memory tasks.

Brain scans showed less activity in important areas of the brain that interact with THC, the main active ingredient in marijuana.

The negative effects are strongest in people who use marijuana regularly over a long time and those who started using it during their teenage years, when the brain is still developing. Teen users have a higher chance of long-lasting problems like trouble remembering things, making decisions, and even lower IQ scores.

Some other studies, such as one published by Harvard Medical School suggest that by middle age, heavy users may have an IQ that’s about 5.5 points lower on average. There are also physical changes in the brain, like the smaller size of the hippocampus, which is important for memory.

Even short-term use causes problems, such as trouble paying attention, poor coordination, slower reactions, and distorted sense of time. These effects can make driving, learning, and everyday activities harder.

Perceived and Scientific Benefits of Marijuana Use

The term “cannabis” includes all products that come from the Cannabis sativa plant. On the other hand, “marijuana” specifically refers to parts of the Cannabis sativa plant that contain significant amounts of tetrahydrocannabinol (THC).

THC is the chemical responsible for the psychoactive effects of marijuana — meaning it affects a person’s mind and mood.

Despite the cognitive risks, medical marijuana is being professionally prescribed, for its therapeutic benefits. These include relief from chronic pain, management of chemotherapy-induced nausea, improvement of symptoms related to multiple sclerosis (MS), enhanced sleep quality, reduced reliance on opioids, and psychological benefits for conditions like PTSD and depression.

• Chronic Pain Relief: Trials have validated marijuana’s effectiveness in managing various types of chronic pain, making it a useful alternative or adjunct to opioids.
  

• Anti-nausea and Appetite Stimulation: Cannabis has proven effective in reducing nausea and vomiting in patients undergoing chemotherapy and can stimulate appetite in conditions like HIV/AIDS.
  

• Neurological Conditions: In patients with MS, cannabis-derived products have been shown to reduce muscle spasticity. There is also emerging evidence that cannabinoids may offer neuroprotective effects in diseases like Alzheimer’s and Parkinson’s, though more clinical data are needed.

Conclusion

As the Igbo proverb says, "The one who fetches firewood infected with ants invites lizards into his home" — a witty reminder that our actions have consequences and must be guided by caution.

In conclusion, while marijuana can provide medical benefits when used under a doctor’s supervision, its recreational or unsupervised use, especially when started young or used heavily, comes with significant risks to brain health.

Its effects vary depending on how much is used, how often, at what age use begins, and the method of consumption (such as smoking or edibles).

Young people, particularly teenagers and those in early adulthood, are most at risk, as their brains are still developing and more sensitive to harm.

Balance and wisdom are essential. If marijuana is not prescribed by a doctor, it is best to stay away from it — to protect your brain, your memory, and your future.