High Potency Cannabis Linked to High Risk for Health Problems

The cannabis being circulated today is not the same drug that previous generations used in the mid-to-late 1900s. Today’s cannabis is far more potent, addictive, and harmful.

Paramedics taking a marijuana user to the ambulance

One of the aspects of cannabis risk that many might not think about is just how potent cannabis is today. Further, new research data shows that the more potent the cannabis, the more likely people are to experience harm from using it.

Many older Americans (the parents and grandparents of today’s young people) might think their children or grandchildren using cannabis “isn’t all that bad.” They might think this way because the cannabis used when they were young was not extremely intoxicating. However, the cannabis of today is practically a different drug, far more potent, considerably more mind-altering, more likely to be laced with harmful substances, and more likely to cause long-term health problems.

What the Research Shows About the Cannabis of Today

Today’s cannabis is more potent than cannabis used by previous generations. A study conducted by researchers at the Addiction and Mental Health Group at the University of Bath (UK) found a direct connection between high-potency cannabis and people being treated for cannabis addiction. The research draws on the careful analysis of 20 independent studies involving nearly 120,000 people.1

The researchers analyzed medical data and survey information for each participant, noting that the more cannabis each user consumed and the longer they used it, the more likely they were to experience addiction and other behavioral health problems. This finding complements data from the European Monitoring Centre for Drugs and Drug Addiction that show a 76% increase in people entering treatment for cannabis addiction in the past decade.

“Our systematic review found that people who use higher potency cannabis could be at increased risks of addiction as well as psychosis…”

Woman experiencing psychosis from marijuana.

The researchers went so far as to argue that public health guidelines around cannabis should be shifted to reflect the clear increase in cannabis potency. Quoting lead author Kat Petrilli from the University of Bath’s Department of Psychology, “Our systematic review found that people who use higher potency cannabis could be at increased risks of addiction as well as psychosis when compared to people who use cannabis products with lower potencies. These results are important in the context of harm reduction which aims to minimise the negative consequences associated with drug use.” The researchers also noted that there has been little effort, even in places where cannabis is legal, to educate consumers on the relative potency of cannabis and the harmful short and long-term effects of using cannabis.2

In the 1980s, most cannabis had about 4% THC, THC is the active ingredient in cannabis that gives it a mind-altering property. Most cannabis products today contain at least 15% THC, more than three times as potent as cannabis consumed 40 years ago. Further, some cannabis products can contain THC levels between 50% and 90%, depending on the product.[3]

The Short and Long-Term Effects of Using Cannabis

The more potent the cannabis, the more likely users will experience harmful health outcomes and unwanted side effects. Approximately one in ten cannabis users will become addicted, while one in six users who consume cannabis as a teenager or young adult will become hooked on the drug.

Some of the short-term effects of using cannabis include:

  • Mood changes
  • Altered sense of time
  • Impaired body movement
  • Impaired short and long-term memory
  • Difficulty with problem-solving and thinking
  • Hallucinations, delusions, and psychosis

The long-term effects of cannabis use are extremely unpredictable, which makes them more dangerous. One study reported that people who use cannabis for long periods experience an IQ reduction of about eight points, with no clear certainty that the lost IQ will return after users cease cannabis use.3

People who use cannabis for long periods also experience breathing problems, increased heart rate, intense nausea, and vomiting. Marijuana can increase one’s risk for heart attack and lead to lung infections. Long-term use can even produce health conditions like Cannabinoid Hyperemesis Syndrome, which involves regular cycles of severe nausea, vomiting, and dehydration.4

The Addictive Nature of Cannabis and the Need for Treatment

Helping a young man to get addiction help

Contrary to some beliefs, cannabis is addictive, people can get hooked on it, and when addicted, they’ll need to seek treatment. According to the National Institute on Drug Abuse, at least 17% of Americans who enter drug and alcohol rehab centers claim cannabis is the primary reason they seek help.[^6]

If you know someone who is using cannabis and cannot stop, please help them find and enter a qualified drug rehab center as soon as possible. Cannabis addiction creates real harm in the lives of users, putting them at risk for long-term health crises. Please seek help for your loved one before these effects get worse.


  1. Lancet. “Association of cannabis potency with mental ill health and addiction: a systematic review.” The Lancet, 2022. thelancet.com ↩︎

  2. ScienceDaily. “High-strength cannabis linked to addiction and mental health problems.” Science Daily, 2022. sciencedaily.com ↩︎

  3. PNAS. “Persistent cannabis users show neuropsychological decline from childhood to midlife.” Proceedings of the National Academy of Sciences, 2012. pnas.org ↩︎

  4. NIDA. “Cannabis (Marijuana) DrugFacts.” National Institute on Drug Abuse, 2022. nida.nih.gov ↩︎