Experts Warn of Mental Health Risks from Potent Marijuana

There’s a growing concern among experts that strong marijuana could lead to serious mental health problems, specifically schizophrenia and psychosis.

In the United States, the use of cannabis has surged in the last ten years. In 2023, 21.8 percent of those aged 12 and older—roughly 61.8 million people—reported using cannabis, up from 12.6 percent in 2013.

Alongside this increase in use, the concentration of THC—the psychoactive compound that induces a “high”—has also risen significantly. Today’s THC levels typically range from 20 to 30 percent, which is a stark contrast to the 4 percent average noted in 1995 when the DEA confiscated marijuana.

In fact, some vape pens now contain THC levels that soar into the 90s.

A recent investigation led by researchers from Massachusetts and Colorado examined the effects of highly concentrated cannabis products, specifically those with at least 5mg of THC or over 10 percent of the chemical per serving.

The study reviewed data from 99 studies involving 221,097 cannabis users. A considerable portion—about 61 percent—of participants were aged between 18 and 59, with 4 percent consisting of adolescents. The findings revealed that around 70 percent of the studies linked cannabis products with more than 10 percent THC per serving to psychosis or schizophrenia.

These associations with psychosis and schizophrenia emerged quickly, appearing within the first 12 hours of use and persisting for up to two months thereafter.

Interestingly, the researchers did not clarify how the frequency of cannabis consumption might influence the development of mental health issues.

Dr. Jonathan Samet, an epidemiology expert at the Colorado School of Public Health, expressed concern over the findings, suggesting a cautious approach to cannabis use, especially for individuals with existing psychosis.

One particularly alarming incident involved Bryn Spejcher from Thousand Oaks, California, who, while under the influence of cannabis, stabbed her boyfriend 108 times—before also attacking her dog and herself. After the incident, which occurred in May 2018, she was later convicted for the murder of Chad O’Melia.

However, expert testimony during the trial presented a different narrative about Spejcher. According to forensic psychiatrist Dr. Kris Mohandie, she was a “normal” individual without a history of mental illness who had been overwhelmed by extreme cannabis-induced psychosis that night, triggered by weed provided by her boyfriend.

Spejcher maintained she had only smoked marijuana a few times prior and had never truly experienced getting high. She described how the drug caused her to lose touch with reality, producing alarming voices in her head.

As incidents similar to Spejcher’s continue to increase, many researchers are focusing on the negative impacts of high-potency cannabis, particularly regarding mental health.

The studies analyzed in the investigation included both recreational and therapeutic cannabis users. Medicinal marijuana is often prescribed for various conditions like chronic pain, nausea related to chemotherapy, and epilepsy.

Mixed results also emerged concerning the impacts of cannabis on anxiety and depression. In non-therapeutic studies, 53 percent of participants reported worsening anxiety and 41 percent noted increased depression; interestingly, those without prior conditions were most affected.

Conversely, therapeutic studies showed that patients found relief from anxiety and depression in about half of the cases, particularly those dealing with cancer and neurological disorders.

Notably, 75 percent of the analyzed studies indicated that users were at risk of developing a condition called cannabis use disorder. This condition is characterized by a compulsive use of cannabis despite experiencing significant distress or impairment in daily life.

As cannabis usage has risen, so too has the prevalence of cannabis use disorder in the U.S. In 2023, nearly one-third of cannabis users met the criteria for this disorder.

Experts cite factors like decriminalization, legalization of recreational cannabis, and the broader availability of cannabis products in legal markets as contributors to this trend.

Even though cannabis remains illegal at the federal level, it is fully legal in 24 states and Washington D.C. Currently, a majority of Americans reside in areas where recreational marijuana is legal.

A recent study reinforces this growing concern, highlighting that patients hospitalized due to cannabis-related health issues were 14 times more likely to develop schizophrenia within three years.

The risks associated with cannabis use encompass a range of severe psychiatric symptoms, including potential overdose on THC. In findings, those requiring hospitalization for cannabis-induced psychosis had a 241 times greater risk of schizophrenia.

This temporary mental health issue can result in hallucinations and delusions, largely attributed to rising THC levels in cannabis products.

Dr. Nicholas Fabiano from the University of Ottawa underscored that cannabis today is not the same as that from years past.

While schizophrenia isn’t inherently fatal, it can lead to dire situations, given that affected individuals face heightened risks of suicide due to severe depressive symptoms.

Overall, the investigation concluded that about 0.47 percent of cannabis users experience psychosis symptoms, which equates to roughly one in every 200 users. However, around 76 percent of those who endure these symptoms longer than 24 hours often require emergency care, further increasing their chances of developing schizophrenia.

Treatment for schizophrenia generally involves a blend of antipsychotic medications, therapy, and support, with antipsychotic drugs like risperidone aiming to balance brain chemicals and alleviate symptoms like hallucinations.

Therapy options, such as cognitive behavioral therapy (CBT), can assist patients in managing symptoms and improving their daily living.