Researchers in France studied 19 young people who misused nitrous oxide (laughing gas) and experienced serious mental health and brain problems. Most were men in their early 20s, and many also used cannabis. The study found that nitrous oxide can damage the brain in multiple ways, causing psychiatric symptoms like delusions and behavioral problems, as well as memory loss and confusion. Brain scans showed abnormal changes in white matter, and blood tests revealed vitamin B12 deficiencies. This research suggests that doctors should consider nitrous oxide abuse when young patients have unexplained psychiatric or cognitive problems.

The Quick Take

  • What they studied: What happens to the brain and mental health when young people misuse nitrous oxide (laughing gas) recreationally
  • Who participated: 19 young people (average age 23) who misused nitrous oxide, mostly men; many also used cannabis
  • Key finding: Nitrous oxide misuse caused serious psychiatric symptoms in 11 people, brain function problems in 2 people, and both types of problems in 6 people. Brain scans showed abnormal changes, and blood tests showed vitamin B12 deficiency in all tested cases.
  • What it means for you: If you or someone you know uses nitrous oxide recreationally, be aware it can cause serious, lasting damage to mental health and brain function. Doctors should consider nitrous oxide abuse when evaluating young patients with unexplained psychiatric or cognitive problems.

The Research Details

This study analyzed 19 cases of serious health problems reported to a French poison control center between 2022 and mid-2024. The researchers reviewed medical records and reports from people who had misused nitrous oxide and experienced psychiatric or brain-related symptoms. They looked at what symptoms people had, what other drugs they used, and the results of medical tests including blood work and brain imaging. This type of study, called a case analysis, helps doctors recognize patterns in how a drug affects people and understand the mechanisms behind the damage.

Case analyses are important for identifying new health risks from drugs, especially when the problems are serious and unusual. By studying multiple cases together, researchers can spot patterns that might not be obvious from individual cases. This helps doctors recognize and treat these problems faster in future patients.

This study has some important limitations to understand. It’s based on reported cases rather than a controlled experiment, so we can’t be completely certain nitrous oxide caused all the problems. The sample size is relatively small (19 cases), and not all participants had complete medical testing. However, the consistency of findings across cases and the clear biological mechanisms make the results meaningful for medical professionals.

What the Results Show

Among the 19 cases studied, psychiatric problems were most common, affecting 17 people total. The most frequent psychiatric symptoms were behavioral disorders (14 people) and delusions or false beliefs (10 people). Brain function problems affected 8 people total, with memory loss being most common (5 people), followed by confusion about time and space (3 people) and slowed thinking (3 people). When doctors tested vitamin B12 levels in 11 people, all had abnormally low levels, with an average of 80.3 μmol/L (normal is above 200). Brain imaging was performed in 8 people, and 6 of them showed abnormal white matter changes that looked like small bright spots on the scans.

Cannabis use was reported in 7 of the 19 cases (38.9%), suggesting a possible interaction between nitrous oxide and cannabis. Vitamin B9 (folate) deficiency was found in 2 cases, and methylmalonic acid (a marker of B12 problems) was elevated in 4 of 6 cases tested. Treatment outcomes showed that 12 people required long-term antipsychotic medications to manage psychiatric symptoms, and 9 people received vitamin supplementation. These findings suggest that nitrous oxide causes multiple types of damage that may require different treatments.

This research adds to growing evidence that recreational nitrous oxide use is more dangerous than previously thought. While nitrous oxide has been used medically for decades with good safety records at controlled doses, recreational misuse involves much higher exposures and frequencies. The psychiatric and cognitive problems documented here are consistent with nitrous oxide’s known effects on the brain’s chemical systems, particularly its interference with vitamin B12 metabolism, which is essential for nerve function.

This study has several important limitations. It’s based on cases reported to one poison control center in France, so it may not represent all people affected by nitrous oxide misuse. Some cases may not have been reported, and the actual number of people experiencing these problems could be higher or lower. Not all participants had complete medical testing, so some vitamin deficiencies or brain changes may have been missed. The study cannot prove that nitrous oxide alone caused the problems, since most participants used other drugs as well. Finally, the small sample size means we should be cautious about generalizing these findings to all nitrous oxide users.

The Bottom Line

Avoid recreational use of nitrous oxide. If you have used nitrous oxide and experience psychiatric symptoms, memory problems, or confusion, seek medical evaluation immediately. Doctors should consider nitrous oxide abuse as a possible cause when evaluating young patients with unexplained psychiatric or cognitive problems. If nitrous oxide use has occurred, vitamin B12 testing and supplementation may be beneficial. (Confidence: High for avoiding use; Moderate for treatment recommendations based on this study alone)

Young adults and adolescents should be aware of these risks, as they represent the primary users of recreational nitrous oxide. Parents, educators, and healthcare providers should understand these dangers. People with existing mental health conditions should be especially cautious. This research is less relevant for people using nitrous oxide under medical supervision in controlled doses.

Psychiatric and cognitive symptoms can develop relatively quickly with heavy nitrous oxide use, sometimes appearing after weeks or months of regular misuse. Recovery may take months to years, depending on the severity of damage and whether vitamin supplementation is started promptly. Some symptoms may persist even with treatment.

Want to Apply This Research?

  • Track frequency of nitrous oxide use (if applicable) and monitor for warning signs: changes in mood or behavior, memory problems, difficulty concentrating, confusion about time/place, or unusual thoughts. Log any psychiatric symptoms and cognitive changes weekly.
  • If you use nitrous oxide, set a goal to reduce or eliminate use. Use the app to track triggers for use and identify alternative coping strategies. If you’ve used nitrous oxide, schedule a doctor’s appointment for vitamin B12 testing and discuss any symptoms you’ve experienced.
  • For people with a history of nitrous oxide use, establish a monthly check-in to monitor mental health and cognitive function. Track mood, memory, concentration, and any psychiatric symptoms. Share this data with your healthcare provider to catch problems early.

This research describes serious health risks associated with recreational nitrous oxide use. If you or someone you know has used nitrous oxide and is experiencing psychiatric symptoms, memory problems, confusion, or other concerning changes, seek immediate medical attention. This information is for educational purposes and should not replace professional medical advice. Always consult with a healthcare provider before making decisions about your health. If you are struggling with substance use, contact a healthcare provider or substance abuse helpline for support.