People who use LSD and other psychedelic drugs show fewer mental health problems, according to a large population-based study.

Researchers from the Norwegian University of Science and Technology analysed US data from more than 130,000 people, including 22,000 people who’d used psychedelics at least once or more over the past year to establish whether there was a link between the use of psychedelics and mental health problems.

Despite a common perception between drug use and harm, authors Pål-Ørjan Johansen and Teri Krebs said they’d found no link and instead reported in PLOS ONE a “significant association” to fewer mental health issues.

The data came from the 2001-4 National Survey on Drug Use and Health collected in the US, in which participants are asked about mental health treatment and symptoms, including anxiety and mood disorders, psychosis and psychological distress.

Changing perceptions

Psychedelic drugs include LSD, magic mushrooms and the peyote cactus, which contains the active ingredient mescalin. They work by sticking to chemical receptors on nerve cells instead of serotonin, a neurotransmitter that has an influence on emotion and mood. Using psychedelics can change perceptions and lead to altered states of consciousness and hallucinations. Hallucinogens are used by many for recreation, but they’ve also been used through human history in rituals and religious ceremonies.

While evidence suggests that psychedelics are not addictive and don’t cause brain harm, “trips” can induce temporary anxiety that eventually wears off. But despite arguments that LSD and magic mushrooms should be considered as low-risk, they are classified as a Class A drug alongside heroin, cocaine and ecstasy.

While the study found a statistical association with fewer mental health problems, the findings don’t establish whether use of psychedelics directly leads to better mental health. Although other factors, such as gender, use of other illicit drugs and exposure to stressful events were adjusted for, the results point to a pattern, not a cause.

“We cannot exclude the possibility that use of psychedelics might have a negative effect on mental health for some individuals or groups, perhaps counterbalanced at a population level by a positive effect on mental health in others,” the authors said.

Matthew Johnson, a researcher into the active ingredient in magic mushrooms, psilocybin, and its potential to treat addiction and cancer-related distress, said one of the benefits of the study was that it used large data collected by the US government.

“This avoids many of the self-selection concerns that might be present for surveys targeted at hallucinogen users (for example if only those with positive experiences had participated),” he said. “[The data] are very well implemented and captures something very close to a representative sample.”

He added, “One caveat is that as a survey it is not possible to squarely address causality. It may have been that people who were mentally healthier happened to take psychedelics more than the mentally unhealthy.”

“Another, as pointed out by the authors, is that the data don’t demonstrate the lack of harm to some potential individual users. It may be that those cases are infrequent enough to be washed out at the population level, or it may be that some individuals experience mental health benefit and this offsets those with mental health detriment.”

“The analysis adds to the data pointing toward the safety of clinical research and treatment with psychedelics - with appropriate safeguards.”

A research black hole

LSD was first discovered in 1938 and research into the potential medical uses of psychedelics continued into the 1970s, around the time it was banned. But research - and funding - dried up. Since then, LSD and other hallucinogens have become more associated with 1960s political counter-culture as well as negative anecdotes such as people attempting to “fly”. Some experts have called it as a “research black hole”. A clinical trial into LSD in Switzerland in 2008 was the first to be carried out since the 1970s.

There is now an increasing push for more research into the potential benefits of psychedelics in medicine and in mental health. For example, psilocybin could help treat people with severe depression and LSD has been suggested to help people come to terms with a terminal illness. Obsessive Compulsive Disorder and treating alcohol dependence are two other areas where psychedelics could help.

“Everything has some potential for negative effects, but psychedelic use is overall considered to pose a very low risk to the individual and to society,” Johansen said.

“Psychedelics can elicit temporary feelings of anxiety and confusion, but accidents leading to serious injury are extremely rare.”

Charles Grob, Professor of Psychiatry at UCLA and an advocate of psychedelic research, said he believed the research would “help dispel some of the myths that have surrounded our collective understanding of psychedelics since the cultural and political turmoil of the 1960s”.

“Sufficient time has passed to allow for a fresh and objective examination of the true risk and benefit profile of psychedelic drugs.”