Psychedelic Drugs No Risk to Mental Health, Possibly Beneficial

Megan Brooks

August 21, 2013

Using classic psychedelic drugs does not raise the risk for mental health problems; on the contrary, it may offer some protection, new research suggests.

Among 130,152 representative US adults, including 21,967 reported psychedelic drug users, researchers found no significant link between lifetime use of lysergic acid diethylamide (LSD), psilocybin, mescaline, or peyote and an increased rate of mental health problems.

Rather, in several cases, psychedelic drug use was associated with a lower rate of mental health problems, Teri S. Krebs, PhD, and Pål-Ørjan Johansen, PhD, of the Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, report.

The findings were published online August 19 in PLoS One.

Lower Rates of Distress

"We were not particularly surprised. Overall, there is a lack of evidence that psychedelics cause lasting mental health problems," Dr. Krebs told Medscape Medical News.

More than 30 million Americans have used LSD, psilocybin, or mescaline at some time in their lives. Some case reports of mental illness in people who had used psychedelics fueled some concern of a link. But there are "many potential biases of relying on individual anecdotes," Dr. Krebs said. "In particular, mental illness is rather common, and symptoms often appear in the early 20s, which is the same time that people often first use psychedelics."

In the current population study, after adjusting for other risk factors, there was no link between psychedelic drug use and a range of mental health outcomes, including serious psychologic distress, mental health treatment, symptoms of 8 psychiatric disorders (panic disorder, major depressive episode, mania, social phobia, general anxiety disorder, agoraphobia, posttraumatic stress disorder, and nonaffective psychosis), and 7 specific symptoms of nonaffective psychosis.

In fact, lifetime use of psilocybin or mescaline and past-year use of LSD were associated with lower rates of serious psychologic distress. Lifetime use of LSD was also significantly associated with a lower rate of outpatient mental health treatment and psychiatric medicine prescription.

"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 note. Nevertheless, "recent clinical trials have also failed to find any evidence of any lasting harmful effects of psychedelics."

Less Harmful

"This is an important analysis," Matthew W. Johnson, PhD, of the Behavioral Pharmacology Research Unit, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, in Baltimore, Maryland, who was not involved in the study, told Medscape Medical News.

"Although there is evidence suggesting beneficial effects of psychedelics in well-controlled clinical research, that does not address the occurrence of psychiatric adverse effects in the population. It is very interesting to know that these drugs are not associated with adverse mental health outcomes at the population level," Dr. Johnson said.

"However, as the authors note, it is certainly possible that individual recreational users experience harms. This analysis would just suggest that this may be limited in scope, and possibly offset by some individuals also receiving benefit at the population level," he added.

This study "chimes very much with what we know already about psychedelics — that they are essentially much less harmful than other illicit substances," Mark Bolstridge, BSc, MRCPsych, Centre for Neuropsychopharmacology, Imperial College London, United Kingdom, told Medscape Medical News.

"Having personally worked in mental health and trained in psychiatry, I am yet to see any individual suffering from significant mental health problems as a result of using psychedelics. Alcohol, amphetamines, and cannabis, yes, but never psychedelics," said Dr. Bolstridge, who was not involved in the study.

Dr. Krebs noted that "psychedelics interact with a specific type of serotonin receptor in the brain and may stimulate the formation of new connections and patterns. They generally seem to open an individual to an awareness of new perspectives and opportunities for action. People often report deeply personally and spiritually meaningful experiences with psychedelics," she said.

Researchers at Imperial College London have found that healthy adults recall memories much more vividly while under the influence of psilocybin, and functional magnetic resonance imaging (fMRI) data reveal a neurobiological basis for this effect, as reported by Medscape Medical News.

Their research also shows that psilocybin has potential in the treatment of depression, anxiety, and possibly cluster headaches.

Debunking Myths

"We know categorically that psychedelics taken in a controlled clinical environment with appropriate support almost certainly never lead to any recurring or enduring mental health problems," Dr. Bolstridge said.

"All in all, I think the [new] paper is an important addition to the scientific literature, and it can only help in dispelling the myths surrounding these much maligned substances and in reinforcing the case for continued investigations into how these fascinating compounds work in the brain," Dr. Bolstridge said.

"In particular, [it can help in] attempting to determine whether they can prove effective in helping those patients incapacitated by ongoing mental health problems and who are little helped by conventional psychiatric treatments," he added.

Dr. Krebs said clinical trials looking at the potential benefits of psilocybin in alcoholism and smoking cessation are also under way. Last year, she and Dr. Johansen published a meta-analysis of randomized controlled trials of LSD in alcoholism, which provided evidence for a beneficial effect of LSD for treating alcohol dependency.

The study was supported by the Research Council of Norway. The authors, Dr. Johnson, and Dr. Bolstridge report no relevant financial relationships.

PLoS One. Published online August 19, 2013. Full article


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