Magic mushrooms can make colors appear more vivid, alter the sense of time, and send thoughts in unfamiliar directions.
The compound responsible for these effects is called psilocybin, but there’s still a lot we don’t understand about how it works.
Psilocybin is of interest to scientists because of its potential to help treat mental health conditions under controlled conditions.
One question that remains to be solved is whether women and men have different experiences when they take the drug.
Knowing what someone might experience is important for preparing them beforehand and supporting them during a session.
In a new preprint study that has not yet undergone peer review, researchers from Maastricht University in the Netherlands found that women reported feeling some effects more strongly than men, though not all of them.
“What surprised me most was that these differences were selective,” Natasha Mason, who studies how drugs affect the brain and behavior, told ScienceAlert.
Mason and fellow Maastricht researcher Eline Haijen-Bongers led a team that combined results from two trials involving 40 women and 32 men.
All were healthy volunteers with previous experience of drugs that alter perception and thought, known as psychedelics.
The volunteers did not eat mushrooms. They took psilocybin made in a laboratory.
The first trial compared it with another manufactured drug that changes perception and mood, called 2C-B. Participants received both drugs and an inactive substance on separate days.
The second trial examined LSD, another laboratory-made psychedelic. It was also compared with an inactive substance, or placebo.
Neither the volunteers nor the researchers working directly with them knew which substance they were receiving.
Participants rated how they felt throughout the sessions and answered questions about their experiences afterward. Researchers also collected blood samples.
Because some of the volunteers participated in both the trials, the 72 participants contributed 94 active-drug sessions altogether. The team’s analysis took into account that the data in both trials came from the same people.
When the results were compared, women reported feeling more strongly under the influence. They also described greater reductions in alertness and felt less able to control their thinking.
Several differences remained after the researchers accounted for age differences between women and men. The difference in feeling under the influence was most pronounced with psilocybin. Reduced alertness differed significantly with psilocybin and 2C-B, but not with LSD.
Tests of understanding and responding emotionally to other people found no significant sex differences.
One possible explanation was body weight. Each drug was given at a fixed dose regardless of participants’ weight. Because women in the study generally weighed less, the same dose could potentially produce higher drug concentrations in their blood.
But the blood measurements did not show this. Neither peak drug concentrations nor overall exposure during the measured period differed significantly between women and men.
The researchers are therefore considering other possibilities, including hormones. These drugs affect a brain signaling system involving a chemical messenger called serotonin. Hormones such as estrogen can also influence how that system works.
A separate review by members of the same Maastricht team, published in Molecular Psychiatry, explores these possible connections.
“That said, we did not measure hormone levels or account for menstrual cycle phase in this study, so we cannot determine whether hormones contributed to the differences we observed,” Mason explained.
As scientists investigate how psychedelics affect the brain, understanding that people may need different support could help shape future treatments. The findings first need to be tested in larger studies and in patients receiving treatment.
Neither trial was originally designed to investigate sex differences. The sample was small, and the analysis did not adjust for the greater chance of false-positive findings when making multiple comparisons.
“It would certainly be premature to conclude that women need lower doses of psychedelics, or that they respond better or worse to psychedelic therapy,” Mason cautioned.
The study did not investigate long-term therapeutic benefits.
The findings are reported in a preprint paper available at bioRxiv.
This article was fact-checked by Rachel Garner and edited by Peter Dockrill. While we pride ourselves on our process, we are only human. If you spot a mistake, please let us know.
