The Psychedelic Heart24 December 2021
Scott McGreal :
Recent studies have found that people who have used classic psychedelic drugs, such as LSD, psilocybin, and ayahuasca, often experience beneficial outcomes, including improvements in mental and physical health. Simonsson, Sexton, et al. (2021) reported that lifetime psychedelic use is associated with better self-rated health as well as reduced rates of overweight and obesity. Further studies have found that lifetime psychedelic drug use is associated with other health benefits.
One study found that people who had ever used a psychedelic drug, even once, had lower rates of hypertension (high blood pressure) in the past year (Simonsson, Hendricks, et al., 2021). The study used data from the National Survey on Drug Use and Health, an annual survey that aims to assess the prevalence of substance use and mental health issues in the United States, with data collected from 2005 to 2014.
As well being asked whether they had ever used, even once, a classic psychedelic (specifically, DMT, ayahuasca, LSD, mescaline, peyote or San Pedro, or psilocybin), respondents provided information about many other factors that might be relevant to their health, such as age, sex, race, education, use of other substances, including alcohol and tobacco, income, and so on. Additionally, the authors classified each kind of psychedelic drug into three types based on their chemical structure: tryptamines (including DMT, ayahuasca, and psilocybin), lysergamides (LSD), and phenethylamines (mescaline, peyote and San Pedro). Interestingly, only tryptamine use was significantly associated with reduced hypertension in the past year, with 20% lower odds of having this condition.
In a similar vein, another recent study (Simonsson, Osika, et al., 2021) found that people who had ever used a classic psychedelic reported lower rates of having been diagnosed with heart disease or diabetes in the previous year. This study also used data from the National Survey on Drug Use and Health, from surveys conducted in the years 2005 to 2014, and controlled for the same factors as in the previous study.
When these other factors were accounted for in the statistical analyses, the results showed that people who had ever used any classic psychedelic had 23% lower odds of heart disease in the past year and 12% lower odds of diabetes in the past year. Unlike the study on hypertension though, the type of psychedelic used made no difference to the results-that is, users of LSD, mescaline, and other psychedelics had the same improved health outcomes as those who had used psilocybin, DMT, or ayahuasca.
The authors of these studies note that multiple factors could explain the findings. For example, psychedelic use might induce long-term changes in health behaviour, such as improved diet or reduced smoking. Additionally, improvements in mental health and well-being associated with psychedelic use might reduce stress, which in turn improves general health. Even more intriguingly, the authors go so far as to claim that "classic psychedelics have anti-inflammatory and immunomodulatory properties of importance for both mental and cardiometabolic health" (Simonsson, Osika, et al., 2021), which are supposedly mediated by their effects on the serotonin system.
However, claims about such direct effects of psychedelics on health through the immune system are actually based only on research with animals such as mice and did not even use classic psychedelics. For example, one of the references cited by Simonsson, Osika, et al. (2021) is by Flanagan & Nichols (2018), which reviews studies in mice using the less well known drug 2,5-dimethoxy-4-iodoamphetamine, rather than more "classic" substances such as LSD and psilocybin. Furthermore, it is not known whether using a psychedelic drug infrequently, let alone once, would have any long-term effects on the serotonin system.
Simonsson, Osika, et al. (2021) do acknowledge that the association between lifetime psychedelic use and improved health might not be a case of the one causing the other but might involve a common factor that predisposes people to both use classic psychedelic and to engage in healthy lifestyle behaviors associated with cardiometabolic health. As I noted in a previous post, this could be related to features of a user's personality, particularly openness to experience. Specifically, people who are inclined to use psychedelic drugs tend to be high in openness to experience (Allen & Laborde, 2020), a trait associated with having a complex mental life, such as having an active imagination and a desire to explore new and interesting experiences that stimulate and broaden the mind.
Intriguingly, there is even evidence that psychedelic use may actually increase one's openness to experience in the long-term (Griffiths et al., 2006; MacLean et al., 2011), as discussed in a previous post. Furthermore, a previous study in Germany using a sample of 18,000 respondents found that higher openness to experience was associated with a reduced likelihood of obesity (Bagnjuk et al., 2019). The reasons for this are unclear, although openness to experience might be associated with healthier lifestyle choices, such as being more mindful of what one eats.
The association between lifetime psychedelic use and better health outcomes, such as reduced rates of heart disease, diabetes, hypertension, and obesity, could be related to users being higher in openness to experience. This would need to be tested with further research, and of course, there could be a variety of factors involved.
(Scott McGreal is a psychology researcher with a particular interest in individual differences, especially in personality and intelligence).