There is an increasing interest from medical and psychiatric fields in psychedelic drug properties to treat mental and physical illness. Most recently, Simonsson et al (2021) has explored the associations between lifetime classic psychedelic use and cardiometabolic diseases. Heart disease and diabetes are currently leading contributors to the global burden of disease, and a leading cause of death in the Western world. The researchers acknowledged that pharmacological treatment, intensive lifestyle modification or both can delay or reverse the development of cardiometabolic diseases, but noted that no study has so far investigated the long-term cardiometabolic effects of classic psychedelics. If found to be beneficial, they suggest that psychedelics could be used as a possible pharmacological treatment and as part of a programme to facilitate healthy lifestyle changes.
Psychedelics
‘Classic psychedelics’ mainly refer to psychoactive substances known to act as agonists primarily at serotonin 2A receptors, which are often categorised into three classes: tryptamines, lysergamides, and phenethylamines. Most notably, tryptamines include N,N-dimethyltryptamine (DMT), the DMT-containing admixture ayahuasca, and psilocybin. Lysergic acid diethylamide (LSD) comprises the lysergamide class. Phenethylamines include mescaline and the mescaline-containing cacti peyote and San Pedro. Simonsson et al (2021) described the evidence to date, suggesting that classic psychedelics have a good risk profile and can be effective in the treatment of various mental health conditions. However, recent research indicates that classic psychedelics could show a beneficial effect for a range of physical conditions as well, such as heart disease and diabetes.
What is known so far is that there are several ways in which classic psychedelics could influence heart disease and diabetes. For instance, classic psychedelics may facilitate healthy lifestyle changes associated with a beneficial impact on cardiometabolic risk factors such as diet, alcohol and tobacco use, as well as exercise. The byproduct of treating a mental health condition with this type of drug is that cardiometabolic health associated with the mental health condition may improve as the person's mental state improves.
Simonsson et al (2021) report from their review of the literature that classic psychedelics may have anti-inflammatory and immunomodulatory properties of importance for both mental and cardiometabolic health, and that classic psychedelics have a high affinity for serotonin receptor subtypes associated with cardiometabolic diseases (eg serotonin 2A and 2C receptors). This means that classic psychedelics may have direct and indirect effects leading to improved cardiometabolic health. Other factors associated with heart disease and diabetes are obesity and hypertension—these may be lower in those who use classic psychedelics over their lifetime.
The study
Simonsson et al (2021) researched the topic to assess the associations between lifetime classic psychedelic use, heart disease and diabetes. The team predicted that lifetime classic psychedelic use would be linked with lower odds of heart disease and diabetes in the past year.
The research used data from the National Survey on Drug Use and Health, between 2005 and 2014. The focus was any association between the drug and both heart disease and diabetes. Interestingly, the participants who said they had tried a classic psychedelic at least once in their lifetime were observed to have lower odds of heart disease and diabetes in the past year. Classic psychedelic use was observed to have a possible positive effect on cardiometabolic health; however, further research would be required to investigate the potential causal pathways of classic psychedelics on cardiometabolic diseases, as these are still unknown. However, the association itself may lead to a more complex investigation into these pathways, which may benefit drug development targeted at cardiometabolic disease involving novel use of this type of drug.
The results showed that lifetime classic psychedelic use was associated with both lower odds of heart disease in the past year and lower odds of diabetes in the past year, thus providing an indication that further research in greater depth is required to explore the potential link that classic psychedelic use might be beneficial for cardiometabolic health.
However, the researchers did indicate several limitations with their research. The cross-sectional design used in the research limited causal inference, with the regression models controlled for several potential confounders, but the associations possibly being influenced by latent variables that were not included in the dataset could not be controlled for. For example, a common factor that predisposes respondents to classic psychedelic use might also predispose them to salubrious lifestyle behaviors associated with cardiometabolic health. Furthermore, there was no information in the dataset on the context of classic psychedelic use, dose used, or frequency of use, which made the definition of lifetime use unclear in order to link any dosage or variabilities in use to the possible effects. The study was unable to evaluate context, dose, or frequency-specific associations. Additionally, the term ‘heart disease’ covers a wide range of conditions and the term ‘diabetes’ can refer to several metabolic disorders, including type 1 and type 2 diabetes. This means that it is possible that associations may vary across types of heart disease and diabetes.
The study clearly demonstrates the need for further research to investigate potential causal pathways of classic psychedelics on cardiometabolic health. Causal pathways requiring investigation would include lifestyle changes, mental health benefits, anti-inflammatory and immunomodulatory characteristics, and affinity to specific serotonin receptor subtypes. This study is an interesting exploration of the unknown and may prove be the start of a promising treatment method for one of the biggest killers in the world.
Ethical standpoint
It is important to consider ethics when it comes to the attempted use and research of mind-altering drugs that are considered illegal. The Journal of Medical Ethics published an article that acknowledged the recent renaissance in research on psychedelic-assisted psychotherapy has been showing very promising results with regards to the treatment of many psychiatric conditions. McMillan (2020) explored the idea that therapeutic outcomes for patients undergoing psychedelic trials are predicted by the occurrence of a mystical experience—an experience characterised in part by a sense of profound meaning, which has led to hypotheses that psychedelic-assisted psychotherapy is therapeutic because it enhances perception of meaning and, as a result, leads to a meaningful response (a therapeutic mechanism that has been explored throughout philosophical literature regarding the placebo effect). The mechanism of action of psychedelics as meaning enhancers raises ethical questions as to whether it is justifiable to pharmacologically increase the perception of meaning in order to heal patients.
McMillan (2020) uses the hedonistic moral theoretical approaches to argue that if psychedelics operate as meaning enhancers, psychedelic-assisted psychotherapy can be ethically justified. However, an anti-hedonistic objection is given by use of an alternative theory perspective, Robert Nozick's Experience Machine thought experiment, to the case of psychedelic-assisted psychotherapy. McMillan (2020) states that the objection based on Nozick's 1974 paper falls short for two reasons. First, even if pleasure and pain are not the only consequences that have moral value, they are not morally irrelevant. Therefore, therapeutic meaning enhancement can still be justified in cases of extreme suffering. Second, McMillan argues that it is possible that psychedelic states of consciousness do not represent a necessarily false reality, just one that is different to our current perception—it may exist but can only be accessed through psychedelic use, hence the therapeutic meaning enhancement of such drugs is not problematic according to Nozick's standards.
Conclusion
Despite some ethical considerations, in cases of extreme suffering or the consideration that the meaning produced is not necessarily a false reality, the use of such drugs as treatment for mental and physical illness may be a possibly beneficial treatment. This requires further research that explores causal pathways, for example, in the mitigating factors the drug seems to present in lowering risk of cardiometabolic disease. A lot of the factors explored relate to the fact that someone using such treatment would benefit mentally, and therefore may tend to look after themselves better with exercise and a lower intake of alcohol and smoking, thus also benefiting the heart and reducing heart disease and diabetes. It will be interesting to follow developments in this area of research.