There are several methods of inducing an altered state of consciousness, the most common being meditation, hypnosis, and psychedelics. Despite the common belief that these practices have similar effects on the mind, a new study has revealed that the three methods have distinct impacts on the brain. 

Study setup and data analysis

To date, no other studies have looked into the different changes in the brain that occur for each form of altered consciousness. Researchers from the University of Zurich’s Psychiatric Hospital addressed this knowledge gap by directly comparing two pharmacological methods (psilocybin and LSD) and two non-pharmacological methods (hypnosis and meditation). For the study, they gathered resting state MRI brain scan data from four separate studies involving the four different methods of altering consciousness. A total of 107 participants were included in the final sample, all from different age groups and genders. 

One of the study’s researchers, Nathalie Rieser, tells Medical Xpress, “We have been investigating the effects of psychedelics on the brain in various studies, given that altered states of consciousness are becoming increasingly relevant in the treatment of psychiatric disorders. Anecdotally, people often report similarities in experiences induced by hypnosis, meditation, or psychedelics. However, our neurobiological understanding of these states is only just evolving.”

The researchers compared the individual methods to a control as the basis for their analysis. To analyze the data, they used a software tool called Conn19c-toolbox. They constructed equations to determine how different brain regions connected with each other. Then, the regions were grouped into networks. The researchers compared the equations between the four methods and their corresponding control conditions, then applied statistical methods to find any significant differences. They also used machine learning to predict different altered states of consciousness based on patterns of brain connectivity. Using machine learning, they were able to classify images of different altered states of consciousness and could distinguish with 85.5% accuracy between most of the methods but not all of them (1).

Results of the study

The study found that the four different methods of altered consciousness have distinct effects on brain connectivity programs. Although some individuals may report having similar experiences while under different altered states of consciousness, the brain activity for each method has several variations that prove otherwise. There were significant differences in the brain connectivity between the psychedelic-treated patients and those who went through hypnosis or meditation. Machine learning could distinguish between hypnosis and meditation effects on brain connectivity. However, they could not determine the differences between psilocybin and LSD effects. 

In terms of brain activity, all of the methods induced unique changes in the MRI patterns (Moujaes et al. 2023). These distinct characteristics of each method can allow scientists to predict individual responses to treatments in future applications. As a result, the methods can be viewed as three distinct treatments that can not substitute each other but instead have unique impacts on the brain as different therapeutic options for various psychiatric disorders. Now that scientists recognize that psychedelics, meditation, and hypnosis are not one-size-fits-all treatments, they can focus individually on each method and their specialized benefits on the brain.

Implications for future research

The results of the study can help scientists better understand how these different methods impact the mind and how they can be used to treat various conditions. By uncovering the specific ways that these methods impact the brain, the researchers hope that the findings of this study can help clinics understand exactly how each process works in treating certain conditions or individual needs.

The researchers of the study plan on applying their new knowledge to future investigations of psychedelic medicines and their distinctive benefits on the brain. This knowledge could potentially contribute to the development of innovative therapeutic approaches for psychiatric conditions.

“We are now simultaneously working on investigating mechanisms of action of psychedelics in healthy controls as well as their clinical application in the treatment of patients with alcohol use disorder and major depressive disorder,” says Reiser. “We are assessing their efficacy and exploring brain, behavioral, and cognitive changes in response to psychedelic-assisted therapy. The current study is informing future investigations on optimizing psychedelic-assisted therapy.”

These ongoing efforts may further influence the field of psychiatric treatment and lead to new methods of improving mental health symptoms in individuals who have not had luck with traditional therapies and medications.

References

  1. Moujaes, Flora F., Nathalie M. Rieser, Christophe Phillips, Nuno M. P. de Matos, Mike Brügger, Patricia Dürler, Lukasz Smigielski, et al. 2023. “Comparing Neural Correlates of Consciousness: From Psychedelics to Hypnosis and Meditation.” Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, July. https://doi.org/10.1016/j.bpsc.2023.07.003.