What Do Different Psychedelics Have in Common? New Research Reveals a Shared Pattern of Brain Connectivity

Psychedelic experiences can involve profound changes in perception, thought patterns, emotions, and a person's sense of self. For decades, scientists have sought to understand what is happening in the brain during these altered states of consciousness.

Modern brain imaging technologies now allow researchers to observe how different regions of the brain communicate with one another while a person is under the influence of a psychedelic substance. These studies have helped researchers develop theories about how psychedelics may temporarily alter information processing throughout the brain.

A major 2026 study published in Nature Human Behaviour represents the largest analysis of psychedelic brain imaging data conducted to date. By combining data from multiple independent studies, researchers investigated whether different psychedelic substances produce similar effects on brain function.

Their findings suggest that despite important differences between substances such as psilocybin, LSD, mescaline, DMT, and ayahuasca, these compounds may share a common pattern of altered brain connectivity.

To understand the study's findings, it helps to first understand what scientists mean by brain connectivity.

The brain consists of billions of neurons that communicate through electrical and chemical signals. Rather than working independently, different brain regions form networks that coordinate specific functions.

Brain connectivity refers to how strongly different areas of the brain communicate or synchronize with one another over time.

Researchers often compare the brain to a large transportation system. Some regions communicate frequently because they perform related tasks, while others usually operate more independently. Brain imaging allows scientists to observe these patterns of communication and how they change under different conditions.

Several major brain networks are relevant to psychedelic research:

The default mode network (DMN) is often active during self-reflection, daydreaming, autobiographical thinking, and internal mental activity. Researchers frequently study this network because many psychedelic experiences involve changes in self-perception and personal identity.

Sensory networks process information coming from the outside world, including vision, hearing, touch, taste, and smell. Changes in sensory processing may contribute to the altered perceptions commonly reported during psychedelic experiences.

Higher-order networks help support complex thinking, decision-making, attention, planning, and integration of information. These networks help people interpret and organize their experiences.

Understanding how these networks interact may provide clues about how psychedelic states emerge.

Individual brain imaging studies often involve relatively small numbers of participants because neuroimaging research is expensive and technically demanding.

To address this limitation, researchers conducted what is known as a mega-analysis. Rather than examining a single study, they combined participant-level data from multiple independent investigations.

The analysis included:

By pooling information across studies, researchers were able to identify patterns that might be difficult to detect in smaller individual datasets.

This approach can increase confidence in findings because results that appear consistently across multiple studies are generally considered more reliable than findings from a single experiment.

The goal was to determine whether different psychedelic substances produce a shared pattern of changes in brain connectivity.

The researchers identified a common pattern of altered connectivity across all psychedelic substances included in the analysis.

The strongest and most consistent finding involved increased communication between higher-order cognitive networks and sensory or motor networks.

Under typical conditions, these networks often operate with a degree of separation. During psychedelic states, however, researchers observed increased interactions between systems involved in complex thinking and systems involved in processing sensory information and movement.

The researchers described this shared pattern as a cross-drug "neural fingerprint."

In other words, despite differences in chemistry, duration, and subjective effects, the various psychedelics appeared to produce a similar overall shift in how information moved through the brain.

Importantly, this pattern was observed across multiple substances and multiple independent research studies.

One of the most misunderstood concepts in psychedelic neuroscience is the idea of increased connectivity.

In simple terms, increased connectivity means that regions of the brain that do not usually communicate as strongly appear to become more synchronized during the psychedelic state.

Researchers observed increased communication between networks involved in:

This does not mean that new physical connections were formed in the brain during the study.

The researchers were measuring temporary changes in communication patterns while participants were experiencing the acute effects of psychedelic substances.

A useful analogy is a city transportation system. Imagine that several neighborhoods that normally interact only occasionally begin exchanging information more frequently during a special event. The roads themselves have not changed, but traffic patterns temporarily look different.

Similarly, the study suggests that psychedelics may temporarily alter how information flows between large-scale brain networks.

These findings align with existing theories proposing that psychedelic states involve a more flexible and interconnected style of information processing.

One reason this study has attracted attention is that it challenges some earlier assumptions about psychedelic brain function.

Several previous studies suggested that psychedelics primarily produce widespread breakdowns or "disintegration" of normal brain networks. According to those interpretations, psychedelics were thought to reduce organization within existing networks.

The new analysis found less evidence for widespread network disintegration than some earlier reports suggested.

Instead, the strongest signal involved increased cross-network communication.

This does not necessarily mean previous studies were wrong. Rather, it suggests that the picture may be more complex than originally understood.

By analyzing a larger dataset across multiple substances, researchers were able to identify patterns that may have been difficult to detect in smaller studies.

The findings support the idea that psychedelic states may involve changes in how information is shared across the brain rather than simply a breakdown of normal organization.

Although brain imaging studies provide valuable information, they cannot fully explain why psychedelic experiences feel the way they do.

Brain connectivity studies measure statistical relationships between patterns of neural activity. They can reveal which regions tend to become more or less synchronized under certain conditions.

However, these findings do not prove exactly how subjective experiences arise.

For example, researchers may observe increased communication between certain networks while participants report changes in perception, emotion, or self-awareness. The two findings may occur together, but brain imaging alone cannot determine whether one directly causes the other.

Many factors likely contribute to psychedelic experiences, including:

As a result, researchers must be cautious when interpreting neuroimaging findings.

The presence of a shared neural fingerprint does not mean scientists have fully explained the mechanisms behind psychedelic consciousness.

Like all scientific studies, this research has limitations.

First, the analysis focused on acute psychedelic effects. The researchers measured brain activity during or shortly after psychedelic administration.

The findings do not demonstrate permanent changes in brain organization.

Second, although this was the largest study of its kind, 267 participants remains relatively small compared to many areas of medical research.

Third, the included studies used different research methods, imaging approaches, participant populations, and dosing protocols. While mega-analyses help increase statistical power, combining studies can also introduce variability.

Fourth, the study focused on functional brain connectivity rather than clinical outcomes. It does not determine whether specific connectivity patterns are beneficial, harmful, or related to therapeutic effects.

Finally, brain imaging provides only one window into psychedelic experiences. Subjective reports, behavioral measures, and long-term follow-up studies remain essential for understanding the broader effects of these substances.

This study highlights the growing maturity of psychedelic neuroscience.

As more research groups share data and collaborate internationally, scientists will be able to investigate larger and more diverse datasets.

Future studies may help answer questions such as:

Large-scale collaborative projects may help researchers move beyond isolated findings and toward a more comprehensive understanding of psychedelic brain function.

This international mega-analysis provides some of the strongest evidence to date that several classic psychedelics share a common pattern of altered brain connectivity. By combining data across multiple studies and substances, researchers identified a reproducible neural fingerprint characterized by increased communication between higher-order cognitive systems and sensory networks.

While the findings do not explain every aspect of psychedelic experience, they offer an important step toward understanding how these substances temporarily influence large-scale brain function. As psychedelic neuroscience continues to evolve, studies like this may help researchers build a more detailed and scientifically grounded picture of how altered states of consciousness emerge in the human brain.

https://www.nature.com/articles/s41591-026-04287-9#Sec13