Meditation has long been linked to lower stress, sharper attention, and better emotional control. A 2025 study, published in Communications Biology, takes that idea much further. Researchers found that people attending an intensive seven-day meditation retreat showed major changes in brain connectivity, blood biology, and self-reported mental experiences. Some of those changes resembled patterns researchers have previously observed after psychedelic experiences.
The findings raise an intriguing question about how far meditation can alter the human brain without drugs. Researchers led by biomedical scientist Hemal Patel at the University of California, San Diego, studied people attending a week-long meditation and health retreat. Their results suggest that concentrated mind-body practices may push the brain toward a more connected and flexible state.
7 Days of Meditation Changed Brain Connectivity
Voit / Pexels / The study included 20 healthy adults randomly selected from more than 500 people attending the seven-day retreat in San Diego. Participants were around 46 years old on average, and their meditation backgrounds varied widely.
Some had practiced meditation for at least six months, while others arrived with no previous meditation experience. That mix gave researchers a chance to examine changes across different experience levels.
The retreat involved much more than sitting quietly for a few minutes each morning. Participants attended lectures about self-healing and the relationship between the mind and physical health. They also completed guided meditation sessions built around conscious breathing and took part in group healing practices. Researchers assessed participants before and after the retreat using functional magnetic resonance imaging, blood plasma testing, and the 30-item Mystical Experience Questionnaire.
The brain scans produced one of the study's most interesting findings. Researchers detected reduced activity within the default mode network and salience network after the retreat. The default mode network plays an important role in self-focused thinking, memories, and internal mental activity. The salience network helps the brain decide which internal sensations and outside events deserve attention.
Those networks did not simply shut down after a week of meditation. Instead, the researchers reported changes consistent with greater communication across normally separated brain systems. Information appeared to move through the brain in a more globally integrated pattern. This broader connectivity is especially interesting because psychedelic research has also linked altered states of consciousness with changes in communication between brain networks.
Blood Tests Pointed to Greater Neuroplasticity
The changes did not stop with brain imaging. Researchers also examined blood plasma collected from participants before and after the retreat. Their analysis found biological signals associated with neuroplasticity, the brain's ability to reorganize connections and adapt to new experiences. Neuroplasticity plays a central role in learning, memory, recovery, and changes in behavior.
The researchers then applied participants' post-retreat plasma to neurons grown in laboratory dishes. Those neurons developed significantly longer neurites, which are extensions that allow nerve cells to build and maintain connections. The finding does not prove that the participants' brains physically grew new neural branches during the retreat. It does suggest that something circulating in their blood after the retreat created conditions that encouraged neuronal growth in the laboratory.
Researchers also detected broader changes in metabolism and immune-related signaling. The blood analysis suggested a shift toward glycolytic metabolism, a process cells use to generate energy from glucose. The team also reported signs of immune modulation. These findings hint that an intensive retreat may affect several biological systems at the same time rather than influencing brain activity in isolation.
'Psychedelic-Like Experiences' Came Without Psychedelic Drugs
Ray / Pexels / Researchers used the Mystical Experience Questionnaire (MEQ-30) to measure experiences involving unity, transcendence, positive mood, and changes in the perception of time or space.
Such experiences almost always appear in clinical research involving psychedelic substances, including psilocybin.
Participants' average scores rose from 2.37 before the retreat to 3.02 afterward. Researchers described that increase as comparable with changes reported in some psychedelic research. The finding does not mean meditation produces exactly the same brain state as psilocybin. It suggests that intensive meditation may reach some overlapping features of altered consciousness through a very different route.
That distinction matters because psychedelics directly affect chemical receptors in the brain, while meditation relies on sustained mental and physical practices. Yet both approaches may influence how normally distinct brain regions communicate.
