A Single Psychedelic Dose Shows Weeks-Long Impact on Learning

A lab mouse investigates a food pellet as a part of a behavioral experiment studying learning and memory.

Researchers at the University of Michigan have reported that one dose of a psychedelic compound improved learning flexibility in mice, with effects lasting for at least two to three weeks!

The study tested 25CN-NBOH, a compound that targets serotonin 2A receptors. After receiving a single injection, mice were trained to follow a sequence to receive a food pellet. After several days, the rules of the task were reversed. Mice that had received the psychedelic adjusted to the new rules more effectively than those given saline.

Their improvements were seen in multiple ways. During the reversal phase, they made more correct moves, completed tasks more efficiently, and earned more rewards. These changes did not appear during the initial learning phase, suggesting that the compound specifically helped with adapting to new rules rather than with general learning.

This type of behavioral flexibility, often called cognitive flexibility, is a key function of the brain's prefrontal cortex. It is frequently reduced in people living with depression, PTSD, and some neurodegenerative conditions. Difficulty with changing habits or adapting to new information is common in these disorders.

Unlike many previous studies that measure short-term psychedelic effects, this study measured performance weeks after the treatment. This timing is important. It shows that the improvement was not tied to the acute effects of the drug but rather to longer-lasting changes in how the brain functions.

The study's results suggest that psychedelics might support brain plasticity in a way that could be useful for therapeutic interventions. For people facing conditions that reduce cognitive flexibility, strengthening this capacity could help with daily decision-making, planning, and adjusting to unexpected situations.

This study adds to a growing body of research showing that psychedelics can influence brain structure and behavior long after the drug has left the body. Rather than focusing only on symptom relief, future treatments might look toward supporting the brain’s capacity to adapt.