It’s no secret that psychedelics produce mind-bending effects and hallucinations. What is far less known is how these drugs can physically alter the brain. Illustrating their findings in a new study published in Cell Reports, scientists at the University of California, Davis believe they now have a better idea, and it could help to treat common mood disorders affecting millions of people around the world.
Researchers tested the effects of psychedelic compounds on neurons grown in a test tube as well as those in the brains of rats and flies. They found the compounds, specifically DOI, DMT, and LSD, caused changes in brain cells (neurons) while increasing the number of connections between them. Ketamine has previously been shown to have this effect, but LSD was found to be even more effective.
The team believe these changes have the potential to fight depression, anxiety, addiction, and post-traumatic stress disorder (PTSD).
Recent studies show that depression, for example, manifests as a “neural circuit disorder”. Throughout the brain, the parts of neurons that project out to connect different regions, called neurites, allow brain cells to talk to each other. When depression strikes, tiny neurites in the prefrontal cortex – our fear response and reward regulator – shrivel up and produce “one of the hallmarks” of depression as well as some cases of addiction, anxiety, and PTSD.
“People have long assumed that psychedelics are capable of altering neuronal structure, but this is the first study that clearly and unambiguously supports that hypothesis,” said senior author David E. Olson in a statement. “What is really exciting is that psychedelics seem to mirror the effects produced by ketamine.”
Psychedelics increased both the growth of these neurites as well as the number of connections between the neurons. Scientists believe this may reverse structural changes that occur as a result of depression.
Because these experiments weren’t conducted in humans, it’s not yet clear exactly what those structural changes might look like in our brains. However, researchers believe the drugs will likely have the same effect. Because they looked at the brains of both vertebrates and invertebrates, they believe the biological mechanism that responds to psychedelics has remained the same across “eons” of evolution.
Olson says his team’s research means a new class of drugs could be created to expand neuroplasticity to create neural growth, but don’t go micro-dosing just yet. Future medications will probably contain compounds of the psychedelics rather than contain the full hallucinatory spectrum.
"If we fully understand the signaling pathways that lead to neural plasticity, we might be able to target critical nodes along those pathways with drugs that are safer than ketamine or psychedelics," said Olson.
It’s part of a growing body of work that suggests psychedelics can be used to treat mood disorders. Previous studies have shown that MDMA is useful in treating PTSD, LSD can permanently reduce anxiety, and Ayahuasca can help treat people with addiction