“Getting the kind of persistent benefits we’re seeing, which are weeks, months, even more than a year later, would seem to suggest that there’s some kind of cognitive change or changes in the creation of meanings that are happening, said David Yaden, an assistant professor of psychiatry and behavioral sciences at the Johns Hopkins Center for Psychedelic and Consciousness Research.
People involved in psychedelic studies often say that the experience was one of the most significant in their lives, as was the birth of a child or the death of a father. Many say they feel a sense of connection to the universe. “This journey of psilocybin was the most transformative experience of my life,” Mr. wrote. Fernandez in a Medium publication in 2018. “It forced me to reconcile with the mortality of being human. It relieved my anxiety and gave meaning to my life.”
It is this existential catharsis and the personal knowledge that accompanies it that Dr. Yaden and others believe they are so important to healing people. Supporting the theory, several studies have found that the feelings of connection and meaning and mystical-type experiences that people have during their journey correlate with their therapeutic outcomes.
Regardless of which side is right, finding an answer to how psychedelics treat depression brings scientists one step closer to understanding not only how to relieve the symptoms of mental illness, but also potentially how to eliminate them. This is because the truly revolutionary view of both psychedelic therapy and its non-psychedelic chemical cousins is to take medications not daily or weekly, but only once or twice and potentially heal forever. “Wouldn’t it be wonderful if we had a medicine you could take at bedtime and wake up the next day and you’re no longer depressed?” said Dr. Bryan Roth, a professor of pharmacology at the University of North Carolina, Chapel Hill, who is also working to develop non-hallucinatory psychedelic compounds.
Beginning in the 1960s, scientists thought that depression was the result of having low levels of the neurotransmitter serotonin in the brain, and traditional antidepressant drugs, such as selective serotonin reuptake inhibitors, worked by correcting this chemical imbalance. But there were holes in that hypothesis. Mostly, SSRIs increase serotonin levels immediately, but the symptoms of depression usually do not go away until a few weeks after starting the medication.
In the 1990s and early 2000s a new theory emerged that depression, as well as anxiety and PTSD, can result from the loss of synapses in the brain: connections between neurons. Scientists found that people with depression have less volume in brain regions important for mood, executive control, and feelings of reward. Chronic stress and genetics are thought to contribute to the atrophy of neurons and their connections.