A novel neuroimaging study sheds light on how the psychedelic drug lysergic acid diethylamide (LSD) changes brain function and leads to the phenomenon known as ego dissolution, "one of the most remarkable and least understood domains of the psychedelic experience," experts say.
For the study, 15 healthy adults underwent fMRI after receiving LSD or placebo.
Under the influence of LSD, high-level cortical regions and the thalamus showed increased global connectivity. LSD also increased global integration by inflating the level of communication between normally distinct brain networks. The increase in global connectivity observed with LSD correlated with subjective reports of ego dissolution.
"This hasn't been observed before for LSD. In fact, this is the first LSD neuroimaging experiment in history using sufficiently advanced techniques that allow the investigation of functional connectivity," first author Enzo Tagliazucchi, PhD, of the Royal Netherlands Academy of Arts and Sciences, in Amsterdam, told Medscape Medical News.
The study was published online April 13 in Current Biology.
Implications for Brain Disorders?
"The research implications of our work are that increased communication between areas of the brain involved in introspection (perception of the self) and areas of the brain implicated in sensing the external world underlies the phenomenon of ego dissolution. This is consistent with what this feels like: abolishing the boundaries between yourself and your surroundings, the feeling that you are no longer a separated being from the rest of the universe," Dr Tagliazucchi said.
Clinically, it is too early to say whether LSD-induced ego dissolution can be used to treat disorders such as anxiety or schizophrenia, he said. "However, previous research using psilocybin, another psychedelic whose effects are similar to those of LSD, shows that in terminal-stage cancer patients, ego dissolution can help patients overcome anxiety. Future research should address similar applications of LSD to this and other brain disorders," Dr Tagliazucchi said.
"Generally speaking, psychedelic drugs work in a different way than other drugs used to restore balances in the chemistry of the brain. Psychedelics provide a window of opportunity for the patients to perform new associations and acquire new insights, which can have a lasting effect over time. The hope is that psychedelics can be used a few times during treatment (with professional supervision) and then have a long-lasting benefit on the patients," he explained.
Commenting on the findings for Medscape Medical News, Edythe D. London, PhD, from the Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, who is also a member of the Society for Neuroscience, said the study has yielded new insights.
"For many years, the world has been fascinated by what psychedelic drugs like LSD do, and although there was a detailed knowledge of the action of LSD at specific serotonin receptors, it really wasn't known how those effects at serotonin receptors produce a profound effect on consciousness," she said.
"Changing the connectivity within and between networks within the brain certainly can have a profound effect on consciousness and the sense of ego and how one fits into the universe," Dr London noted.
"Given the fact that LSD and psychedelics and drugs that produce a kind of dissolution of ego can mimic the effects of schizophrenia, understanding the symptomatology and how it's linked to brain function can give us some hints about how to alter those symptoms," Dr London added.
This research was supported by the Safra Foundation and the Beckley Foundation. One author is employed on a part-time basis by GlaxoSmithKline and owns stock in the company.
Curr Biol. Published online April 13, 2016. Full text
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Cite this: The Brain on LSD: Neuroimaging Reveals 'Remarkable' Insights - Medscape - Apr 20, 2016.