- A single microdose of 13µg LSD influences brain connectivity, particularly in the amygdala, with observed increases in connectivity with certain brain regions such as the right angular gyrus.
- The mood changes experienced by participants were minimal and varied, although a positive correlation was found between increased connectivity in the amygdala and positive mood changes.
- The study highlights the potential of microdosing as a treatment approach for depression, although further research is needed to explore its efficacy and mechanisms.
Introduction
Bershad and colleagues address the increasing prevalence of depressive disorders and the shortcomings of current antidepressant treatments. They note the rise in anecdotal claims regarding the benefits of microdosing—administering very low doses of LSD, typically between 10 and 15 micrograms every few days. Despite its popularity, this practice has received limited scientific scrutiny, prompting the authors to investigate its potential therapeutic effects.
Mechanism of Action
The researchers explain that LSD functions as a serotonin receptor agonist, particularly interacting with 5-HT-2A/C receptors, with higher doses also influencing dopaminergic systems. However, the specific effects of much lower doses, such as those used in microdosing, remain insufficiently understood. Past research on higher doses has suggested changes in neural connectivity related to sensory processing, indicating that lower doses might have different implications for brain function.
Research Hypothesis
One proposed mechanism for the antidepressant potential of psychedelics involves alterations in the amygdala’s reactivity and connectivity. Previous evidence indicates that higher doses of LSD could lower amygdala reactivity, which may alleviate the negative bias observed in depressive disorders. The current study was designed to further explore how a microdose of LSD affects connectivity and blood flow in the brain, providing insights into any ensuing mood changes.
Study Design and Methods
The authors employed a double-blind, within-subject design involving twenty healthy adults, each participating in two sessions where they received either a placebo or a dose of 13 µg of LSD. Subjective and physiological responses were recorded throughout these sessions, with brain imaging sessions occurring at the expected peak effect of the drug. The focus was on amygdala and thalamus connectivity, particularly regarding how it correlates with variations in mood.
Results Obtained
Among the notable findings, LSD was found to enhance amygdala connectivity with the right angular gyrus and decrease it with other areas like the postcentral gyrus. While the drug did not significantly alter overall mood and cerebral blood flow, an important correlation emerged between increased amygdala–middle frontal gyrus connectivity and heightened feelings of positive mood. Additionally, thalamic connectivity changes were observed, yet these did not correlate with mood fluctuations.
Discussion of Findings
The researchers contextualize their findings within the existing literature on psychedelics and depression. The limited subjective effects of the microdose underscore its potential as a non-invasive therapeutic approach. Enhancements in amygdala connectivity, especially when considering their implications for depression, suggest that microdosing may warrant further investigation in clinical settings. They also recognize the limitations of focusing solely on healthy volunteers and a singular administration of LSD, urging the necessity for future research on repeated dosing and its behavioral impacts.
Conclusion
In closing, this study marks a foundational exploration into the effects of low-dose LSD on brain connectivity among healthy individuals. The observed alterations in amygdala connectivity highlight the importance of further research into microdosing’s potential role in psychiatric therapies, particularly in the treatment of mood disorders.
Read the full paper summary on Blossom.
