One of the most potent and potentially dangerous drugs in circulation today is lysergic acid diethylamide, or LSD for short. Although scientists have carefully documented the pharmacological effects of the drug, specifically its action at specific serotonin receptors, they are still perplexed as to how this action produces the behavioral effects that LSD induces (the “trip”). Essentially, if we were to view the course of LSD usage as a linear road, scientists are aware of the beginning of the road (the pharmacological effects) and the end of the road (the behavioral effects), but the middle is shrouded in mystery.
Before we move on, however, let’s back up for a second and talk about these behavioral effects of this drug. LSD is known to bring about changes in consciousness, including “ego-dissolution,” or a loss in perception of self. Essentially, what this means is that LSD users experience a loss of their identity and enter a state of “complete transcendence” of the self. Moreover, the action of LSD at specific serotonin receptors is also well documented, giving scientists a very good understanding of the initial physiological effects of the drug. The problem is, however, that scientists are puzzled about how this brings about the intense behavioral effects that are associated with the drug.
Recently, a new study provides evidence that LSD interferes with the patterns of activation in the different brain networks that underlie human thought and behavior. But where did these conclusions come from? In the study, Dr. Robin Carhart-Harris and his colleagues at Imperial College London did sequential brain scans of 20 healthy volunteers for over six hours, utilizing two techniques employing both functional magnetic resonance imaging (fMRI), as well as magnetoencephalography (MEG). By using the fMRI, they were able to demonstrate that LSD produced a chaotic brain state that is very similar to that of the prodromal (beginning) phase of psychosis. Specifically, the investigators found out that, when under the influence of LSD, neurons that are supposed to fire simultaneously were no longer synchronized and networks that are normally distinct began to blend together. Moreover, Dr. Carhart-Harris found that LSD produces an increase in blood flow to the visual cortex, which explains the hallucinations. MEG also detected a change in natural brain oscillations, specifically a decrease in alpha waves across the brain. Interestingly, these MEG changes correlated largely with the visual hallucinations, suggesting that under the influence of LSD, users’ visual systems are tethered more to the internal than the external.
Image Source: Rick Madonik
Although LSD has a largely negative connotation associated with it, Dr. Carhart-Harris is confident that with advancing assessment tools, “it may be possible to evaluate potential uses of LSD as a treatment for addiction and other disorders, such as treatment-resistant depression.” Moreover, due to its similarity to psychosis, understanding LSD may also lead to a breakthrough in our understanding of it as well.
Feature Image Source: LSD by Vix Walker
