A landmark clinical trial testing the effect of microdosing LSD on symptoms of attention-deficit hyperactive disorder (ADHD) recently delivered its first data readout and the results have been surprising, to say the least, raising questions over the efficacy of this popular trend.
For about a decade the practice of psychedelic microdosing has flourished in wellness and alternative medicine communities. The idea is a relatively new way to therapeutically consume psychedelics, and can be traced back to the work of American researcher James Fadiman.
While low-doses of psychedelics have been reportedly used by psychonauts for decades, the practice of microdosing as we know it today emerged a little differently. The idea with microdosing is that a person takes a tiny dose of a psychedelic, usually either LSD or psilocybin, with a goal of feeling no acute perceptual effects whatsoever. If you are microdosing properly the effects you feel on the days you dose should be minimal to non-existent.
So why do people microdose?
Over the years the practice has been associated with everything from improved feelings of well-being to bursts of creativity and energy. Some people also believe microdosing helps depression and anxiety, while others have pointed to increased focus or concentration.
Despite this massive wealth of anecdotal evidence, robust clinical research into microdosing has been minimal. The very few placebo-controlled examinations conducted on the practice have pretty consistently struggled to find any effect at all.
The latest clinical trial to test the practice has focused on the effect of microdosing LSD for symptoms of ADHD. The trial is the first to test microdosing in a cohort of patients suffering from a specific condition. Prior trials have mostly focused on mood effects in healthy cohorts or groups with sub-clinical mental health problems. The new trial is also one of the longest and most robust investigations into the popular phenomenon ever conducted.
ADHD was chosen as the target condition as, outside of depression and anxiety, it is the most common disorder often reported as being helped by microdosing. A large 2019 survey found one in three microdosers were using the practice to treat ADHD symptoms.
The trial recruited 53 participants, all fitting the diagnostic criteria for moderate to severe ADHD. Half were given LSD microdoses of 20 micrograms, and the other half were given a placebo. All were administered doses twice a week for six weeks.
At the end of the study period all participants showed statistically significant reductions in their ADHD symptoms, regardless of placebo or LSD. In fact, the placebo group displayed marginally greater symptomatic improvements, although that difference was considered statistically insignificant.
In an email interview study leader Matthias Liechti notes the trial did not explicitly measure expectancy, which is the level of pre-existing belief a person has that microdosing works, but it did track the efficacy of blinding, and interestingly, most participants thought they received LSD, even those in the placebo group. Liechti believes this strengthens the veracity of the trial’s findings.
“This is important as it points to a good blinding!” Liechti tells New Atlas. “There was absolutely no efficacy difference between placebo and LSD. Thus even with a very large study, no effect would have been detected. However, the response was clearly better in those believing they got LSD vs those believing they got placebo (fewer patients).”
Another fascinating aspect of the study was the choice of LSD dose by the researchers. Twenty micrograms of LSD is generally considered to be on the high end of a microdose. In fact, it is a dose high enough that it is likely to be acutely felt by participants.
Liechti suggests the high dose was an intentional choice, driven by the hypothesis that if there were a beneficial effect to be found on ADHD symptoms they would more likely detect it with a higher dose than if the dose was too low. And unsurprisingly, mild psychedelic effects were reported by several participants in the LSD group. However, the big takeaway was that those participants who strongly felt the acute effects of the LSD dose reported similar improvements in ADHD symptoms as those in the placebo group who imagined they had been given a psychedelic dose. So the only real factor that played a role in whether a person’s symptoms improved was whether they thought they were given LSD, regardless of whether they were actually given the drug.
No single trial can offer a definitive answer to whether something works or not, but Liechti is relatively convinced that at least for this condition, with this drug, at this dose, any beneficial effects are likely placebo. He is also keen to stress microdosing may be effective for other types of disorders but proper placebo-controlled trials are the only real way forward for good answers.
“[The] perceived effects of microdosing are mostly a placebo response,” Liechti concludes. “However, there is still limited data on this. This was the first study in patients with a disorder. We cannot exclude, however, that a different schedule (daily dosing) would have been effective. Also microdosing (10 micrograms?) could be effective in treating depressive disorders. This needs to be investigated. Also, single high-dose LSD treatment very likely works in patients with depressive or anxiety disorders. Further research is needed, but randomized controlled trials, not surveys …”
The new study was published in JAMA Psychiatry.