Women on microdosed LSD made half as many attention lapses in a Maastricht pilot

Both headline figures hold up on a recomputation. In Neuroscience News's account of the ECNP and Maastricht release, a drop of 27 ms from 335 ms is 8.1% ^[14], and 2.4 fewer lapses from 4.7 is a 51% cut ^[15]. They come from one continuous vigilance task, in which volunteers respond rapidly to visual stimuli ^[12].

The denominator is small. The pilot had 24 women in all ^[3], so an even split between LSD and placebo would leave 12 per arm ^[17]. The summary does not give the actual split or a statistical test of the difference between the sexes. Men showing no significant improvement ^[9] is a weaker finding than men and women being shown to differ.

A second explanation is available. On placebo, women began slower and lapsed more often than men ^[11], and a group starting further behind has more room to gain. A pilot this size cannot separate that from a true sex effect. The thing this doesn't tell you is whether men with equally poor baseline attention would respond.

Controlled evaluations of microdosing have returned conflicting evidence on whether the effects are real, driven by expectation, or dependent on who takes the drug ^[13]. Here the volunteers got 15 micrograms, well under the roughly 60 where full psychedelic experiences typically emerge ^[5]. Neither they nor the research staff knew assignments until data collection ended ^[4]. That blinding is the study's control for expectation.

The investigators themselves warn against taking the data to mean that LSD sharpens cognition in all women, or that women are by nature more sensitive to psychedelics ^[1]. We agree with that limit. In our view the pilot supports one narrow statement: in this sample, lapses on one vigilance task fell in women on LSD and did not detectably change in men. Whether sex is the cause or a stand-in for baseline performance needs a larger trial that enrols enough of each sex to test it.