A drug raises a measured thinking ability in healthy adults

The pill that makes a healthy person smarter is one of the oldest promises on this tree, and the one with the least behind it. Stimulants make tired people more alert and quicker to react, and students take them for that. But alertness is not reasoning, and when healthy, rested adults are tested on memory or problem solving in properly controlled trials, the gains are small, inconsistent and rarely repeated. The entry is kept strict on purpose: it waits for a lasting gain in a thinking ability, not a shorter reaction time.

What would count

A placebo-controlled trial in healthy, rested adults, registered before it ran, finds that a drug raises a standard measure of reasoning, learning or memory (not alertness, wakefulness or reaction time) by a margin the trial was built to detect, and a second, independent group repeats the result.

Who settles it: Peer-reviewed trial reports with a registry entry; a regulator's approval for use in healthy people if it ever comes

Where it stands

Idea only. Not yet shown to work in any living animal, so there is no record to point at. Longer than 20 years, if ever.

The last reading

Once a week every upgrade is read against the news, against what would count above. Open a line to see what that week held. Every reading of this upgrade is on this week's reading.

• 16 October 2026 Nothing new

  Nothing in the window meets the test. The nearest is a 2026 trial of a Cistanche and Ginkgo supplement in 117 healthy adults reporting better memory after thirty days, registered in a Chinese registry, with no independent replication; the test asks for a drug, a pre-registered trial with a margin it was built to detect, and a second group repeating it.

Notes

Kept at idea only by the test above, not by ignorance of the literature. Reviews of modafinil and methylphenidate in healthy people find reliable effects on alertness and some on attention, with mixed results on memory and little on reasoning, and no pre-registered replication of a lasting gain. Animal studies of memory-enhancing drugs are plentiful, but none tests what the human test asks for, so the ladder's animal rung is not claimed either. Caffeine and the stimulants are in wide use for alertness; that is a different upgrade, which this tree does not list.