US National Institute on Aging Registers NECTAR Trial of Psilocybin Combined with Cognitive Training

US National Institute on Aging Registers NECTAR Trial of Psilocybin Combined with Cognitive Training

On July 23, the US National Institute on Aging registered the phase II NECTAR trial. The study is expected to enroll up to 200 people over 65, including people with early Alzheimer’s disease and cognitively healthy older adults.

In NECTAR, all participants will spend four weeks completing daily tablet-based tasks that exercise memory, attention, and other cognitive functions. Some participants will also receive two 25 mg doses of psilocybin, given two weeks apart. After each dose, they will remain at the clinic for 24 hours. The remaining participants will follow the same cognitive training program without receiving psilocybin.

The researchers will test whether psilocybin changes the effect of daily cognitive training. Neuroplasticity is the brain’s ability to modify connections between nerve cells in response to experience. The daily tasks provide that experience. Because all participants follow the same training program, differences between the groups will show what the two doses of psilocybin add to the effects of training.

This comparison tests the effect of adding psilocybin to cognitive training. It does not compare training with an ordinary daily routine. In a review of 37 studies of digital cognitive training for mild cognitive impairment and dementia, the benefits relative to active control activities remained uncertain. Both groups in NECTAR receive cognitive training, allowing the researchers to assess the additional effect of psilocybin separately.

The primary measure at four weeks is a composite measure of neuroplasticity called NPCS in the registry. The team will also conduct cognitive tests, brain imaging, sleep monitoring, and safety assessments over six weeks. Enrollment is scheduled to begin on October 1, 2026.