In identical twins discordant for obsessive-compulsive disorder, the affected twin self-administered low doses of psilocybin (1–5 mg every third day) while the unaffected twin did not. The affected twin reported notable reductions in OCD symptoms, improved emotional regulation, and better well-being. However, cognitive flexibility, measured with a set-shift task, remained impaired compared to the unaffected twin. Low-dose psilocybin may alleviate some OCD symptoms but does not fully address underlying cognitive deficits.
In a pair of identical twins where one had obsessive-compulsive disorder and the other did not, the affected twin self-administered low, non-psychedelic doses of psilocybin. After the regimen, the affected twin reported a notable reduction in OCD symptoms, improved emotional regulation, and greater well-being. However, cognitive flexibility deficits—the ability to shift thinking—remained compared to the unaffected twin. This suggests that microdosing psilocybin may help relieve some OCD symptoms but does not fully address underlying cognitive impairments. Larger, longer studies are needed to understand how these low doses work and their potential as a treatment.