Short answer: possibly, but evidence is preliminary. In a small open-label trial of adults with depression and chronic suicidal ideation, a single supervised 25 mg dose of synthetic psilocybin combined with intensive psychotherapy was associated with rapid reductions in suicidal thinking for many participants. An open-label report in The Journal of Clinical Psychiatry describes these findings: see the study.
The dosing occurred in a controlled setting with preparation, about eight hours of monitoring, and integration sessions. Transient side effects like nausea, headache, anxiety, and insomnia were reported, and two participants experienced increased suicidal ideation at some point.
Key limits apply: there was no control group, only 20 participants, specialized therapists were involved, and many resumed antidepressants after week 3. We therefore cannot conclude causality or generalize these results beyond research settings.
This is not a self-treatment option and should only be considered within regulated clinical studies. If there is acute risk or immediate suicidal thoughts, seek urgent professional help.
Hope this helps.