Classic psychedelics (LSD, psilocybin, DMT, mescaline) act on the 5-HT2A receptor. SSRIs/SNRIs and antipsychotics interfere with this system — with different consequences depending on the substance.
SSRIs / SNRIs:
- Often a weakened psychedelic effect — which tempts people to redose
- Risk of serotonin-syndrome-like symptoms at higher psychedelic doses or after recently stopping an SSRI
- Delayed complications — depressed moods or sleep problems days later are common
Antipsychotics (risperidone, olanzapine, quetiapine, aripiprazole, etc.):
- Complete blockade of the psychedelic effect possible (depending on the substance)
- Sometimes paradoxical reactions — increased anxiety, dysphoria
- Used clinically to end severe bad trips as an emergency measure (off-label, with caution)
Washout periods:
- SSRIs: 1 week to 6 weeks (fluoxetine), depending on the substance
- Antipsychotics: do it under medical supervision; stopping can carry its own risks
Anyone who has been prescribed antidepressants or antipsychotics by a doctor should avoid using psychedelics without professional support. Clinical studies on psilocybin therapy (e.g. at the Charité) take place in a controlled setting with antidepressants washed out.
We recommend avoiding this combination. Do not pause or stop psychiatric treatment on your own — that carries risks not worth the possible psychedelic experience.