Under normal circumstances, most better known psychedelics are relatively safe with no known fatal overdose, long-lasting effects or addiction potential. This counts both for most Psilocin and LSD variants, but there still can be dangerous, even fatal, interactions with other substances.

SSRIs and LSD

In the psychonaut community, it is usually discouraged to take SSRIs (Antidepressants) in combination with LSD or psychedelics in general due to their weakening effect on trips. For example, a generally considered heavy dosage such as 400ug might only feel like 100ug to 150ug. Additionally, Wikipedia mentions more dangerous interactions in combination with tricyclic antidepressants, which is correct and should be treated with extreme caution. Lesser information is found on SSRI interactions with LSD causing Serotonin Syndrome, a very serious and in extreme cases fatal condition usually more frequent with MDMA interactions.

Serotonin Syndrome

Personally, I use Citalopram to manage my depressive states and to overall feel better. It helps me with my everyday life and has nearly no dangerous interactions with drugs, according to my previous research at least. Well, how wrong I was. It was only until a day after my last LSD trip (~400ug), that people mentioned a condition called Serotonin Syndrome to me, after my sitter reported concerning side effects while I was tripping. And even after doing research on this topic in relation to my specific antidepressant and such, I still couldn’t find a lot of information on this interaction. Neither the Wikipedia article for Citalopram nor the article for LSD mention any risk regarding combined use. Reading further into the chemistry of both substances, it makes a little more sense though. Both act on the serotonin system and therefore may cause unwanted effects.

Harm Reduction

If you’re taking SSRIs and psychedelics, you should be relatively safe, if you consider the following:

  • Stopping the intake of your antidepressant within 4 days before the trip should leave the remaining concentration to a minimum, which has little to no risk of causing fatal interactions
  • Make sure to fully understand the substances you are taking. Referring to notable sources might not always be enough in specific cases (such as mine)
  • Have a sitter with you at all times during a trip. If they notice any unwanted side-effects, act immediately. If the side-effects in question are not known to your sitter, look them up. Contact emergency services when in doubt
  • If unsure of an interaction, always start with lower dosages. Especially refrain from taking off-scale dosages (+300ug for LSD) in those scenarios
  • General rule of thumb: Don’t take two substances that might interact with the same group receptors