In 2020, Erwin Krediet and colleagues published a comprehensive review article on psychedelic-assisted therapy for PTSD and related trauma disorders. The article appeared in a psychiatric scientific journal and is among the most cited Dutch-language contributions to this field.
Krediet maps out three groups of substances. MDMA is discussed as the best-researched form, with strong effects in pilot and phase 2 studies. Psilocybin and LSD are placed in an earlier research stage, but with promising mechanisms via neuroplasticity and the loosening of rigid thought patterns. Ketamine receives attention due to its existing clinical application in depression and the first indications that it may also help with PTSD symptoms.
A strong point of the review is the attention paid to what happens within the session. Krediet emphasizes that the substance alone does not do the work. The therapeutic context, the relationship with the facilitator, the preparation, and the subsequent integration are equally decisive for the result. The authors refer to this as “set and setting” — a concept from the early psychedelic research tradition.The review concludes with a sober agenda. More and larger studies are needed, with better blinding, longer follow-up, and clear protocols for screening and integration. For the Dutch situation, Krediet advocates for a regulated research setting with sound ethical frameworks, instead of the current grey area of commercial truffle providers.