Treatment with LSD and psilocybin at the department of psychiatry at Frederiksberg Hospital in Denmark from 1960 to 1973: an analysis of 324 cases
Nordic Journal of Psychiatry July 10, 2025 Pernille Kølbæk, Søren Dinesen Østergaard, Jens Larsen
Patients treated with LSD or psilocybin at a Danish hospital between 1960 and 1973 who later applied for reparatory compensation received higher doses and more treatment sessions than those who did not apply. Treatment responses were similar between the two groups, but flashbacks were reported by 18.2% of applicants compared to 5.2% of non-applicants. The authors suggest that the high incidence of flashbacks should be considered in future clinical studies of psychedelic treatment for mental disorders.