In recent years, psilocybin (the psychoactive ingredient in 'magic mushrooms') has gained increasing amounts of media attention following clinical trials demonstrating its ability to treat depression. Now, a new study by Imperial College London has found that, over a six-week period, psilocybin has similar effects on depression to antidepressant escitalopram.
For the study, the researchers enrolled 59 patients suffering from long-standing, moderate-to-severe major depressive disorder. One group of 30 participants were assigned to receive two doses of 25mg of psilocybin three weeks apart alongside six weeks of a daily placebo. Meanwhile, another group of 29 participants received two doses of 1 mg psilocybin three weeks apart alongside six weeks of daily oral escitalopram, a selective serotonin reuptake inhibitor (SSRI).
The researchers assessed how these treatments, conducted over a 6-week period, affected patients' scores for depression on the 16-item Quick Inventory for Depressive Symptomatology-Self Report. The inventory scores patients from 0 to 27, 27 indicating more severe depression and remission characterized by a score lower than 5.
All in all, the trial did not show a significant difference in depression scores between those on psilocybin and those on escitalopram. Those in the psilocybin group had a mean difference in score or -8 compared to -6 for those treated with escitalopram. Although secondary outcomes (reduction in score of over 50%) were generally more common in the psilocybin group, analyses of these outcomes lacked correction for multiple comparisons and thus should not be over-interpreted.
The researchers nevertheless say that these results signal hope for the potential of psilocybin-assisted psychotherapy to treat depression. To understand how the treatment may give maximum benefit to patients, however, and how it differs from more conventional treatments, larger and longer trials are required.