Psilocybin versus escitalopram for depression shows positive results

Around 30% of people living with depression in the UK are resistant to current treatments, highlighting an urgent need for new therapies. As the researchers of this study highlight, even for patients who have had their depression successfully treated, there is a high risk of relapse, with one in three patients relapsing within the year.

Equally, SSRI treatments often include side effects such as sexual dysfunction, weight gain, fatigue, and emotional blunting.

The authors note that a key consideration of any treatment of major depressive disorder “is its capacity to produce sustained antidepressant response or remission.”

Mounting evidence is increasingly pointing to psilocybin-assisted therapy as an innovative new treatment for the condition, with clinical trials showing that the therapy is capable of producing rapid and long-lasting antidepressant effects.

However, while clinical trials have investigated the treatment itself, they have not compared the treatment to the current gold standard in depression medications or looked at the long-term effects of the treatment.

This Phase 2 trial is the first to compare the long-term antidepressant effects of these two treatments alongside mental health measures including work and social functioning, connectedness, and meaning in life. 

In the trial, patients with major depressive disorder recruited from a UK hospital were administered either two doses of 25mg of psilocybin along with psychological support, or a six-week course of the selective serotonin reuptake inhibitor (SSRI) escitalopram in combination with psychological support.

The findings, published in eClinicalMedicine, revealed that both administered treatments saw sustained improvements in depressive symptoms, however, patients who were administered psilocybin-assisted psychotherapy saw greater lasting improvements. 

These improvements included psychosocial functioning, meaning in life, and psychological connectedness.

Dr James Rucker, Consultant Psychiatrist & Senior Clinical Lecturer in Psychopharmacology, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, said: “The authors have tended to attribute differences observed in this study to comparative differences between the drugs themselves, however, it is also possible that the results reflect biased reporting between groups. 

“This is more likely here because A) studies involving psilocybin tend to attract those with positive preconceptions about psilocybin and negative preconceptions about conventional antidepressants, and B) study participants were unblinded during the long-term follow-up phase that is reported in the paper, so knew which condition they were allocated to.

“This said, the nature of depression varies hugely between individuals, and this calls for the development of a similarly varied suite of treatment paradigms. Psilocybin therapy is certainly a different paradigm of treatment to escitalopram. 

“The observation of similar levels of effectiveness to antidepressants here is encouraging to see alongside the much larger trials of psilocybin currently underway here in the UK, Europe and the US.”

The authors write: “Key limitations of the study include its suboptimal power to detect small but meaningful differences between treatments, missing data, the potential use of additional interventions during the follow-up period, and reliance on self-reported treatment assessments. 

“These factors may affect the interpretation of the study findings and should be considered when evaluating the results.”

With these considerations in mind, the researchers suggest that the findings warrant further investigation into psilocybin-assisted psychotherapy for the treatment of depression.