Effects of the drug last up to five weeks on people who have not responded to other treatments.

Psilocybin — the psychedelic component of magic mushrooms — ‘resets’ the brains of people with severe depression, new research finds.

The small trial found that the positive effects of two doses of psilocybin lasted up to five weeks.

The depressed people who took part in the study had tried all kinds of other treatments, and none had worked.

Dr Robin Carhart-Harris, the study’s first author, said:

“We have shown for the first time clear changes in brain activity in depressed people treated with psilocybin after failing to respond to conventional treatments.

Several of our patients described feeling ‘reset’ after the treatment and often used computer analogies.

For example, one said he felt like his brain had been ‘defragged’ like a computer hard drive, and another said he felt ‘rebooted’.

Psilocybin may be giving these individuals the temporary ‘kick start’ they need to break out of their depressive states and these imaging results do tentatively support a ‘reset’ analogy.

Similar brain effects to these have been seen with electroconvulsive therapy.”

In the study, people were given two doses of psilocybin a week apart.

The first was 10mg and the second 25mg.

Brain scans were used to look at how the blood flow responded to the drug.

After treatment, the results showed reduced activity in the amygdala, a part of the brain important in processing emotions and the stress and fear response.

The researchers found that brain networks are initially disintegrated by the ‘trip’, then reintegrated during the ‘come down’ experience.

People were still reporting reduced depression symptoms up to five weeks later.

Dr Carhart-Harris said:

“Through collecting these imaging data we have been able to provide a window into the after effects of psilocybin treatment in the brains of patients with chronic depression.

Based on what we know from various brain imaging studies with psychedelics, as well as taking heed of what people say about their experiences, it may be that psychedelics do indeed ‘reset’ the brain networks associated with depression, effectively enabling them to be lifted from the depressed state.”

The study’s authors warn people not to self-medicate.

The drug was taken in a therapeutic context with a specialist psychological component.

The study was published in the journal Scientific Reports (Carhart-Harris et al., 2017).