by Amanda Oldt
Recent findings suggest that treatment with psilocybin may “reset” brain connectivity in patients with treatment-resistant depression.
“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,’” Robin L. Carhart-Harris, PhD, of Imperial College London, said in a press release. “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.”
To assess psilocybin for treatment-resistant depression, researchers used functional MRI to measure cerebral blood flow (CBF) and blood oxygen-level dependent resting-state functional connectivity before and after psilocybin treatment among 16 patients with treatment-resistant depression.
One week after treatment, all patients exhibited decreased depressive symptoms.
At 5 weeks, 47% of the cohort met criteria for treatment response.
Whole-brain analyses indicated decreases in CBF in the temporal cortex, including the amygdala, following treatment with psilocybin.
Decreased CBF in the amygdala was associated with decreased depressive symptoms.
Posttreatment, resting-state functional connectivity was increased in the default-mode network.
Treatment response at 5 weeks was predicted by increased resting-state functional connectivity in the ventromedial prefrontal cortex-bilateral inferior lateral parietal cortex and decreased resting-state functional connectivity in the parahippocampal prefrontal cortex.
“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,” Carhart-Harris said in the release. “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.”
Carhart-Harris RL, et al. Sci Rep. 2017;doi:10.1038/s41598-017-13282-7.