from the things-are-looking-up dept.
An fMRI study has found evidence of a reduction in depressive symptoms after treatment with psilocybin:
A hallucinogen found in magic mushrooms can "reset" the brains of people with untreatable depression, raising hopes of a future treatment, scans suggest.
The small study gave 19 patients a single dose of the psychedelic ingredient psilocybin. Half of patients ceased to be depressed and experienced changes in their brain activity that lasted about five weeks.
However, the team at Imperial College London says people should not self-medicate.
There has been a series of small studies suggesting psilocybin could have a role in depression by acting as a "lubricant for the mind" that allows people to escape a cycle of depressive symptoms. But the precise impact it might be having on brain activity was not known.
Psilocybin for treatment-resistant depression: fMRI-measured brain mechanisms (open, DOI: 10.1038/s41598-017-13282-7) (DX)
Ketamine was significantly more effective than a commonly used sedative in reducing suicidal thoughts in depressed patients, according to researchers at Columbia University Medical Center (CUMC). They also found that ketamine's anti-suicidal effects occurred within hours after its administration.
The findings were published online last week in the American Journal of Psychiatry.
Ketamine for Rapid Reduction of Suicidal Thoughts in Major Depression: A Midazolam-Controlled Randomized Clinical Trial (DOI: 10.1176/appi.ajp.2017.17060647) (DX)
The reduction in SSI score at day 1 was 4.96 points greater for the ketamine group compared with the midazolam group (95% CI=2.33, 7.59; Cohen's d=0.75). The proportion of responders (defined as having a reduction ≥50% in SSI score) at day 1 was 55% for the ketamine group and 30% for the midazolam group (odds ratio=2.85, 95% CI=1.14, 7.15; number needed to treat=4.0). Improvement in the Profile of Mood States depression subscale was greater at day 1 for the ketamine group compared with the midazolam group (estimate=7.65, 95% CI=1.36, 13.94), and this effect mediated 33.6% of ketamine's effect on SSI score. Side effects were short-lived, and clinical improvement was maintained for up to 6 weeks with additional optimized standard pharmacotherapy in an uncontrolled follow-up.
Wikipedia's entry on midazolam notes:
Midazolam, marketed under the trade name Versed, among others, is a medication used for anesthesia, procedural sedation, trouble sleeping, and severe agitation. It works by inducing sleepiness, decreasing anxiety, and causing a loss of ability to create new memories. It is also useful for the treatment of seizures
The researchers used a modified version of Deep Dream to process a panoramic video of the university campus. Then they showed it to 12 volunteers, finding that the visual hallucinations were similar to those brought on by psilocybin, the active ingredient in magic mushrooms.
The volunteers were asked questions like whether they felt a loss of control or a loss of their sense of self, and whether they saw patterns and colours. Their answers matched up closely with the results of a 2013 study [open, DOI: 10.1523/JNEUROSCI.2063-13.2013] [DX] into the experience of taking psilocybin.
In a second experiment, 22 participants were asked whether they felt any sense of temporal distortion, or a warped sense of time. In this case the responses were similar to those recorded after watching control videos.
That would seem to suggest the researchers' machine can replicate some, but not all, the effects of being high on psychedelic drugs. However, only a few volunteers have been tested so far, and they were a different group to those quizzed on psilocybin back in 2013.
This is just the beginning for the technology – the system is very flexible and can be tweaked in all kinds of ways. In the future, participants could even get to adjust the parameters of the experience themselves.
With better hardware, the algorithms could be run in real time and applied to an augmented reality view instead of a pre-recorded panoramic video.
Also at Newsweek.
A Deep-Dream Virtual Reality Platform for Studying Altered Perceptual Phenomenology (open, DOI: 10.1038/s41598-017-16316-2) (DX)
[There's] been significant progress in unravelling the confusion over ketamine, with researchers identifying a ketamine derivative that tackles depression with far fewer side effects. And this week, a team of researchers at China's Zhejiang University announced that they've figured out where in the brain ketamine acts when it blocks depression, a finding that gives us significant insights into the biology of the disorder.
The new studies rely on the work of a number of other labs, which have identified a specific structure deep in the brain that's associated with depression. Called the lateral habenula, it's been associated with a variety of activities, the most relevant of which seems to be the processing of unpleasant outcomes and punishment. Electrodes implanted there have been used to relieve depression in at least one instance.
To test whether this might be the site of ketamine's activity, one team of researchers infused the drug directly into the lateral habenula of rats with depression-like symptoms; it blocked them. So did a separate chemical that inhibits the same proteins that ketamine acts on. Tracking the activity in the area, the researchers were able to show that there are bursts of activity in rats with symptoms of depression that are absent in healthy rats. The drugs that blocked depression suppressed these bursts.
Ketamine blocks bursting in the lateral habenula to rapidly relieve depression (DOI: 10.1038/nature25509) (DX)
Astroglial Kir4.1 in the lateral habenula drives neuronal bursts in depression (DOI: 10.1038/nature25752) (DX)
Related: FDA Designates MDMA as a "Breakthrough Therapy" for PTSD; Approves Phase 3 Trials
Study Suggests Psilocybin "Resets" the Brains of Depressed People
Ketamine Reduces Suicidal Thoughts in Depressed Patients