A closed-loop implant detects a mood state and corrects it automatically

The step beyond stimulating a region all day: an implant that listens to the brain, recognises the pattern that comes with a bad state, and stimulates only then. In 2021 a San Francisco group reported one woman with severe depression whose implant detected her own signature of low mood and responded to it, and whose depression lifted within weeks and stayed better. It is one person, which is what a first human is.

What would count

A person with a mood disorder carries an implant that detects a brain signal tied to their mood state and delivers stimulation in response without a human in the loop, and their symptoms improve by a clinically meaningful amount on a standard scale, in a peer-reviewed report.

Who settles it: Peer-reviewed reports of the implanted patients; the regulator's approval record if it comes

Where it stands

First human. Reached on 4 October 2021, on the record of doi.org. Could move a stage within 5 to 20 years.

The last reading

Once a week every upgrade is read against the news, against what would count above. Open a line to see what that week held. Every reading of this upgrade is on this week's reading.

• 16 October 2026 Nothing new

  Nothing in the window. The registered closed-loop depression trials (the UCSF study using the NeuroPace device, due 2030; a Shanghai trial starting August 2026; two Pulvinar Neuro studies of a non-invasive version) have no published results, and nothing approaches a regulator's approval.

Notes

The record is the 2021 Nature Medicine report of a single patient. Closed-loop implants that respond to brain signals were already approved for epilepsy (the NeuroPace system, 2013), which is where the hardware came from; for mood the only record is this one and a few patients since.