Scientists still don’t know what gives ketamine its antidepressant effect. Stressed mice might offer a clue

As ketamine makes waves in the field of mental health, there’s a mystery around the drug that continues to elude scientists: how, exactly, it works in the brains of people with depression.

Now, scientists have uncovered a process that might contribute to ketamine’s antidepressant effect. In new research in mice published Thursday in Science, researchers report that ketamine appears to spark the growth of neural connections that had been diminished by chronic stress. They also discovered that the survival of those new connections — known as synapses — seems to be critical to maintaining some of ketamine’s effects.

“To the extent that what we’re modeling in the brains of mice captures something that’s happening in the brains of depressed people, this could