
In small doses, the anesthetic ketamine is a mildly hallucinogenic party drug known as “Special K.” In even smaller doses, ketamine relieves depression — abruptly and sometimes dramatically, steering some people away from suicidal thoughts. Studies indicate that ketamine works in 60 to 70 percent of people not helped by slower-acting SSRIs, the usual drugs for depression.
Two ketamine-like drugs are in the clinical pipeline, and, as of this week, one appears close to FDA approval. With no significant new antidepressant in more than 30 years, anticipation is high. Yet no one has pinned down how low-dose ketamine works. Studies have implicated various brain neurotransmitters and their receptors — serotonin, dopamine, glutamate, GABA receptors, opioid receptors — but findings have been contradictory.
“We felt it was time to figure this out once and for all,” says neuroscientist Takao Hensch, PhD.
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