Roughly 10 percent of the U.S. population is afflicted with major depressive disorder at any given time, and up to 20 percent will exhibit MDD symptoms over their lifetimes. Yet despite its prevalence, methods to treat MDD often fall short for a not-insignificant portion of the population. Antidepressants—the standard of treatment—don’t work for 30 percent with MDD.

When infused at a low dose, ketamine shows remarkable efficacy as a rapidly acting antidepressant, with effects observed within hours even in patients who have been resistant to other antidepressant treatments. However, consistent infusions of ketamine are needed to maintain symptoms at bay, which could result in side effects, such as dissociative behaviors and the possibility of addiction, and stopping treatment can result in relapse.

In a new study published in Science, Lisa Monteggia’s and Ege Kavalali’s labs show that it is feasible to substantially extend the efficacy of a single dose of ketamine from its current duration of up to a week to a longer period of up to two months.