Scientists find no long-term benefit of using ketamine to treat depression

Ketamine does not provide additional long-term benefit for serious depression when given as repeated infusions. A randomized trial compared twice-weekly ketamine infusions as an add-on treatment for hospitalized patients with serious depression against a psychoactive comparison drug, midazolam, with follow-up after six months. Researchers found no significant differences between groups during the initial treatment phase or at the six-month follow-up, suggesting earlier estimates of ketamine's antidepressant efficacy may have been overstated. The study also reported that most participants correctly guessed their allocation despite blinding efforts, raising the risk of placebo effects and skewed results in trials where maintaining the blind is difficult.