New hope for tough depression cases: experimental Add-On therapy enters testing

This study is testing whether adding an investigational drug called SPN-821 to a person's current antidepressant helps reduce symptoms of major depression more effectively. It will involve about 230 adults whose depression hasn't improved enough on their current medication alone. Participants will receive either SPN-821 or a placebo (inactive substance) twice a week for four weeks, in addition to their regular treatment, to see if it makes a difference.