Light and Ion Maintenance In Treatment of Depression (LIMIT-D) Trial: Feasibility Study

Depression, or major depressive disorder (MDD), is a common and serious condition that is a leading medical cause of disability worldwide. Antidepressant medications are effective for MDD, but many people stop taking them too soon. Clinical guidelines recommend up to 24 months of "maintenance" treatment to prevent relapse (return of depressive symptoms) but studies show that 70% of people abandon medications after only 3 months of treatment, with high risk of relapse and problems in social and work functioning. Since many people prefer non-medication treatments, we will test two such treatments, light therapy and negative ion therapy, to see if they can substitute for antidepressants to prevent relapse. Because there are no previous studies on these treatments for maintenance, we will do a smaller "feasibility" study to see if people volunteer for the study and use study treatments properly, before a larger study can be done. For example: when people are recovered from depression, will they agree to stop medications to use another treatment? People will use light therapy and negative ion therapy daily during acute treatment, but will they use them during maintenance? To answer these questions and test feasibility, we will find 100 adults with recurrent MDD who have taken antidepressants for 3 to 12 months and are no longer depressed. We will randomly assign them (like flipping a coin) to use either a light device or a negative ion device at home for 30 minutes a day, 5 days a week. The devices are adjusted so that only half give active light or ions and participants will not be able to tell which are active and which are not. The antidepressants will be slowly stopped over 2-6 weeks. We follow participants for up to 52 weeks to see whether the active light or ion therapy can prevent relapses compared to the not-active treatments. The results of the feasibility study will provide valuable information for the full trial that may involve more than 300 participants.