Conditions: Major Depressive Disorder
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 37
Healthy volunteers: no

Brief summary:
Ketamine infusions resulted in an acute reduction in global depression scores and in severity of suicidal ideation. The investigators therefore plan to investigate the feasibility and efficacy of repeated intravenous administration of ketamine in severely depressed, treatment resistant patients. The results of the study could lead to development of new strategies for treating depression.

Detailed description:

Arms:
arm 1: Subject will receive 6 infusions of ketamine over three weeks. arm 2: Subjects will receive 6 infusions of normal saline over 3 weeks.

Interventions: intervention 1: Ketamine intervention 2: Placebo
Intervention descriptions: intervention 1: ketamine infusions twice a week for three weeks, total of 6 infusions as augmentation of ongoing antidepressant regimen. intervention 2: None

Protocol document: