Action of Ketamine in Treatment-Resistant Depression
Status:
Completed
Trial end date:
2017-12-01
Target enrollment:
Participant gender:
Summary
Depression carries the largest burden of all medical disorders in middle to high income
countries, as determined by the World Health Organization. Despite many antidepressant
strategies, only a third of patients get well after their first treatment and a third remain
ill after several treatments. Moreover, antidepressant treatments all have a delayed action
ranging up to several weeks.
Ketamine (KET) has been used for decades as a sedative and anesthetic. In treatment-resistant
depressed patients(TRD), an intravenous dose much lower than necessary for anesthesia may
produce a robust antidepressant effect and may even abolish suicidal thoughts within hours,
peaking within 24 hours. But, its antidepressant effect generally lasts only days.Previous
studies examining KET in TRD have been critiqued for lack of an effective placebo measure due
to brief perceptual experiences associated with KET. Thus, the current study compares KET
against a short-acting sedative. The phases of this study compare response to a single KET
injection to 6 injections over 2 weeks. Next, KET responders are given 1 injection a week for
3 weeks of either KET or the sedative agent to determine if beneficial effects of KET are
maintained, and to assess duration of its benefits after repeated administration. The genetic
profile of patients for a substance promoting contacts between cells and brain will be
determined to investigate if response to KET could be predicted with that blood test. This
substance, as well as several chemicals that produce inflammation, will also be measured in
the blood to investigate their role in the effect of KET. Patients will receive, in total, no
more than the equivalent of two to three anesthetic dose of KET. Results from this study will
help establish the beneficial effects of a single KET injection as a rapid intervention for
major depression, and to investigate the possibility of obtaining a prolonged antidepressant
effect with repeated injections.