Shiroma, Johns et al. Augmentation of response and remission to serial intravenous subanesthetic ketamine in treatment-resistant depression” Journal of Affective Disorders. 2014 Feb;155:123-9.
Highlights:
- In this study, we determined antidepressant response and remission to six consecutive ketamine infusions while maintaining stable doses of the antidepressant regimen. We also examined the trajectory of response and remission and the time to relapse among responders.
- TRD subjects had at least a 2-month period of stable dose of antidepressants. Subjects completed six IV infusions of 0.5 mg/kg ketamine over 40 min on a Monday–Wednesday–Friday schedule during a 12-day period participants meeting response criteria were monitored for relapse for 4 weeks.
- Repeated infusions achieved superior antidepressant outcomes as compared to a single infusion with different trajectories of response and remission.
Results:
Fourteen subjects were enrolled. Out of twelve subjects who completed all six infusions, eleven (91.6%) achieved the response criterion while eight (66.6%) remitted. After the first infusion, only three and one out of twelve subjects responded and remitted, respectively. Four achieved response and six remitted after 3 or more infusions. Five out of eleven subjects remain in response status throughout the 4 weeks of follow-up. The mean time for six subjects who relapsed was 16 days.
Conclusions:
The safety and efficacy of repeated ketamine infusions were attained without the medication-free state in patients with TRD. Repeated infusions achieved superior antidepressant outcomes as compared to a single infusion with different trajectories of response and remission. Future studies are needed to elucidate neural circuits involved in treatment response to ketamine.
