Ketamine's Actions on Rumination Mechanisms as an Antidepressant

Summary

Rumination and anhedonia are two of the most common characteristics of depression that persist during remission and are not easily targeted by commonly prescribed antidepressants. Ketamine, an NMDA receptor antagonist, has emerged within the last decade as a potent, fast-acting antidepressant that can significantly improve anhedonia as early as two hours after a single infusion. The brain mechanisms, however, by which ketamine exerts its antidepressant action remain largely unknown. The aim of this study is to examine the early antidepressant action of ketamine, 2h post infusion, in patients who remitted from depression using fMRI. Participants are scanned while performing a personalised, autobiographical, emotional memory task and a monetary reward task. Ketamine is expected to reduce the activation of limbic areas such as the amygdala during emotional memory recall. Increased activations after ketamine are expected in reward processing areas, including striatal regions.

Timeline

Start

2014-09

Primary completion

2018-05

Completion

2018-05

Publications

• Background Zarate CA Jr, Singh JB, Carlson PJ, Brutsche NE, Ameli R, Luckenbaugh DA, Charney DS, Manji HK. A randomized trial of an N-methyl-D-aspartate antagonist in treatment-resistant major depression. Arch Gen Psychiatry. 2006 Aug;63(8):856-64. doi: 10.1001/archpsyc.63.8.856.
• Background Nolen-Hoeksema S. The role of rumination in depressive disorders and mixed anxiety/depressive symptoms. J Abnorm Psychol. 2000 Aug;109(3):504-11.
• Background Disner SG, Beevers CG, Haigh EA, Beck AT. Neural mechanisms of the cognitive model of depression. Nat Rev Neurosci. 2011 Jul 6;12(8):467-77. doi: 10.1038/nrn3027.
• Background Lally N, Nugent AC, Luckenbaugh DA, Ameli R, Roiser JP, Zarate CA. Anti-anhedonic effect of ketamine and its neural correlates in treatment-resistant bipolar depression. Transl Psychiatry. 2014 Oct 14;4(10):e469. doi: 10.1038/tp.2014.105.

Drugs

Indications

No indication recorded.