Here are some scientific articles, but there is actually more research going on in this field.
Antidepressant effects of ketamine in depressed patients. Berman, R. M.; Cappiello, A.; Anand, A.; Oren, D. A.; Heninger, G. R.; Charney, D. S.; Krystal, J. H. Abraham Ribicoff Center Clinical Neuroscience Research Unit of the Connecticut Mental Health Center, New Haven, CT, USA. Biological Psychiatry (2000), 47(4), 351-354. Publisher: Elsevier Science Inc., CODEN: BIPCBF ISSN: 0006-3223. Journal written in English. CAN 133:68749 AN 2000:126948 CAPLUS
Abstract
Subjects with major depression completed 2 test days that involved i.v. treatment with ketamine-HCl [an N-methyl-D-aspartate (NMDA) receptor antagonist] (0.5 mg/kg) or saline solns. under randomized, double-blind conditions. The subjects evidenced significant improvement in depressive symptoms within 72 h after ketamine but not placebo infusion. These results suggest a potential role for NMDA receptor-modulating drugs in the treatment of depression.
Small-dose ketamine improves the postoperative state of depressed patients. Kudoh, Akira; Takahira, Yoko; Katagai, Hiroshi; Takazawa, Tomoko. Department of Anesthesiology, Hakodate Watanabe Hospital, Hirosaki, Aomori, Japan. Anesthesia & Analgesia (Baltimore, MD, United States) (2002), 95(1), 114-118. Publisher: Lippincott Williams & Wilkins, CODEN: AACRAT ISSN: 0003-2999. Journal written in English. CAN 137:134991 AN 2002:579114 CAPLUS
Abstract
We investigated whether ketamine is suitable for depressed patients who had undergone orthopedic surgery. We studied 70 patients with major depression and 25 patients as the control (Group C). The depressed patients were divided randomly into two groups; patients in Group A (n = 35) were induced with propofol, fentanyl, and ketamine and patients in Group B (n = 35) were induced with propofol and fentanyl, and all patients were maintained with 1.5%-2.0% isoflurane plus nitrous oxide. The mean Hamilton Depression Rating (HDR) score was 12.7 ± 5.4 for Group A and 12.3 ± 6.0 for Group B 2 days before surgery and 9.9 ± 4.1 for Group A and 14.4 ± 3.8 for Group B 1 day after surgery. The HDR score in Group A 1 day after surgery was significantly (P < 0.05) lower than that in Group B. The HDR score in Group C was 4.2 ± 1.7 2 days before surgery and 4.8 ± 1.6 1 day after surgery. Depressed mood, suicidal tendencies, somatic anxiety, and hypochondriasis significantly decreased in Group A as compared with Group B. Postoperative pain scores in Group A at 8 and 16 h after the end of anesthesia were 26.6 ± 8.7 and 24.9 ± 8.2, resp., which were significantly (P < 0.05) lower than 34.3 ± 12.0 and 31.1 ± 8.8 in Group B. In conclusion, small-dose ketamine improved the postoperative depressive state and relieved postoperative pain in depressed patients.