Effect of Ketamine in the Treatment of Patients with Major Depressive Disorder

Major depressive disorder is a common and destructive mental disorder with relatively long episodes, high tendency to be chronic and recurrence, and responsible for many physical and mental disabilities that has the lifetime prevalence of about 17% to 19%. With regard to the improvement of non responder patients to routine treatment following a single dose injection of ketamine, this study was done to investigate the effect of ketamine on patients with major depressive disorder (MDD).

This clinical trial study (semi-experimental design) was performed on 60 patients with MDD according to DSM IV-TR criteria. A single intravenous dose of ketamine (0.5 mg/kg) was given to the patients. Depression level of all patients was assessed before injection, on the days 2 and 7 after injection of ketamine and at the end of 1st and 2nd months based on Beck and Hamilton Depression Scale. Criteria for response to treatment with ketamine was reduction of 50% or greater in Hamilton and Beck scores.

The results showed that mean score for Hamilton test before injection, on the days 2 and 7 after injection was 28.71±9.12, 20.57±10.88 and 16.85±10.70, respectively and mean score for Beck test before injection, on the days 2 and 7 after injection was 32.28±13.96, 25.05±14.10 and 19.71±13.40, respectively that significantly decreased as compared to before injection (p<0.05). The results of the scores decreased over 50% in about 20% of patients on the second day and 40% on the seventh day after injection of ketamine. Improving symptoms of depression in these patients was not associated with other variables such as age, sex, marital status, residence place, education level and season of injection.

With regard to easy administration, rapid effect and appropriate duration of action of intravenous single dose of ketamine in patients with MDD, it can be a good alternative for acute phase treatment of major depression.