Time-Course of Depression Improvement With Ketamine Adjunction in Electroconvulsive Therapy.

In a recent and elegant meta-analysis, McGirr et al 1 assessed ketamine adjunction in electroconvulsive therapy (ECT), which is frequently used in pharmacoresistant major depressive disorder. Because ketamine demonstrated good efficacy in depression, some studies assessed the potentiation of ECT by using ketamine as the anesthetic agent. In their meta-analysis, the authors included 5 randomized controlled trials comparing the antidepressive effects of ketamine + ECT (K + ECT) versus another anesthetic agent + ECT (AAA + ECT). No significant difference in remission or response rates, or in depressive symptoms was observed with or without ketamine adjunction in ECT. However, results from many studies argued for a possible ketamineinduced improvement of depressive symptoms during the very first week of treatment. Thus, a time-course of ketamine effects in ECT may provide relevant information in addition to the data supplied in the meta-analysis. To investigate the time-course of ketamine’s action, we searched the MEDLINE and PsycINFO databases through January 2015. Details concerning the data sources, study selection process (Figure S1), data extraction, and the data analyses were given in Supplemental Digital Content 1 (http://links.lww.com/JECT/A41). With one exception, original means and SDs for the depression scores were kindly provided by the authors of the original publications. Standardized mean differences (SMD) between the depression scores in K + ECT and AAA + ECT groups were calculated at different time points, as follows: (1) baseline, (2) 1 or 2 ECTs, (3) 3 or 4 ECTs, (4) 5 or 6 ECTs, and (5) post-ECT (see Supplemental Digital Content 1, http://links.lww.com/JECT/A41). Six trials, including a total of 185 patients, were included in our meta-analysis. The main demographic and clinical characteristics of the included studies were described in Table S1. Three trials showed no difference between the ketamine and control groups, 1 trial reported improvement in the depression score on the first day after ECT, and 2 other trials described