As interest has grown in the potential psychiatric applications of
ketamine, the number of registered clinical trials has grown substantially. Herein, we summarize and analyze clinical trials registered with ClinicalTrials.gov that assess the treatment of any
psychiatric disorder with
ketamine or
ketamine enantiomers (e.g.,
S-ketamine, R-
ketamine), with a focus on ongoing clinical trials. A ClinicalTrials.gov search on February 21, 2020 returned 140 registered trials. Frequency data was analyzed to determine the distribution of study designs. The majority of trials (70%) investigated the
therapeutic effect of
ketamine in
mood disorders (unipolar: 60%, bipolar: 0.7%, both: 5.7%). Suicidal ideation (13.1%),
post-traumatic stress disorder (5.4%), and
obsessive-compulsive disorder (3.6%) were also investigated. Intravenous (IV) administration was the most common route with 87% of the studies using IV
ketamine. Single-dose studies represented 50% of IV
ketamine studies. Few studies were assessing maintenance treatment. Most studies were phase I or II with few definitive phase III trials registered. Given the large number of ongoing studies assessing psychiatric application of
ketamine, researchers and relevant stakeholders should consider not only completed, published studies, but also ongoing registered studies in adjudicating the most relevant research questions. More definitive phase III trials and maintenance studies of IV
ketamine for
mood disorders are required, as numerous completed and ongoing studies have already assessed and demonstrated the proof-of-concept of acute
antidepressant effects in phase I and II trials.