Ketamine for the treatment of depressive and negative symptoms in patients with schizophrenia: a randomized controlled cross-over pilot study

Randomised, double-blind, two-period crossover trial in Austria (n=20) comparing IV esketamine (Ketanest S 25 mg/ml) with an active diphenhydramine placebo (Dibondrin) to assess efficacy on negative and depressive symptoms in schizophrenia-spectrum disorders.

Primary outcomes are change in the Scale for the Assessment of Negative Symptoms (SANS) and MADRS across treatment periods; secondary outcomes include PANSS, CDSS, CGI and CADSS with repeated assessments during and after each treatment period.