You need to look harder. Schizophrenia and psychotic features are relative contraindications for use of ketamine per APA guidelines. “It is unclear whether patients with depression that is not treatment- refractory or patients with other psychiatric illnesses are ap- propriate candidates for ketamine treatment, and extreme caution must be exercised in patients with psychotic or substance use disorders.”

Side-effects associated with ketamine use in depression: a systematic review, Short 2018.

To summarize: A review of 60 studies found dissociation and psychotomimetic effects >70 percent of the studies at varying rates. And note that the time courses of observation were variable. Furthermore most of these studies excluded participants with psychotic features or known psychotic disorder.

But for any provider considering ketamine this is literally top of the list in consideration of adverse effects.