A word of caution: Ketamine treatment is far from standardized. Most of the clinical studies I've read aren't using doses that produce profound psychedelic trips. The more professional clinics seem to have settled on dosing regimens that produce mild impairment, but not the full-blown dissociative trips described in many of these articles.
Meanwhile, there are a lot of questionable ketamine clinic providers popping up all over the country that give much higher doses. Some of them promote the psychedelic angle heavily in their marketing materials, as it has become a major revenue generator from patients who read articles like this one. While a single medium to high dose of ketamine may not produce marked negative effects, some of the high-dose, repeat-dosing regimens used by alternative therapy providers are in the range where I'd begin to be very concerned about lasting damage.
I would strongly caution anyone curious about ketamine treatment to stick to the lower-dose clinics and providers. Avoid anyone trying to sell you on "psychedelic therapy" or who has a reputation on the internet of providing excessively large doses. Also keep in mind that the antidepressant effects are short-lived, so plan to engage with traditional long-term treatment (therapy and/or antidepressants) to create a lasting strategy for yourself when the short-term effects of the ketamine wear off.