You recall those 500-odd ketamine clinics we recently learned are already in operation in the United States? The ones that seemingly popped up overnight, to serve persons suffering from a host of psychological problems and disorders?

Here’s an update on one such provider, the nation’s largest. They’ve abruptly shut down all operations, leaving patients in the lurch.

I’m terrified’: Patients scramble for treatment after 13 ketamine clinics shut down

The manner of their demise reminded me of how some trendy restaurants simply lock their doors when the business fails. No warning, just a notice posted at the entrance: “To our employees. You don’t work here anymore. Thanks for your support.”

This chain was a multi-state operation, so the notice arrived in a surprise email to staff at ketamine centers in Arizona, Nevada, Texas, Washington, Utah, Colorado, Minnesota, and Illinois.

Oh wait, I forgot Florida. There too.

It appears to be a familiar tale of eager entrepreneurs who, perhaps intoxicated with their early success, brought in new money via an investment firm that was looking to stake out territory in the hot new ketamine industry. But the owners underestimated the funds they would need to sustain an expanded network of clinics. They also seem to have overestimated the help they could expect from the new investors. Pretty soon, red ink was flowing through the quarterly financial reports.

Desperate, the founders tried to stem the tide using their own personal funds. Then those ran out. Next step: notify the patients. So sorry, let us know where you want your file sent.

This is such a common story in the world of startups that I wouldn’t be surprised if other companies run into the same problems in future, with the same result. Business columnists like to call this a ‘shakeout’. Patients are likely to be less forgiving.

A number of state governments are at least considering laws to allow the use of ketamine and other psychedelics at so-called ‘wellness’ clinics. Apparently the clinics themselves have been marketing their services in terms of healing powers for an array of mental disorders — PTSD, depression, what have you. Is that FDA approved? Nope. Is the clinic regulated, along the lines of a medical facility? Seems it isn’t. If something goes wrong, what recourse do patients have? Depends.

Who ever decided this was a good idea?