There are several factors at play here. One is the interaction of the medical profession’s prestige with its arrogance: Patients are deferential to physicians and their advice, and the normal skepticism that regulators and oversight authorities would bring to, say, the manufacture of automobile airbags or the organization of commercial banks, often is partly suspended for physicians, who occupy the sanctum sanctorum in our national cult of expertise.

A second factor is that patients who are not deferential often are patients who complain. You know who doesn’t complain? A patient who is high out of his mind on oxy or knocked on his ass by Xanax. A stoned patient is a cooperative patient.

The underlying moral calculus here will be familiar to anybody who has spent any time on a farm — or anybody who has had a pet dog, for that matter. When a sick collie or an injured horse is in pain and beyond help, we put them down to end their suffering. We do this in the name of mercy.

But veterans with PTSD aren’t injured racehorses. Poor people, alcoholics, and the mentally ill aren’t our pets, and we owe to them more than the simple pharmaceutical easing of their pain on their way to an early death via opiate toxicity.