Treatment-resistant depression affects one in three of the estimated 16.2 million adults in the US who have suffered at least one major depressive episode.

For them, two or more therapies have failed and the risk of suicide is much greater. It’s a grim prognosis.

As there are few therapies for depression that resists treatment, the Food and Drug Administration in the US has been considering a new treatment called esketamine.

Last month, I participated in the FDA review of this drug. Practically speaking, esketamine is essentially the same as ketamine, which is a pain killer with hallucinogenic effects and used illegally.