Elena Lister, a Columbia University psychiatrist who specializes in grief, says a healthy level of denial of death is necessary. But now, Lister says, her colleagues are talking about a pandemic of loss being felt throughout society, the product of mass death compounded by stunted grief.

In particular, doctors like Lister worry about complicated grief, a psychiatric disorder diagnosed when, one year after a loss, the pain of acute grief has not begun to subside. About 10% of mourners have it; they remain severely socially withdrawn and desperate, unable to resume their life activities.

The pandemic created particularly…