SOLITARY CONFINEMENT is one of the cruelest fates that can befall a prisoner — so cruel, in fact, that the Supreme Court nearly declared it unconstitutional in 1890. Unfortunately, this particular punishment has remained a bitter reality of the U.S. correctional justice system in the century that’s followed, eliciting continual outrage from advocacy groups and inmates alike.

Locked in concrete cells without sunlight or human contact for up to 23 hours per day, inmates become prisoners of their own minds, trapped in their own anxieties, suspicions and fears. Although most of these prisoners will be re-introduced to the general population, it’s not surprising that nearly half of all prison suicides occur in solitary confinement. It’s a tactic that breaks people, often beyond repair.

Little wonder, then, that some 30,000 prisoners in California state prisons went on a hunger strike this summer to protest the use of solitary confinement. Protest organizers called off the strike after California lawmakers promised to hold hearings on the state’s so-called supermax prisons and their use of solitary confinement.

In Virginia, however, a hunger strike wasn’t necessary to highlight the cruelty of this punishment. In the past two years, the state’s Corrections Department has taken the initiative to institute a program at the Red Onion and Wallens Ridge state prisons that provides inmates in “administrative segregation” the opportunity to work their way out of crippling isolation.

Known as “step-down,” the program offers classes to inmates officials have identified as having potential for successful development. Sessions encourage them to confront issues such as substance abuse and anger management, and they’re eased back into regular human contact. Initially, the inmates participate in group sessions in adjacent individual cells; later they are handcuffed to a “security chair” for the sessions. The final step is joining the general prison population.

In 2011, Virginia had 468 prisoners locked away in solitary confinement at those two prisons. As of last month, only 179 remained. That’s a staggering 62 percent decrease, accompanied by an even more staggering 79 percent decrease in the number of grievances prisoners have issued since the “step-down” program began.

Those statistics are a testament to the viability of a solution to the many problems of solitary confinement as much as they evince the humanity of the state’s Corrections Department.

Besides, the long-term costs of allowing the status quo to remain unchallenged are simply too high. As state Delegate Patrick A. Hope (D-Arlington) and state Sen. Adam P. Ebbin (D-Alexandria) pointed out in The Post, nearly 90 percent of Virginia’s prisoners will be released. In their words: “Who would you rather have living in your community: a person who sat stewing year after year in near-total isolation or one who has spent his time learning new ways to communicate, solve problems and control his anger?”