A security fence surrounds the inmate housing on New York's Rikers Island correctional facility in New York. (Bebeto Matthews/Associated Press)

THE FEDERAL government should be leading the effort to end the abuse of isolating prisoners from meaningful social interaction and other basic needs. Instead, the federal system’s practices are clearly contributing to the morally inexcusable overuse of prisoner isolation.

Prisoner segregation — also known as solitary confinement — is the sort of extreme punishment, an assault on the mind, that should be reserved for a tiny number of very dangerous people. Instead, thousands of U.S. prisoners live in solitary confinement for unconscionable lengths of time. A new government report found that the population of inmates in isolation in federal prisons includes both the dangerous and the seriously mentally ill.

Indeed, federal authorities hold a large number of people in unnecessarily harsh conditions: prisoners awaiting processing, prisoners being investigated for misconduct and even prisoners held in isolation ostensibly for their own protection. Conditions include near-constant confinement to cells, restricted access to telephones, few activities and only a few hours of out-of-cell recreation a week held in special “cages.” Even when prisoners have cellmates, that sort of isolation no doubt affects the mind. “Inmates spending extended periods of time in close confinement with little social interaction or skill-building programming are seriously unprepared for reentry and re-socialization,” the report notes, criticizing the bizarre fact that many facilities don’t try to ease inmates’ reintroduction to less restrictive circumstances — or into the community.

The worst failings the report documents concern the treatment — or lack thereof — of the mentally ill. Mandatory isolation and mental illness can be a toxic combination, but it’s inadequately monitored in the federal system, in some cases by graduate students. The investigators, independent contractors commissioned by the Federal Bureau of Prisons, discovered prisoners with undiagnosed mental illnesses and many others who were diagnosed inaccurately. Some inmates had conditions that should have automatically precluded them from segregation.

Federal prisons need to conduct real evaluations before isolating people, holding private, face-to-face interviews with prisoners. They need to offer serious out-of-cell treatment. Federal authorities should start by conducting full evaluations of everyone currently in isolation to determine whether they should be in a mental health facility instead.

But this should represent only the beginning of the reexamination. Rather than settling for a few incremental changes, the federal government should insist that segregation is not an appropriate punishment or order-keeping strategy except in the rarest cases. The federal government should be leading states, some of which are even more punitive, and some of which have adopted notably more humane practices. The Bureau of Prisons should set a better example, and then Congress should provide incentives for states to reduce the number of inmates they keep in segregation and improve the conditions of those they still isolate.