LINCOLN, Neb. (AP) — A new report says Nebraska is overusing solitary confinement on juveniles and warns that policies on how it is enforced vary widely throughout the state.

The report released Monday by the ACLU of Nebraska says some juveniles have been placed in isolation for minor rule violations, such as talking back to staff members, having too many books or refusing to follow directions.

The group also found that the maximum lengths of time in solitary differ by facility, from a little as five days to as many as 90.

National child psychiatry groups have warned that prolonged stays in solitary confinement do more harm than good for juveniles.

The ACLU of Nebraska report was based on record requests filed with each of the state’s nine juvenile detention centers.