the prison litigation reform act (plra) further complicates inmates’ ability to claim that solitary confinement's psychological damage constitutes cruel and unusual punishment. section 1997e(e) of the plra states that this demonstrates that the eighth amendment provides “greater protection” against physical injury than against mental pain. therefore, unless a prisoner can demonstrate physical injury as a result of solitary confinement, he or she is unable to recover damages for any “mental or emotional injury” the confinement causes. as a result, the eighth amendment has not always been proven to be the most effective approach to argue against the practice of solitary confinement.