As someone who was just released from prison myself (for a drug offense during college which led to my incarceration directly after surviving a stabbing) I can attest that the toxic environment of prison, including both rampant correctional officer cruelty and corruption coupled with horrifically sadistic and malevolent inmate culture, is a breeding ground for not just post-traumatic stress disorder but the continuation of and worsening of substance abuse disorders. Reform of the prison system in favor of renewed focus on rehabilitation and prison alternatives would benefit society far more than mass incarceration and it's pseudo-slavery reality as an overtly negative and archaic practice (particularly for majority non-violent offenses related to substance abuse).