Substance abuse programs in prison differ from those outside the community in that a lot of prisons offer inmates a chance to attend classes or treatments that will inevitably benefit them without the pressures of outside influences where substances are easily attainable. In the outside world inmates are in a sense like school age kids in that they can be pressured (peer pressure) into continuing their addictions and this can be extremely hard for an inmate.
A community based program would be more beneficial though because of being watched and an ex-inmate can have the feeling of being in a safe environment as well as having all of their information kept in confidence. A community based program also gives an inmate a chance to realize their wrong doings and allow them a chance to see that they can live in society without substances to get through their days.
A coerced treatment can cause an inmate to resist society if they are released and have a high amount of resentment. When an inmate is coerced into treatments there is a higher potential for them to fail versus succeeding. On the other hand, voluntary treatments will allow for a more positive influence from the inmate. When an inmate is going through a treatment on a voluntary basis he or she will be more responsive as well as feel more motivated to complete the treatment. This will undoubtedly have a more positive outcome and allow for success.