In its latest Research in Review, the Pennsylvania Department of Corrections presents a summary of findings from a study of long term outcomes of therapeutic community drug treatment programs in the Department. Performed by Wayne Welsh, Ph.D., of Temple University, the study was begun in 1998 and continues to the present, although this summarizes a final report. The Department characterizes the study as "one of the longest, largest and most rigorous evaluations of prison TC. Thus, the research done here is valuable not only for Pennsylvania, but for the correctional profession nationwide." The full report is also available from the DOC's site.