Another great Scandinavian linkage study compares methods to reduce violent reoffending after release from Swedish jails, both across and within individual ex-prisoners. The results confirm the results of RCTs in non-prisoner populations – psychotropic drugs reduce violent reoffending by about a third, and drugs to combat addiction by about 40% (using within person analysis to control for many sources of confounding, such as genetic predisposition, adverse upbringing, etc.). Similar results were obtained in the (potentially more confounded) between person analysis. Anti-depressant drugs had no apparent effect on reoffending in any analysis. Of course, this is an observational study and reverse causality, even within individuals is possible, but it is the best information we are likely to have for some time, and is relevant to attempts to reduce the duration of incarceration in many countries, including England. The fact that the results mirror experimental studies in at-risk people who had not been to prison adds verisimitude to the findings.
— Richard Lilford, CLAHRC WM Director
- Chang Z, Lichtenstein P, Långström N, Larsson H, Fazel S. Association Between Prescription of Major Psychotropic Medications and Violent Reoffending After Prison Release. JAMA. 2016; 316(17): 1798-1807.
- Chen Y-F, Hemming K, Chilton PJ, Gupta KK, Altman DG, Lilford RJ. Scientific hypotheses can be tested by comparing the effects of one treatment over many diseases in a systematic review. J Clin Epidemiol. 2014; 67: 1309-19.