Iatrogenic effects of group treatment for antisocial youths.

It has been argued that group treatment of antisocial adolescents may increase rather than decrease conduct problems. One mechanism that has been suggested to underlie this effect is "deviancy training," wherein during group sessions deviant peers reinforce each other's antisocial actions and words. These 2 hypotheses have important implications and warrant close review at conceptual and empirical levels. In this article, the authors present such a review. Conceptually, deviancy training potential of treatment sessions appears less significant than the more extensive peer influences outside treatment. Empirical findings previously cited in support of iatrogenic effects appear on close examination to provide little support. Finally, 17 of 18 new meta-analytic tests produced results not supportive of iatrogenic or deviancy training effects.