Öst, L. G. (2008). Behaviour Research and Therapy, 46(3), 296-32.
During the last two decades a number of therapies, under the name of the third wave of cognitive behavior therapy (CBT), have been developed: acceptance and commitment therapy (ACT), dialectical behavior therapy (DBT), cognitive behavioral analysis system of psychotherapy (CBASP), functional analytic psychotherapy (FAP), and integrative behavioral couple therapy (IBCT). The purposes of this review article of third wave treatment RCTs were: (1) to describe and review them methodologically, (2) to meta-analytically assess their efficacy, and (3) to evaluate if they currently fulfil the criteria for empirically supported treatments. There are 13 RCTs both in ACT and DBT, 1 in CBASP, 2 in IBCT, and none in FAP. The conclusions that can be drawn are that the third wave treatment RCTs used a research methodology that was significantly less stringent than CBT studies; that the mean effect size was moderate for both ACT and DBT, and that none of the third wave therapies fulfilled the criteria for empirically supported treatments. The article ends with suggestions on how to improve future RCTs to increase the possibility of them becoming empirically supported treatments.
Bratton, S. C.; Ray, D., Rhine, T. & Jones, L. (2005). Professional Psychology: Research and Practice, 36(4), 376-390.
The efficacy of psychological interventions for children has long been debated among mental health professionals; however, only recently has this issue received national attention, with the U.S. Public Health Service (2000) emphasizing the critical need for early intervention and empirically validated treatments tailored to children's maturational needs. Play therapy is a developmentally responsive intervention widely used by child therapists but often criticized for lacking an adequate research base to support its growing practice. A meta-analysis of 93 controlled outcome studies (published 1953-2000) was conducted to assess the overall efficacy of play therapy and to determine factors that might impact its effectiveness. The overall treatment effect for play therapy interventions was 0.80 standard deviations. Further analysis revealed that effects were more positive for humanistic than for nonhumanistic treatments and that using parents in play therapy produced the largest effects. Play therapy appeared equally effective across age, gender, and presenting issue
Lipsey, M. W. &Wilson, D. B. (1993). American Psychologist, 48(12), 1181-120.
Conventional reviews of research on the efficacy of psychological, educational, and behavioral treatments often find considerable variation in outcome among studies and, as a consequence, fail to reach firm conclusions about the overall effectiveness of the interventions in question. In contrast, meta-analysis reviews show a strong, dramatic pattern of positive overall effects that cannot readily be explained as artifacts of meta-analytic technique or generalized placebo effects. Moreover, the effects are not so small that they can be dismissed as lacking practical or clinical significance. Although meta-analysis has limitations, there are good reasons to believe that its results are more credible than those of conventional reviews and to conclude that well-developed psychological, educational, and behavioral treatment is generally efficacious