What is the evidence for evidence-based treatments? A hard look at our soft underbelly.

In the rising quest for evidence-based interventions, recent research often does not give adequate attention to "nonspecific therapeutic factors," including the effects of attention, positive regard, and therapeutic alliance, as well as the effects of treatment dose, intensity and actual processes mediating therapeutic change. To determine the extent to which recent clinical trial designs fully this problem, the authors conducted a systematic review of Psych-Lit/Medline of all controlled child psychotherapy treatment studies from 1995 to 2004. A total of 52 studies were identified that met review criteria: two or more therapy conditions and random assignment of participants to intervention groups. Of the 52 studies, one group (n = 29) compared a presumably active treatment with 1 or more similarly intensive treatments (often an attention control group) presumably not containing the active therapeutic ingredients. Of these, 14 studies found evidence of consistent differences between the two groups, whereas 15 did not. An additional group of studies (n = 27) compared therapy groups with different levels of intensity and "dose" of the putatively active treatment; 13 of these found evidence of the effects of different levels of treatment dose/intensity on outcomes and 14 did not. Four studies met criteria for inclusion in both groups. Across both groups of studies, when positive effects were found, few studies systematically explored whether the presumed active therapeutic ingredients actually accounted for the degree of change, nor did they often address plausible alternative explanations, such as nonspecific therapeutic factors of positive expectancies, therapeutic alliance, or attention. Findings suggest that many child psychotherapy treatment studies have not inadequately controlled for nonspecific factors such as attention and treatment intensity and have failed to assess specific mediators of change. Specific recommendations for future studies are offered, specifically: 1. Initial specification in study design how investigators will test if the intervention is efficacious over and above the effects of positive expectancies, positive regard, or attention; 2. Planned (rather than post hoc) analyses to explore whether and how a given treatment's specific ingredients or the overall intensity of its "dose" are related to treatment outcomes; 3. More studies conducting head-to-head tests of different types but equally credible forms of treatment, with planned analyses testing different mechanisms of change 4. When positive effects of a treatment vs. a control are found, systematic elimination of specific, competing hypotheses of reasons for treatment efficacy (e.g., attention, therapeutic alliance, face validity of treatment and client's treatment expectations, changes in self-efficacy), and 5. When negative effects are reported, appropriate analyses to address alternative explanations (lack of power, floor or ceiling effects, mediator analyses to address possible fidelity or adherence problems, therapist effects, absence of main effects but possible subgroup/moderator effects, etc.).