Date of Award

Fall 12-2011

Degree Type

Masters Thesis

Degree Name

Master of Arts (MA)



Committee Chair

David K. Marcus

Committee Chair Department


Committee Member 2

Tammy D. Barry

Committee Member 2 Department


Committee Member 3

Virgil F. Zeigler-Hill

Committee Member 3 Department



Psychotherapy has been proven effective in treating a variety of mental health issues. However, there is disagreement in psychotherapy research about whether or not factors common to all psychotherapies or specific ingredients within a treatment package are responsible for successful treatment outcomes. Component studies are research designs specifically aimed at identifying the mechanisms of change in a full treatment package. Component studies do this by comparing the differences in outcome among dismantled treatment components and the full treatment protocol. The present metaanalytic review of component studies examined whether or not differences between these two treatment groups generally exist. Fifty-nine component studies were analyzed to determine the difference in the outcome between dismantled treatments and full treatment packages. Studies were coded on a number of variables including sample size, intervention type, treatment problem, gender, and age. As hypothesized, results from 59 comparisons of post-treatment score differences revealed that there are not differences between the full treatment package and the component treatment (d = -.005). These results mirrored the findings from Ahn and Wampold’s (2001) original meta-analysis of 20 component studies. However, there was significant heterogeneity among these studies, with treatment effectiveness moderated by age (i.e., older clients benefiting more from the full treatment packages; β = -.316). The present study also examined treatment outcomes at follow-up. The follow-up results from 44 comparisons of component groups and full treatment package groups indicated that the full treatment package was more effective than the component group (d = -.157). The results from this study suggest that specific ingredients in psychotherapy packages do have an effect, but these effects may not be apparent at post treatment, and, instead, will appear in follow-up outcomes.

Included in

Psychology Commons