meta-analysis of 26 studies was conducted to assess whether more con~plex forms of psychotherapy would be superior to control treatments of either biofeedback, progressive n~uscle relaxation, or both. Consistent with hypotheses, more complex treatments provided a small, significant improvement over biofeedback and progressive muscle relaxation (r = ,091. A subset of the more co~nplex behavioral treatments accounted for most of this small incremental effectiveness of more con~plex treatments (r = .15). Possible sources of this incremental effectiveness arc discussed.