• clinical complexity;
  • empirically supported treatments;
  • experimental research;
  • treatment manuals

Ruscio and Holohan (2006) address the challenges of applying empirically supported treatments (ESTs) with complex patients (e.g., those with comorbid conditions). Many clinicians, in such instances, abandon ESTs on the assumption that treatment manuals do not apply. In the present commentary I argue that although ESTs provide the best available guidance for how to treat many psychological disorders, effective treatment does not require rigid adherence to treatment manuals if the clinician is able to develop a case formulation on the basis of a functional analysis of behavior and apply empirically supported treatment procedures accordingly. The development of exposure and response prevention for obsessive-compulsive disorder is presented as an example of how knowledge of basic cognitive and behavioral processes transcends ESTs and their manuals. I conclude that it is important for beginning therapists to learn to apply principles based on these processes rather than to rely exclusively on treatment manuals.