By now it should be clear to readers that the self-help movement in mental health is represented by an enormous range of resources available, along various continua of validity and reliability. One of the most important areas in need of investigation is the area of patient–treatment matching with respect to SH. More specifically, who is most likely to benefit by SH? What are the most reliable indicators of assignment to SH? When are SH interventions most indicated? To answer these questions, a theory of SH and SC based on what is known about patient–treatment matching might more likely prove beneficial in the assignment of the various SH resources available today (e.g., Harwood & Beutler,2008 Beutler & Harwood, 2000; Beutler, Clarkin, & Bongar, 2000; Beutler & Clarkin, 1990).