"God, grant me the serenity to accept the things I cannot change, the courage to change the things I can, and the wisdom to know the difference." This healing prayer has been adopted by Alcoholics Anonymous and other twelve-step programs and, with the advent of acceptance and commitment therapy (ACT), has found its way into modern behavioral science. The Wisdom to Know the Difference offers readers a unique path to treating alcoholism and drug addiction through ACT, which has been proven to be clinically effective for the treatment of alcoholism and substance abuse. This workbook unifies the most widely practiced method of substance abuse treatment, the twelve-step program, with an empirically supported psychotherapeutic model, acceptance and commitment therapy (ACT). Each component of this ACT treatment plan has an explanation rooted in basic behavioral science, and readers will learn how these components fit into the twelve steps in Alcoholics Anonymous and similar programs. Written by Kelly Wilson, cofounder of the ACT treatment model, and Troy DuFrene, this workbook is accessible for all reading levels and can be used by those suffering from all forms of substance abuse.