Book excerpt: Motivation is key to substance use behavior change. Counselors can support clients' movement toward positive changes in their substance use by identifying and enhancing motivation that already exists. Motivational approaches are based on the principles of person-centered counseling. Counselors' use of empathy, not authority and power, is key to enhancing clients' motivation to change. Clients are experts in their own recovery from SUDs. Counselors should engage them in collaborative partnerships. Ambivalence about change is normal. Resistance to change is an expression of ambivalence about change, not a client trait or characteristic. Confrontational approaches increase client resistance and discord in the counseling relationship. Motivational approaches explore ambivalence in a nonjudgmental and compassionate way.