In this innovative text, Dr. Denning boldly demonstrates how effective therapy can be initiated with patients still using drugs—their abstinence neither waited for nor insisted upon.  Her comprehensive rationale for the harm reduction model, and the step-by-step guidelines for assessment and treatment are so cogently laid out that they gently invite all clinicians to reexamine their beliefs about substance abuse as a disease or moral failing.  The author has effectively interwoven issues of public health, psychotherapy, motivational interviewing, and relapse prevention to address effectively the needs of mental health and drug use dual-diagnosis patients.