Dr. Denning has developed specialties in differential diagnosis, psychopharmacology, psychotherapy with seriously disturbed patients, HIV, and substance use disorders. She is one of the primary developers of Harm Reduction treatments. She has written several articles as well as a book for the general public (Over the Influence: The Harm Reduction Guide for Managing Drugs and Alcohol. Guilford Press. ) This book has recently been translated into Chinese. The 2d edition of her first book, Practicing Harm Reduction Psychotherapy was released in the Fall of 2011 (with co-author Jeannie Little).
In 2000, Dr. Denning and Ms. Little created a non-profit treatment and training program, The Harm Reduction Therapy Center (HRTC), which provides a full range of mental health services to dually diagnosed individuals. HRTC also trains hundreds of mental health and substance abuse professionals, outreach workers, homeless advocacy groups, and housing staff each year in this model throughout the United States, Canada, and Asia.
Dr. Denning has completed the Diplomate-Fellow training in Psychopharmacology and also was named to the Drug Policy Resources Directory for the Media in the area of Dual Diagnosis. She is a certified addiction specialist through the American Psychological Association’s College of Professional Psychology.