Principal Investigator Biography: Darren R. Christensen received his PhD in psychology from the University of Canterbury, New Zealand. He has previously worked at the University of Arkansas for Medical Sciences and the University of Melbourne examining the efficacy of contingency management as a treatment for substance dependence and problem gambling. He is an associate professor in the Faculty of Health Sciences, a Board of Governors Research Chair (Tier II) at the University of Lethbridge, a senior research fellow with the Alberta Gambling Research Institute, a chartered member of the British Psychological Society Addictions section, and an associate member of the Canadian Society of Addiction Medicine. His research includes developing behavioural treatments for problem gambling, counselling for problem gambling, evaluations of the effectiveness of harm minimization measures, investigations of regular opioid antagonist dosing on gambling urge and brain function, opioid agonist replacement therapies, and electroencephalogram studies.