In recent years, there has been a dramatic rise in methamphetamine use among people who use opioids. What is driving this effect? How do these drugs interact? Do they serve substitute or complementary functions? Dr. Justin Strickland summarizes the state of the science and outlines potential solutions. Dr. Strickland is a psychologist and assistant professor of Psychiatry and Behavioral Sciences at Johns Hopkins University School of Medicine. You can learn more about his work here.