Dr. Lloyd Sederer, adjunct professor at Columbia University's Mailman School of Public Health and the author of The Addiction Solution: Treating Our Dependence on Opioids and Other Drugs (Scribner, 2018), looks at approaches to addiction treatment that have failed in the past and what can be done now to promote recovery. He adds that while we don't know enough about marijuana's effects, given the impetus to legalization, we should seize the opportunity to study it.