Booming business. Clinicians need to know both sides of the ongoing debate contained in this article by Smita Das, MD, PhD, MPH, and Judith Prochaska, PhD, MPH. E-cigarettes have been endorsed by Great Britain’s health authorities for harm reduction, while the FDA is developing ways to regulate their use for safety concerns. The authors summarize data on e-cigarettes, provide recommendations and resources to learn more, and emphasize the evidence for treating tobacco (traditional cigarettes) addiction in people with mental illness. They provide a thoughtful and balanced discussion of this rapidly proliferating device. See: E-Cigarettes, Vaping, and Other Electronic Nicotine Products: Harm Reduction Pathways or New Avenues for Addiction?