Should excessive and problematic engagement in nonsubstance use behaviors be mental disorders? The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) repositioned gambling disorder in the substance use disorders section and introduced Internet gaming disorder in the research appendix; the International Classification of Diseases (ICD-11) is also considering it. This article outlines pros and cons of considering behavioral addictions as mental disorders and also reviews the DSM-5 decision-making processes. It focuses on three conditions: gambling disorder, Internet gaming disorder (IGD), and Internet addiction (IA). We detail assessment methods and prevalence rates for these conditions and outline psychiatric comorbidities, demographic and biological risk factors, and promising treatment approaches. We also briefly discuss other putative behavioral addictions: eating/food, sex, exercise, shopping, and tanning “addictions.” Overall, data are inconclusive, and consistent terminology and methodology are needed to define and evaluate these conditions more fully prior to considering them mental disorders.