No segment of the population is immune from the effects of addiction to substances or harmful behaviors. However, some groups are especially hard-hit. During the month of January, when many communities conduct point-in-time estimates of their homeless populations, the BASIS is dedicating its attention to the experience of addiction among people who are homeless or struggling with economic hardship. The relationship between addiction and economic hardship is complicated: for some people, experiencing substance use disorders and other forms of addiction might contribute to economic hardship and homelessness; among others, the strained caused by financial and housing instability might contribute to addiction. This month, each BASIS review will focus on economic hardship and a particular expression of addiction. Earlier in the month, the STASH started the conversation by examining the social lives of homeless youth, exploring whether particular types of peers more likely than others to encourage substance use and other risky behavior. The WAGER continued the conversation with a focus on the link between gambling disorders and housing instability. Last week, The DRAM explored how drinking patterns changed in America during the Great Recession, when many people experienced significant economic hardship. This week's ASHES reviews a study of the association between homelessness and cigarette smoking. We hope that this Special Series adds to readers’ understanding of the diversity of research and scientific findings regarding this important topic.