Project Summary/Abstract The main objective behind this supplement application is to provide career development and research training to Ms. Sofía Mildrum Chana, B.A., doctoral student in the Medical/Clinical Psychology Program at the University of Alabama at Birmingham (UAB). This supplement, in response to PA-21-071 “Research Supplements to Promote Diversity in Health-Related Research (Admin Supp)”, will extend the parent project Circadian and Sleep Mechanisms among Racial Groups for Nicotine Dependence, Craving, And Withdrawal (R01 DA046096-01A1) led by Drs. Karen Cropsey and Karen Gamble (MPIs). This administrative supplement will support Ms. Mildrum Chana’s pre-doctoral education and career development activities, with the main goal being the advancement of her skills as an independent researcher in the field of substance use and sleep research. The primary aim of the present investigation is to evaluate the relationship between individuals’ smoking status and perceived stress in a sample of smokers and non-smokers. Specifically, a moderated mediation model is proposed whereby risk for obstructive sleep apnea (OSA) functions as a mediating variable in the association between smoking status and perceived stress. Additionally, individuals’ racial identity will be examined as a moderating variable in this model. The proposed study serves as an extension of the parent grant’s main goal of expanding current knowledge regarding the associations between cigarette smoking, sleep quality, and circadian rhythms in Blacks and Whites. The proposed study will further this investigation by specifically examining the impact of OSA in relation to individuals’ perceived stress and their smoking status. While the relationship between smoking and OSA is well established, research is needed to understand how smoking and OSA affect individuals’ perceived stress, and how additional variables, such as race/ethnicity, may further impact these relationships. Through a series of experiential and educational activities, Ms. Mildrum Chana’s training as a researcher will be enriched, contributing to her development as an independent scientist. The training and career development components of this administrative supplement will provide the necessary support for her advancement, in addition to the mentoring assistance provided by Ms. Mildrum Chana’s primary mentor, Dr. Karen Cropsey, and her secondary mentors Dr. Karen Gamble and Dr. S. Justin Thomas (Co-I in the parent grant). The combination of the training and learning opportunities provided by the present administrative supplement, along with the preparation from her Medical/Clinical Psychology doctoral program, will equip Ms. Mildrum Chana with the necessary abilities to be successful in her future research pursuits.