THE RELATIONSHIP BETWEEN SMOKING BEHAVIOR AND LEVELS OF DEPRESSION AMONG UNDERGRADUATE NURSING STUDENTS Introduction: University students are at a heightened risk of using cognitive enhancers and psychoactive substances, and this risk is further exacerbated by the presence of depression, which negatively impacts academic performance and increases the likelihood of substance misuse. In Iraq, the use of cognitive enhancers and psychoactive substances has grown in the past decade due to sociopolitical factors. However, depression among tobacco users remains unrecognized and overlooked, receiving inadequate attention. Objectives: This study aims to measure the levels of depression among nursing students, examine the association between smoking behavior dependence and levels of depression, as well as to find out the relationship between levels of depression and demographic characteristics. Results: The results reveal that the majority of participants (53.9%) had a moderate level of depression (M=2.36). The highest mean level was observed in all depression scale. The study also revealed a significant relationship between age group and depression at a p-value of below 0.05. Moreover, the study also revealed a significant relationship between age and depression at a p-value of below 0.05, and between ages starts smoking. Conclusions: The level of depression the smoking student was moderate. The factors include smoking type, age at which individuals started smoking, the number of cigarettes smoked per day, and the place of smoking, it can be inferred that smoking habits and behaviors contribute significantly to the likelihood of experiencing depression. ASEAN Journal of Psychiatry, Vol. 25 (1) January, 2023; 1- .