1. Trajectories of Hyperactivity and Inattention Symptom Scores in Boys of Low Socioeconomic Status: An Assessment of Risk Factors and Cigarette Smoking Behaviors in Late Adolescence and Young Adulthood Cheng, Wendy Yin Kei 2019 Theses EpidemiologyAttention-deficit hyperactivity disorderSmoking--Psychological aspectsPoor childrenAttention-deficit hyperactivity disorder--Psychological aspectsRisk-taking (Psychology)