Morningness-eveningness, use of stimulants, and minor psychiatric disorders among undergraduate students

Morningness–eveningness dimension in humans have been indicated to influence social behavior and individual health. The aim of the present study was to investigate the association of the morningness–eveningness dimension with behavioral and health aspects in a sample of undergraduate students. We assessed demographic data; the Pittsburgh Sleep Quality Index was used to evaluate sleep quality; the Morningness/Eveningness Questionnaire to determine morningness–eveningness, and the Self‐Reporting Questionnaire to assess minor psychiatric disorders. A total of 372 students (66.7% females), on average 21.6 years old, participated in this study. Among them, 92.2% did not smoke, 58.9% engaged in physical activities, and 19.7% were night‐shift workers. In regard to morningness–eveningness, 55.9% of the participants were intermediate between evening (39.5%) and morning (4.6%) types. Poor sleep quality (OR = 1.89), minor psychiatric disorders (OR = 1.92), and tobacco consumption (OR = 3.65) predominated among evening types. Evening types were predominantly males (OR = 1.72). This study suggests that evening types are more vulnerable to sleep and psychiatric disturbances, and tend to smoke more than morning types.