Caffeine is the most widely-used psychoactive substance in the world. The present study investigates the relationship between caffeine intake and suicide risk according to gender.
Analysis of the Kangbuk Samsung Cohort Study (KSCS) data from 80,173 individuals was performed using Chi-square tests and t-tests to determine the relationships between psychosocial constructs and gender. The relationship between caffeine intake and suicidal ideation was analyzed by obtaining odds ratios with multivariate logistic regression in which depression and sleep problems were adjusted for age.
In both men and women with suicidal ideation, the proportion of those who consume four or more cups of coffee per day was highest among the groups of various coffee intake levels. The results on the relationship between daily coffee intake and suicidal ideation revealed that suicide risk was high in both men and women who consume four or more cups of coffee a day. However, once the age, depression and sleep problems were adjusted for, suicide risk decreased in women of 1-4 cups of coffee intake per day, whereas no change was observed in men.
Regardless of psychiatric problems such as depression or sleep problems, regular and moderate caffeine intake likely reduces suicide risk as well as depression in women.