Energy drinks are potent mixtures of ingredients like caffeine, guarana, sugar, ginseng, and aspartame. They are intended (and marketed) to improve mood, alertness and productivity—but may have long-term secondary effects that are decidedly less beneficial.
A variety of cross-sectional studies has already examined the relationship between energy drink consumption and mental health problems like anxiety, depression, and increased feelings of stress. Few to date, however, have done so longitudinally, meaning that causal relationships have been difficult to determine or demonstrate.
To remedy this, the present study looked at data from 897 individuals who have been followed from birth in the context of the previously published Raine study. Questionnaires were given at age 20 and again at age 22 regarding, among others, energy drink consumption and mood.
After controlling for parental mental health, illicit drug use, dietary patterns, family income, parental alcohol consumption and cigarette use, BMI, physical activity and other factors, the researchers found that changes in energy drink consumption were positively associated with increased stress scores and, in young adult males, depression and anxiety.
The authors have made valiant efforts to control for confounding variables, and propose several ways by which energy drink consumption may affect mod, including altering sleep behavior. The possibility of some upstream behavior or other element acting on energy drink consumption and depression and anxiety separately, however, is left largely unexplored.
General lack of energy, for example, can be caused by any number of external influences or internal factors, and could explain increased symptoms on the one hand and lead to increased energy drink consumption on the other to combat the underlying fatigue. The authors do note that the ingredients in energy drinks may exacerbate existing symptoms of anxiety, depression and stress.
The authors recommend that future studies will want to explore additional measurements, as self-reporting, especially of mental health issues, is subject to under- and/or over-reporting bias. Additionally, many of the participants lost to follow-up in the context of the (now 30-year-long) Raine study were characterized by socioeconomic disadvantage, meaning results may be skewed.
Despite their widespread consumption and, in many nations, limited regulation, the deleterious effects of energy drinks are not fully understood, something the present study, “Consumption of energy drinks is associated with depression, anxiety, and stress in young adult males: Evidence from a longitudinal cohort study”, seeks to remedy.