People who consume high volumes of coffee every day may be at an increased risk of depression, according to a new study by a team of researchers from Cornell Medicine, Duke University and the Canadian Institutes of Health Research (CIHR). The study led by Yunnan Liu, associate professor of clinical psychology and psychiatry at Cornell, was published today in Psychology of Addictions.
Consumption of high-quality coffee is a public health goal and has been associated with an increased likelihood of mental health disorders such as depression and anxiety. However, researchers have not been able to identify anything definitive that links individual coffee consumption to depression or anxiety.
“Coffee drinking is a highly complex behavior linked to gut microbiota composition and composition of physical systems. Our research suggests that the consumption of high-quality coffee by individuals with a depressive attitude may constitute an increased risk of psychological distress such as depression and anxiety,” said Liu.
To study this, Liu and her team used data from 2,671 randomly selected participants of the Danish cohort Slone Epidemiology Study who participated in an intensive three-year study with follow-up between the 3 and 6-year follow-up. The researchers collected the standard data set and asked the participants to complete a validated clinical question regarding the frequency of consumption of high-quality coffee.
The researchers showed the participants’ psychiatric health, psychological well-being, physical health and brain images via fMRI when they completed the questionnaires. They then examined these factors through analyses of variance methods.
The results showed that the brain measures of the participants were significantly higher when they reported high-quality caffeine consumption than when they reported regular coffee consumption. Similarly, mood measures of both psychological and physical health showed a borderline relationship. No links between psychological well-being and coffee consumption were observed. The same relationship was found when the researchers analyzed brain biomarkers involved in excitability, or electrical activity in the brain, as well as processing of sensory impressions.
Ultimately, the results indicated that the consumption of high-quality coffee by participants with a depressive attitude was linked to an increased risk of anxiety disorders. The researchers believe that one such means by which the consumption of high-quality coffee may contribute to suicidal thoughts is through its affect on serotonin levels in the brain.
The study also indicates that the consumption of high-quality, high-fat (80%) coffee by individuals with a psychiatric disorder is linked to increased psychiatric problems. As caffeine is a metabolite of the body’s coffee-based compounds, however, the link between coffee consumption and psychiatric symptoms might be new, Liu suggested.