Bummed out by ongoing work stress? Tempted to reach for yet another cup of coffee to help you cope? Don’t—unless you want to darken your already gray mood to pitch-black as troublesome stuff heads your way. That’s the startling conclusion of a novel study on how our popular “drug of choice”—caffeine—affects us amid the challenges of chronic stress. The new research will be released today at the American Psychosomatic Society meeting in Vancouver.
The researchers asked 126 study participants to take either a caffeine pill (equal to about 2 to 3 cups of coffee) or a placebo pill with no caffeine. After a 30-minute wait, the time it takes for caffeine to be absorbed in the bloodstream, everyone looked at a series of photos designed to elicit positive or negative emotions. The positive ones showed scenes like laughing babies and an older affectionate couple; a graphic view of thumb surgery and police in protective gear at a riot were examples from the negative photos. Everyone rated each photo for how much it evoked a positive or negative reaction using a scale of 1 to 9.
One week later, participants returned to take pills again, but those who got caffeine the first time were given placebos on the second visit, while the earlier placebo-takers got real caffeine on their next visit. Then they all filled out questionnaires about how much chronic stress they faced and its causes. Again, after a 30-minute break, they viewed the photos.
When people had caffeine on board, the more chronic stress they faced, the more negative emotion they experienced in response to both the negative and the positive photos. “Caffeine seems to create a negatively biased lens that they’re seeing the world through,” says study author Lydia Roos, MA, a PhD candidate in Health Psychology at University of North Carolina at Charlotte, who worked with Jeanette M. Bennett, PhD, Associate Professor.
A deeper look at the results showed that work stress—too many demands at work—drove the chronic stress. “Caffeine is like a double whammy if you’re already overextended at work,” says Bennett. “Stress influences our perceptions. It can focus our attention on the negative. Caffeine appears to increase that and leads us to react with more negative emotions.” That may be because chronic stress activates the amygdala, a structure in the brain that warns us a threat is looming. Caffeine also revs up the amygdala, so perhaps it is amplifying the sense of threat and dialing our emotions even further over to the negative side, suggests Roos.
So, is the solution to stop drinking coffee? Not necessarily. “Most of us use it, and when we’re stressed we often drink more, but awareness of this is key,” Bennett points out. If you’re in a stressful work environment, try to limit the caffeine, Roos advises, because the unintended consequences of too much are likely to make you even more upset. If you work at a mellow yoga studio, on the other hand, an extra cup in the morning may have no ill effects at all on your mood.
The American Psychosomatic Society (APS) (www.psychosomatic.org), founded in 1943, is an international multidisciplinary academic society that organizes an annual scientific meeting and educational programs. Psychosomatic Medicine is its scientific journal. The membership of over 700 is composed of academic scientists and clinicians in medicine, psychiatry, epidemiology, health psychology and allied health services. The mission of the APS is “to advance and integrate the scientific study of biological, psychological, behavioral and social factors in health and disease.”