A new study conducted at the School of Experimental Psychology has made an important contribution to a debate in the literature regarding the role of the neurotransmitter, dopamine, in over-eating and obesity. Dopamine is known to be important for the experience of reward from food. One idea is that under-active levels of dopamine can cause people to eat too much in order to compensate for a ‘sluggish’ reward system (i.e., they eat more to get sufficient reward). The study tested this idea using a technique called acute tyrosine/phenylalanine depletion, which induces a short-term overall reduction in levels of dopamine in the brain. Seventeen male volunteers underwent this procedure. The results showed no evidence for over-eating following acute reduction of dopamine. In fact, the findings were in the opposite direction, in that participants reported lower levels of hunger when they were dopamine-depleted. These findings have implications for the development of pharmacological treatments to combat obesity. The research is published in
Physiology & Behavior.
Charlotte A. Hardman, Vanessa M.B. Herbert, Jeffrey M. Brunstrom, Marcus R. Munafò, & Peter J. Rogers. Dopamine and food reward: Effects of acute tyrosine/phenylalanine depletion on appetite. Physiology & Behavior (2012). doi:10.1016/j.physbeh.2011.12.022