Young girls who are at high risk of depression might be impaired in their ability to respond to pleasure and reward, even if they haven’t had any symptoms of depression.A defining characteristic of depressive disorder is a weakened experience of pleasure. New research, published in the Archives of General Psychiatry, indicates that girls who are at an elevated risk of depression exhibit abnormal brain patterns when presented with the prospect of receiving a reward.
The study, led by Ian H. Gotlib, professor of psychology at Stanford University, sought to assess whether a diminished ability to experience pleasure is detectable before depression occurs or if it is a consequence of the disorder. The study focused on 26 girls ranging in age from 10 to 14. The girls in the high-risk group had mothers who suffered from recurrent depression, but the girls themselves hadn’t experienced any depressive symptoms. The girls in the low-risk group had no personal or family history of the disorder.
The participants were monitored through MRI scans as they completed a task that offered possibilities for reward or punishment. The task was made up of 100 six-second trials, and each contained an anticipation phase and a feedback phase, when the girls learned if they won or lost points. At the end of the task, the girls could redeem their points for prizes.
The girls in the high-risk group had diminished neural responses to the anticipation and receipt of reward in comparison to the low risk group. The results specifically indicated that the high-risk girls did not show any activation in the brain area that is involved with reinforcing past experiences to facilitate learning. However, the high-risk girls showed increased activation in this brain area when receiving punishment, suggesting that they may process the experience of loss and punishment more easily than they process the experience of pleasure.