Blunted neural response to anticipation, effort and consummation of reward and aversion in adolescents with depression symptomatology

Neural reward function has been proposed as a possible biomarker for depression. However, how the neural response to reward and aversion might differ in young adolescents with current symptoms of depression is as yet unclear. Thirty-three adolescents were recruited, 17 scoring low on the Mood and Feelings Questionnaire (low risk group) and 16 scoring high (high risk group). Our functional magnetic resonance imaging task measured; anticipation (pleasant/unpleasant cue), effort (achieve a pleasant taste or avoid an unpleasant taste) and consummation (pleasant/unpleasant tastes) in regions of interest; ventral medial prefrontal cortex, pregenual cingulate cortex, the insula and ventral striatum. We also examined whole brain group differences. In the regions of interest analysis we found reduced activity in the high risk group in the pregenual cingulate cortex during anticipation and reduced pregenual cingulate cortex and ventral medial prefrontal cortex during effort and consummation. In the whole brain analysis we also found reduced activity in the high risk group in the prefrontal cortex and the precuneus during anticipation. We found reduced activity in the hippocampus during the effort phase and in the anterior cingulate/frontal pole during consummation in the high risk group. Increased anhedonia measures correlated with decreased pregenual cingulate cortex activity during consummation in the high risk group only. Our results are the first to show that adolescents with depression symptoms have blunted neural responses during the anticipation, effort and consummation of rewarding and aversive stimuli. This study suggests that interventions in young people at risk of depression, that can reverse blunted responses, might be beneficial as preventative strategies.