Reinforcement sensitivity is an important behavioural process that allows us to learn from our environment through either positive/rewarding or negative feedback. When we get together with friends or go for a run, chemicals in our brains send us signals that in turn make us feel good about what we’re doing. We know that depressed patients commonly report “emotional blunting” after longer use of antidepressants, in which they experience a dulling of both positive and negative emotions. But it can be difficult to tell if these symptoms are due to the depression itself or the drug treatment.
Using healthy volunteers, our new study is the first to show that chronic use of antidepressants does decrease sensitivity to positive reward as well as negative feedback, and this finding may explain the dulling feeling experienced by some depressed patients.
