We now know it’s the result of an imbalance in the parts of the brain that are responsible for feelings of disappointment.
Deep in the brain, we have remnants of our ancient brain and one of these parts reacts to unexpected, negative events such as punishment. If you don’t get an expected reward, parts of your brain light up. This is the “disappointment circuit”.
Hyperactivity in this part of the brain is also associated with depression.
Serotonin, the brain’s natural antidepressant, is low in people with hyperactivity in the disappointment circuit. The brain doesn’t have a system to reduce this over-activity and it just runs amuck, resulting in depression.
So, before you criticize Sarah about her reactions to disappointment, know that it’s a brain thing. Help her learn to cope.