This doesn't seem to fit well with my experience. The thing that breaks me out of ennui and encourages me to pursue some task is imagining how good I'll feel experiencing the benefits of successfully completing the task. Perhaps we are talking about two different things. My issue is how to initiate some boring task. Once I'm started, I have found it's often easy to continue. In fact, it's often hard to stop. Maybe that's what you're talking about. Dopamine isn't something to break me out of ennui. It's simulating success that does it.