Positive feedback is a great motivator. I love to cook for people because the feedback is almost instantaneous (and usually good!). When I make something that knocks people’s socks off, it inspires me to come up with more exciting new recipes. Likewise, good feedback on my programs & blog posts inspires me to come up with new stuff on a more consistent basis.
If you have an ADHDer in your life, remember to give lots of feedback. I would say that positive feedback is more motivating than negative, but both are necessary. 🙂