I just randomly came across this while wondering the same thing. I have been on Celexa for about six months now and I feel that same dull & numb feeling you are describing. Before Celexa I was on Effexor, and I had the desire to make things for around the house, tackle fun projects, solve problems and just all around outside fo the box thinking. Now I dont feel that at all, it takes me a week to finish something that used to take a couple of hours because I dont have the energy to think about how to accomplish it.