I'm finally going to start a new job (I'm not hired yet though, still in multiple procedures). All jobs that I can find are for 36-40hour workweeks. I need some time of almost weekly to go to therapy. 
Here comes the question: How do I say this at my interviews without immediately disqualifying myself? 
I don't want to sign a contract for 40hrs when I know I won't be able to work that much.

Does anyone know how to deal with this?
Advice is very much appreciated.