Is Paranoia a symptom?

My partner was diagnosis with ADHD.  The Dr has said he is off the charts and we are working to get him meds. My question is "is paranoia a symptom?" He has this feeling that I am cheating on him? We have been a relationship for over 4 years and he has NO reason to even feel this way?  It's almost crazy talk, he picks out little details about stuff and makes them into me cheating on him?  Like when I have to work late?  or if I don't pick up my cell phone during my lunch break?  There are even times were he has said some things that are very demeaning about me or to me? like items I am wearing to work or my undergarments?  I am not sure how this fits in to the ADHD diagnosis - does it?