Being rather modest I am not going into any details, but, I have been on sub for over a year and my answer to your question is a definite NO! Now, everyone is different, so the sub could cause this I suppose. I would ask my doctor if I were you. You may be taking some other medication that could be causing this also.
As far as sub being an opiate, yes, it is. However, I have not found that it has caused any change in behaviour, or anything else. Except, of course, I no longer live for my hydrocodone fix and feel totally normal and happy for the first time in years.
Best of luck to you, and welcome to a new life of sobriety!