The medical model and the bio-psycho-social model are fairly different and so we're taught things differently in school, which might be why there isn't as much collaboration as there maybe should be
The medical model goes a little something like:
>something is broken
>find a way to fix that part
>part is fixed
>problem solved
Mental health considers genetics and family history, social influences and upbringing along with mental state and well-being to make a whole, and then the parts of that whole are looked at or worked on to try and improve the person overall.
It's definitely less scientific when you're talking about counseling... I've found that behavioural interventions are more structured though