Hello Angela,
in Lima you have numerous clinics and doctors that could help your son. The problem I see is getting him there. So is there no-one here in Lima being able to support and convince him seeing a doctor? No friends, colleagues, family members?
I tried to find any support groups, but wasn't really successful. Anyway I read that there is Bipolares Anonimos in Peru, but couldn't find a website. But you could try and contact Teresa under perubipolar [at] hotmail [dot] com.
Another option might be getting in contact with abint Peru. Probably they can help you and point you in the right direction.
Sorry I couldn't help more.