Sounds like something like this:
http://www2.nami.org/Content/Navigat...d_Supports.htm
I say go for it. I can understand the feeling of "I might somehow make him worse," as that's a normal one for anyone who is caring and empathetic to feel. However, if we step back and examine the basis of that feeling, we can see that there's evidence that the fear is unfounded. You stated that it's an excellent psychologist who suggested this to you, so it can be assumed that they have thoughtfully considered options and concluded w/ excellent clinical knowledge that you specifically would do well in the role.
Also, no one person has such great power or influence over another that anything said would directly and wholly result in this other person decompensating. Let's take the worst case scenario and say this person were to coincidentally require more intensive help after speaking w/ you. That scenario is the result of brain chemistry and a whole array of factors all going on at once, including that person's own individual choices (in as much as they have the capacity to reasonably make them). It's far more likely that the same result would have happened regardless of whether you ever spoke w/ them or not.
Since the presenting issue is that the guy refuses meds and is in outpatient treatment, AND the psychologist thinks speaking w/ you might help, I'm going to guess this is someone who is in denial and struggling w/ their diagnosis (or diagnoses) and could really use another person who has been through it to help them feel less ashamed and stigmatized. This is even more likely the case since it involves a male, since socially it's arguably more unacceptable for a guy to have a mental illness diagnosis ("he's not depressed, he just needs to suck it up and quit being a p***!"). Also, they likely have inaccurate perceptions of psych drugs and/or they have had a negative experience w/ medication in the past and are very reluctant to trust a doctor again. I think you can help show this person that it's possible for them to get different results and that the possibility alone makes continuing to try worth it.
The fact that this arrangement would also benefit you financially and possibly socially makes this seem like something that is +EV for you to try. If you find it to be an enjoyable experience, not only will you have helped support someone in need, but you can continue on and possibly even build a career out of it. Best of luck!
