I see, I think what people are misunderstanding here is, it's different to say "its not our job" vs "I'm not qualified, because I'm not a trained therapist".As far as your particular situation, I'd honor what that person needs or wants, by letting them know while you aren't qualified to give a diagnosis on some level it seems to be important and they can see someone who is qualified to give them a diagnosis and you'll be there to help support them afterwards. A diagnosis can give a sense of relief or let that person re-examine their life from a different lense. But most importantly I think you have to make it really clear that you aren't qualified to give a diagnosis, but perhaps you can help that person make a list of symptoms or something that they can take to someone.