Support groups like you are talking about are usually lead by peers, not professionals. Therapy groups are run by professionals such as pdocs, tdocs and social workers. That being said, I go to a support group that is facilitated by a psychiatric nurse. She does not offer medical advice and just tries to keep us on topic and pull people into the discussion. I usually like it but don't "need" it. The functioning of the group is determined by the people who attend it more so than by the person who leads it.