Question: Who are the professionals who treat clinical depression?
Answer: If you have a clinical depression or feel one of your loved ones does, you should go to a professional who's trained in such treatment. And that would be a licensed mental health professional, like a psychiatrist, a doctoral level psychologist. In some states, a social worker or a nurse clinician.
And if you can't find such people, then you should go to your family practitioner and talk about the problems and let them get you specialized help.