Thanks for your reply. Please allow to to clarify. I am a MD specialist (not psychiatrist) in a large 1,000 bed university hospital. Every noon for the past 30 years, I have coffee after lunch in the doctor's lounge and chat with my colleagues which usually includes psychiatrists, neurologists and neurosurgeons. Sometimes we chat about psychiatry /psychiatric cases, which I find very interesting. The kind of question I asked in this form would have been discussed in an agreeable, calm, cordial and of a high academic level because all participants have academic positions and quite a list of publications. They would have understood my emphasis on heterogeneity, and would have attempted to answer my question in a cordial fashion, with no political or emotional subtext, with an emphasis on what is not yet understood. I would also add that I have quite a large library of psychiatric texts and follow the literature from a distance, just out of personal interest. Out of curiosity, I tried asking a question on this forum to see if it was possible to have interesting discussion in the Reddit psychiatry forum, and the answer is a definite no as far as I am concerned. Fine. No problem. Political correctness, emotionally charged replies, testimonials, belief systems, and let's not forget insults ('I need a barf bag'). People get upset when someone asks a question? ** Lord have mercy. To each his own. Enjoy the forum. Before saying good-bye to the forum, here is the basis for my question. A few years ago, I gave a talk on imaging at the European psychiatric meeting in Munich. Just 'for fun', I attended a talk on a topic completely out of my zone of interest: 'delusional parasitic neurodermatosis' (patient is constantly scratching his skin with consequent skin rash due to the delusion of thinking that he has a parasitic infection- obviously in Americans with no history or evidence of exposure to parasites - there had obviously been worked up by infectious disease), and incredibly, it opened my eyes, and changed the way I perceive mental illness. In a nutshell, the author used the opportunity to study an uncommon narrowly defined psychiatric condition, to show that even in the case of a rare well defined condition, the population of patients is very heterogeneous: psychotic, neurotic, pure isolated delusions and also some who were classified as having severe social problems which the author referred to as severe social isolation. Now, when I look at psychiatric conditions, I first think heterogeneity. Just for fun, I went visited a casino a few times, and with open eyes, I see heterogeneity: the heaver drinker high roller is different from the little old lady at the slot machines. Last but not least: years ago, Feynman, the quantum physicist who won the Nobel prize, said something that stuck in my mind for the rest of my life and may also benefit forum members: calling a bird by another name (ie changing the label, the terminology) does **in itself not provide any additional information about the object or concept in question. Thanks again for your post and your time, and adios psychiatry forum.