There are "nervous breakdowns" which only happen once. Many historical figures have had them.
But on your larger point about fuzzy diagnoses I agree with you. In my experience, diseases like schizophrenia are better understood as a large number of unique diseases under a single heading. Saying "I have schizophrenia" is like saying "I own a dog". While an accurate statement, there are many different kinds of dogs, and their behavior varies widely. Schizophrenia is the same.
If you've spent time with groups of people with schizophrenia, you'll see that there's an extremely wide range of outcomes. I think the wide range of outcomes may be explained by there being a number of different diseases.
But on your larger point about fuzzy diagnoses I agree with you. In my experience, diseases like schizophrenia are better understood as a large number of unique diseases under a single heading. Saying "I have schizophrenia" is like saying "I own a dog". While an accurate statement, there are many different kinds of dogs, and their behavior varies widely. Schizophrenia is the same.
If you've spent time with groups of people with schizophrenia, you'll see that there's an extremely wide range of outcomes. I think the wide range of outcomes may be explained by there being a number of different diseases.