I don't buy much of this. It is a fallacy that medical diagnoses are mainly based upon physical examination. The history of the patient - what they tell you - is typically more important, and, as pointed out, sometimes is the only information used for diagnosis.
One of the best ways to confirm a diagnosis is its response to treatment. Anyone who has ever treated a bipolar, schizophrenic, or depressed patient can attest to the efficacy of medications, and to what happens when the patient stops them.
In addition, psychiatric illnesses can result as side effects of medications used to treat other conditions. Interferon can induce depression, and Parkinson's medications can cause psychosis. MRI has also showed differences between normal brains and the brains of schizophrenics.
So , with psychiatric illnesses, we have conditions which respond to specific medications, which can be induced as side effects of other medications, and which, in at least one case, have objective MRI abnormalities. Using a legal argument is like the tail wagging the dog. Saying that psychiatric conditions don't exist because someone in legal trouble can pretend to have one doesn't hold water.
Well said.
Worth repeating.
Very much so; my doctor has simply called in a prescription for a short course of antibiotics on more than one occasion after contacting his office and reporting a certain kind of sore throat. And, I never ask for antibiotics if the doctor doesn't suggest them himself.
IIRC, the maxim was history is 90 percent of the (clinical) diagnosis. That's usually true in most branches of medicine, but in those branches of medicine, you can usually order a test or tests that can confirm the diagnosis before a therapeutic trial is attempted. In Psychiatry, a therapeutic trial, regardless of hazards, is usually the only confirmation that you have the correct diagnosis.