Quote Originally Posted by Judge Pen
I've been told, at least informally, that it's because of the difficulty to distinguish between actual illness and pre-established personality disorders. What's your perspective on that?

Well, in the strictest sense, "personality disorders" are an axis 2 diagnosis in the DSM, while disorders such as Depression and Schizophrenia fall on Axis 1. But if I understand your question correctly, you mean the difference between what a person has become through his or her environment, upbringing, choices, etc... vs. what he or she is predisposed to biologically. In the current mental health system, it is particularly difficult with adult patients to differentiate what nature gave them and what lifestyle has given (or exacerbated) due to the extremely high comorbidity of mental illness and substance abuse. It turns into a kind of chicken and egg thing, though for the purpose of acute inpatient treatment, it's a largely academic point. Treatment is the same regardless of causal factors. Ultimately, you want to refer them for further substance abuse treatment following discharge, and it will effect some of the supplemental meds you give (you don't want to throw a lot of ativan at a junkie). However, the diathesis stress model has been widely accepted for a long time, and it suggests that biology combines with life stresses to create active mental illness in many cases. Stresses can be a bad childhood, substance abuse, homelessness, any number of things.

Anyway, I think a big part of the reason why people tend to utilize the DSM in a limited fashion is because its greatest diagnostic clarity is in regards to the more commonly seen illnesses, such as Bipolar, Major Depression, Schizophrenia, and the Anxiety Disorders. A lot of the other stuff, the stuff you see greater changes in from one iteration of the DSM to the next, is maybe more to get you thinking of possibilities when you have a wtf kind of case. But this is largely conjecture on my part, just my thoughts based on my observation and experience.