In DSM-5, there are separate proposed measures of diagnostic severity, of suicide behavior, and of disability so that it is clear what is being measured. This in turn brings more dimensionality to the manual.
For instance, rather than having clinicians use the GAF to rate severity, explicit instructions about what constitutes a mild versus a moderate versus a severe presentation are given for many disorders. It takes a lot of the guesswork out for clinicians. Being able to indicate gradients of severity within a disorder, rather than simply indicating a disorder’s presence versus its absence, moves us further away from the yes/no approach of categorized disorders and more toward a dimensional perspective that better depicts the way psychiatric illnesses actually appear in real life.
You seem to be emphasizing that DSM-5 is less about assessing fixed characteristics in people than it is about guiding clinicians to think in a certain way about the very act of categorizing itself.
Regier: We wanted to get therapists out of the mindset of having to find the exact diagnosis to fit a certain patient. That’s the problem with the old, reified categorical diagnosis. DSM-5 looks at diagnostic categories as indicating a central tendency, rather than an exact fit for all of the symptoms with which the patient may present. In other words, it encourages therapists to think about the diagnosis that best characterizes an individual in terms of the range of symptoms that they’re displaying.
It seems like you’re saying that our categories are never fully going to reflect the almost unimaginable complexity of human nature.
Regier: The best analogy I know for what we were trying to do in DSM-5 was put forth by the famous psychiatrist Emil Kraepelin toward the end of his career. Rather than a collection of separate diagnoses, he said that we need to think of a diagnostic system as being like a pipe organ, a complex instrument, comprised of different pipes with distinct registers. My wife was a church and concert organist for many years, so I’ve spent a lot of time in organ lofts pulling different stops for pieces with rapid transitions. When I first heard this analogy, it appealed to me. Thinking about various diagnoses, I thought to myself, a loud, brassy stop like the trumpet stop might represent manic symptoms. In contrast, the mournful bassoon reed stop could represent depressive symptoms. Each of these stops or registers is distinct and can be analogous to the central tendencies of diagnoses. A large organ can have hundreds of stops and thousands of pipes.
Registers of pipe can be blended together to capture the complex characteristics of multiple-symptom presentations. For some patients, where seemingly everything that could go wrong with them does go wrong, you may need to use the full organ as an analogy for the multiple symptoms they’re expressing. Think of all those organ pipes as genetic vulnerabilities all interacting with each other as the organist pulls on the other stops. I think this is a way of thinking about diagnosis that’s different than thinking only about the diagnostic system as a collection of discreet conditions.
Everyone who’s had to deal with the clinical reality of patients realizes that they don’t come in neat little packages. However, it’s still important to know that there’s a difference between bipolar disorder and schizophrenia—think of them as different registers—and there’s a difference in how you should treat them. Yet both Kraepelin and modern clinicians informed by the most current research recognize that blends such as schizoaffective disorder are common and possibly reflect shared genetic vulnerabilities.
What do you say to people who criticize the DSM as presenting itself as the bible of psychiatry?
Regier: It’s not a bible of any kind. It’s supposed to be a set of scientific hypothesis that are meant to be disproven and improved upon so we can better understand mental conditions. I know we’ve been accused of trying to overmedicalize common human experiences and make pathology out of everyday behavior, but I think there’s already enough psychopathology out there, and there are too few clinicians to adequately treat what is already present in our communities. We don’t need to invent new diagnoses to generate more business for clinicians, and in fact we’ve actually decreased the number of separate disorders in DSM-5 from the number in DSM-IV. At the end of the day, what’s most important is whether or not this edition of the DSM will really help clinicians and researchers think more clearly about mental disorders and give us a common language that can help our field continue to develop and evolve.
Darrel Regier is Vice Chair of the DSM-5 Task Force.