"Why Depression Needs A New Definition "

"The  DSM-III,  published in 1980, was the APA’s first attempt to clarify the definitions of specific disorders by listing their symptoms; the new edition included guidelines for differentiating depression from other disorders like schizophrenia, dementia, and uncomplicated bereavement, and outlined eight symptoms of depression, included “poor appetite or significant weight loss” and “complaints or evidence of diminished ability to think or concentrate.” If an adult met four of the eight symptoms, the manual counseled, he or she would meet the criteria for clinical depression. In the  DSM-V, published in 2013, depressive disorders were finally allocated their own chapter. The diagnostic criteria were mostly unchanged, with the exception of one additional symptom: “Depressed mood most of the day, nearly every day, as indicated by either subjective report (e.g., feels sad or empty) or observation made by others (e.g., appears tearful).”...

Some scientists believe that the DSM-V definition is still too vague...  in 2010, researchers in Germany testing the validity of the  DSM-IV  definition found that the criteria captured a huge population of patients with “widely varying associations with the pattern of co-morbidity, personality traits, features of the depressive episode and demographic characteristics.” The results, they argued, “challenge our understanding of major depression as a homogeneous categorical entity.”...

Bruce Cuthbert, the director of adult translational research and treatment development at the National Institute of Mental Health (NIMH), thinks that part of the problem is that researchers have largely focused their attention on finding a one-size-fits-all treatment that doesn’t exist. “When you do a clinical trial, you’re getting a bunch of people who are ‘depressed,’ but they’re actually very different,” he said. “It’s like comparing apples, pears, and tangerines. You’re not going to see a significant effect. You’re not going to be able to say, ‘This treatment works for fruits.’” Trying to create a singular treatment for depression, Cuthbert said, is like trying to create one for cancer: too unspecific to actually be helpful...

The current definition of depression, Cuthbert explains, has largely stemmed from scientists observing patients and then developing lists of symptoms based on what they saw. “The belief was that if you described the disorder well enough, you would be able to define it,” he said. But it’s becoming increasingly clear, he said, that by relying on describing the disorder, scientists are only skimming the surface in terms of understanding it."

http://www.theatlantic.com/health/archive/2015/08/why-depression-needs-a-new-definition/399902/?utm_source=SFTwitter

Definitely! I am super excited for personalized medicine, it's going to be big in a lot of ways, but one thing it will especially do is provide diagnostic tools for people to understand what is contributing to their psychiatric health or disorder, and what might help. The field is turning toward identifying "biomarkers" instead of ofte-subjectively-described symptoms (like, this is a problem across medicine, for example with autism and adhd and heart attacks being under-observed in women). Biomarkers are things like hormone/protein levels that can be measured in a blood test.

The research I'm doing right now (or, at least, while I write this) is examining the way that two people can be exposed to the same trauma but only one will develop an anxiety disorder or PTSD - and these two people might have different levels of certain gene transcripts in their blood. So, it might be possible to screen someone who is at the hospital just after a traumatic incident to determine if their body is reacting to turn that stress into a chronic condition. It might also be possible to use these biomarkers to suggest what kind of treatment will work best - CBT, certain medications, etc...

The field is really trying to understand neurodiversity now, and facing the fact that there is almost never "a gene for X". It's now being understood as a system, and perhaps there are a finite set of states of that system that can be measured, and then targeted with therapeutics.