Biomarkers: Can Blood & Brain Scans Help with Future Depression Treatment?

Are predictive biomarkers the wave of the future of depression treatment?

Recent research has demonstrated — in small pilot studies — that brain PET scans and, in a separate study, blood proteins, may act as important biomarkers for determining whether an antidepressant or cognitive behavioral therapy might be the best treatment for a person’s clinical depression.

Such an indicator would be a potential boon for those seeking treatment for depression. Currently, depression treatment is characterized by a trial-and-error approach, with most professionals recommending most people get both medications and psychotherapy.

These studies point to the possibility that, in the future, we may have a more reliable way of directing people to the treatment that’s going to be the most effective for them.

There’s a lot of work to be done in this area, to be sure. We’re just in the very beginnings of this kind of research — studies that will likely take at least another decade to arrive at results that help guide actual, individual depression treatment.

Susan Young, in a recent article in the MIT Technology Review, has the story:

Emory University researcher Helen Mayberg reported that a PET scan, a commonly used imaging method, can reveal whether a patient will respond better to an antidepressant or cognitive behavioral therapy.

And in May, Medscape reported that David Mischoulon of Massachusetts General Hospital presented findings that the amount of a particular protein in the blood of depression patients could indicate whether a patient would do better by adding a form of folic acid to his or her treatment.

Of course, the challenge with either of these methods — if they were confirmed and expanded upon by other researchers — is the additional effort required of the patient. PET scans and blood draws must be scheduled, and the results evaluated. These kinds of tests and their analysis require additional weeks, all the while the person continues to experience their depression.

Rather than wait with no treatment, most people are still going to be placed either on an antidepressant, or go into therapy (or, ideally, do both). Only after weeks of treatment will they get a result back letting them know if they are on the right treatment for them.

Dr. David Mischoulon reinforces a false duality behind the causes of clinical depression, however:

A key goal of such research is to distinguish between causes of depression. “The presence of certain biomarkers might give us a clue whether [a particular patient’s] depression is truly biologically driven, or whether it is depression like sadness over an event,” says Mischoulon. “If we can identify people who have these biological bases, it might suggest these patients might do better with medications, as opposed to psychotherapies or meditation.”

We can already identify one of those groups of people without such medical tests. It’s a simple question asked during the clinical interview, “Have you experienced any recent loss, accident or other life event that may have caused you to be sad or feel empty?” That question gets you a result far more quickly than a PET scan or blood test, and tells you immediately whether the individual’s depression may be event-related (e.g., a complicated grief reaction, perhaps).

But more importantly, all depression has biological underpinnings, social underpinnings, and psychological underpinnings. To try to separate these out into gross categories is to oversimplify this complex disorder.

The article ends rehashing some of the tired arguments surrounding the Diagnostic and Statistical Manual of Mental Disorders, suggesting such biomarkers might change how depression is diagnosed. Today, “[…] diagnoses are largely based on the collection of symptoms presented or described by patients.” I’m not sure how that’s wildly different than many medical diseases and the ICD-9, but apparently we’re supposed to believe there’s some sort of magical medical, laboratory test for all diseases. ((Most laboratory tests in medicine don’t necessarily diagnose disease; they provide clues to what the underlying disease may be. A fuel gauge in your car tells you you’re out of fuel; it doesn’t tell you why you are out of fuel.))

I’m optimistic about the future of biomarkers to help us better understand the best treatment strategies for a person with depression — or hopefully, with any mental disorder. But it’ll be a long time before these initial studies result in reliable and robust techniques that can be translated into everyday clinical practice.

 

Read the full article: Brain Scans and Blood Draws Provide Clues to Depression Treatment