Improving Anxiety Treatment Helped with the Use of Brain Imaging

Research studies can provide information about how groups of patients tend to respond to treatments, but inescapably, differences among groups of patients with the same diagnosis mean that findings about groups of patients may not apply to individuals from those groups. Personalized medicine is the effort to correlate specific treatments to specific patients based on genetic information or other biologic markers.

In a study published in the journal Biological Psychiatry on May 1, 2008, researchers reported their findings on the potential use of functional magnetic resonance imaging (fMRI) to match treatments for patients with generalized anxiety disorder (GAD).

Whalen and colleagues recruited individuals diagnosed with GAD who underwent brain scans both before and after treatment with venlafaxine, an antidepressant that has been demonstrated to be effective in treating anxiety. During the fMRI scans, the participants' responses to viewing pictures of fearful facial expressions were assessed. Dr. Paul Whalen, from Harvard University (Cambridge, MA, USA), corresponding author for this article, explained, "We focused our study on a regulatory circuit in the brain involving the amygdala, an area that serves to detect the presence of threatening information, and the prefrontal cortex, an area that functions to control these threat responses when they are exaggerated or unnecessary.”

The researchers discovered that approximately two-thirds of the patients experienced relief from their anxiety symptoms after treatment, and of those who improved, some responded better than others. As hypothesized, the fMRI data predicted who would do well on the drug and who would not. According to Dr. Whalen, "subjects who showed high prefrontal cortex activation together with low amygdala activation in response to the fearful faces reported a significant decrease in their anxiety symptoms, while those showing the reverse brain activation pattern [i.e., high amygdala, low prefrontal] did not.”

John H. Krystal, M.D., editor of Biological Psychiatry and affiliated with Yale University School of Medicine (New Haven, CT, USA), commented on this study, "There is a tremendous need for biomarkers of treatment response. The paper by Whalen et al joins a small group of preliminary studies suggesting that fMRI research might contribute to the effort to develop treatment biomarkers.” He cautioned, however, "while these are exciting data, we have yet to see this type of biomarker receive sufficient rigorous validation to be useful for matching patients to existing treatments or to test new potential treatment mechanisms.”

Dr. Whalen acknowledged the early nature of their findings, noting that "future studies will be needed to determine the exact impact that brain imaging might have in helping physicians prescribe anti-anxiety medications,” but he concluded that "while a brain scan would be a relatively expensive addition to the prescribing procedure, this cost pales in comparison to the amount of time, money and angst invested by patients who go through multiple medications and dosages looking for relief.”


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