Brain scans help predict treatment outcomes for social phobia
By Amy Karon
A new study has taken the first step in using functional magnetic resonance imaging (fMRI) to predict treatment response for social phobia, a chronic, debilitating mental illness that affects almost 7 percent of adults in the United States every year.
Based on these results, the study’s authors hope that brain scans can one day help clinicians select the best treatments for individual patients with social phobia.
The study successfully linked fMRI results to patients’ subsequent response to cognitive-behavioral therapy (CBT), a common treatment for social phobia and other anxiety disorders. Researchers enrolled 39 patients in the Boston, Mass. area who met DSM-IV criteria for social phobia and had not taken psychiatric medications for at least two weeks.
At baseline and after completing 12 sessions of CBT, patients underwent fMRI scans viewing pictures of angry and neutral faces, negative and neutral scenes, and “potent negative” scenes, such as images of sharks.
The researchers found that patients who improved the most after CBT also had the highest baseline levels of fMRI activity in the brain’s higher-order visual cortex, which processes visual information. That finding surprised them, they wrote. They instead had expected to find a link between treatment response and fMRI activity in the amygdala, or in other brain structures associated with emotions, long-term memories, and motivation.
The study’s authors did not speculate on possible reasons for these results. But Dr. Greg Siegle, an associate professor of psychiatry at the University of Pittsburgh, noted in an MIT news release that patients who improved the most from CBT might have been good at segregating visual information, such as pictures of faces. This ability could explain increased baseline fMRI activity in their higher-order visual cortexes.
The investigators next plan to test fMRI’s ability to predict response to medications and other treatments for social phobia.
About social phobia
People with social phobia fear being judged or embarrassed at work or socially. They know their fear is illogical, but cannot control it. Simply going to the store can trigger physical symptoms such as trembling, blushing, nausea, and sweating. They often harbor a profound wish to make friends and improve work relationships, but fear shackles them.
Behavioral studies indicate that patients with social phobia may particularly struggle to get better if they have severe symptoms, developed the disorder at an early age, don’t think treatment will work, have unrealistic expectations of their therapist or also have other types of anxiety disorders.
Current treatment options
Studies indicate that counseling therapies such as CBT can ease the symptoms of social phobia for some patients. In a randomized, controlled trial, about 65 percent of patients with social phobia who underwent CBT therapy improved on the Leibowitz Social Anxiety Scale, a common tool for assessing the severity of social phobia.
In another study, 42 percent of patients improved with interpersonal therapy, which focused on changing behaviors such as avoiding social situations. In contrast, only 7 percent of patients improved with no treatment.
Medications such as Paxil (paroxetine), Zoloft (sertraline), Prozac (fluoxetine), Luvox (fluvoxamine) and Effexor (venlafaxine) can also help and are often used in combination with therapy. In a 2005 study, 44 percent of patients with social phobia improved on the Leibowitz scale after taking Effexor for 12 weeks — significantly more than the 30 percent who improved on placebo.