Small Clinical Trial Supports Larger Scale Testing
• Science Update
A computer-based training method that teaches a person with anxiety to shift attention away from threatening images reduced symptoms of anxiety in a small clinical trial in children with the condition. The results of this first randomized clinical trial of the therapy in children with anxiety suggest that the approach warrants more extensive testing as a promising therapy.
As many as a quarter of 13- to 18-year-olds have met the criteria for an anxiety disorder at some point. Currently available treatments—including cognitive behavioral therapy and medication—relieve symptoms of anxiety in about 70 percent of children treated. Most children with clinical anxiety do not receive treatment, partly because of difficulties in access to care, including distance and financial resources. Scientists are searching for additional approaches, including therapies that do not involve medication with its associated side effects.
A treatment called attention bias modification (ABM) has emerged from the observation that people with anxiety unconsciously pay more attention than others to anything that seems threatening. One way of detecting such a bias is a dot probe test. In the test, people view a computer screen on which angry and neutral faces are flashed briefly, adjacent to each other. After the faces disappear, a test image of dots appears where either one or the other face was, and the person has to respond by pushing a button. People with anxiety consistently respond more quickly to dots that appear where the angry face was located.
ABM presents patients with an exercise similar to the dot probe test, but the dots always appear where the neutral face was, and thus consistently draw the attention of the participant to this non-threatening image. A recent meta-analyses of ABM in adults by some of the same investigators who carried out this work suggested its potential as a treatment.
Researchers at Tel Aviv University (TAU) in Israel carried out a clinical trial on ABM as an outcome of a three-year collaboration with scientists at the National Institute of Mental Health and the University of Maryland, College Park, Maryland. Yair Bar-Haim of TAU led the study, which appears in the American Journal of Psychiatry. The study enrolled 40 children, 8 to 14 years old, who had sought help for anxiety. For children receiving ABM, after faces appeared on a screen, two dots appeared on the screen; children had to determine whether the dots were side by side, or one above the other. In every case, dots appeared only where the neutral face had been. There were also two control groups: in the first, dots appeared equally frequently where angry and neutral faces appeared; in the second, the only faces that appeared throughout were neutral, so the dots always appeared in the location of a neutral face. The object of the second control group was to help confirm that any therapeutic effect was from the ABM training, and not from desensitizing the children to threatening faces. Children in the study were randomly assigned to receive treatment, or to be in one of two control groups. All children had four training sessions over 4 weeks, with 480 dot-probe trials per session.
Although the trial was small, there was a “reasonably robust” decrease in the severity of anxiety, according to the authors. Following ABM, both the number and severity of symptoms were reduced.
An important feature of ABM, says NIMH author Daniel Pine, is that it addresses the fundamental neurological function underlying anxiety: attention. Changes in attention happen very quickly—in milliseconds. “We know from neuroscience that if you want to change behaviors that happen very quickly, you have to practice. You can’t just tell someone how to drive, or throw a ball. You have to practice,” says Pine.
Longitudinal studies that follow children into adulthood suggest that most chronic mood and anxiety disorders in adults begin as high levels of anxiety in children. In fact, childhood anxiety is as important in predicting adult depression as it is for adult anxiety. The ability to influence attention biases early in development might provide a powerful means of prevention for both of these disorders later in life. The approach requires no medication and in practical terms, the computer-based nature of ABM lends itself to large-scale dissemination, in a medium children are comfortable with. Larger-scale trials will be able to provide more information on the efficacy of the treatment in children and how it works to reduce symptoms of anxiety.
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Eldar, S., Apter, A., Lotan, D., Perez-Edgar, K., Naim, R, Fox, N.A., Pine, D.S., and Bar-Haim, Y. American Journal of Psychiatry. 2012 Feb 1;169(2):213-30.