Feature
Imagine a method to treat anxiety and other mental health disorders that was inexpensive, effective after a few short treatments, and didn't require drugs or trained mental health professionals. "It does sound like science fiction, doesn't it?" says Colin MacLeod, PhD, a psychologist at the University of Western Australia.
Yet that's the hope of experts studying cognitive bias modification (CBM), a new technique that aims to alter harmful thought patterns. The technique isn't ready for prime time yet. "This is quite a young field of science," says Emily Holmes, PhD, a clinical psychologist and cognitive neuroscientist at the University of Oxford. But she and others say the nascent field has great promise.
Holmes describes cognitive biases as "habits of thought." "Some people might have a habit of looking at a teacup and seeing it as half empty, and others see it as half full," she says. That example is what's known as an interpretation bias. The glass-half-full type has a positive interpretation bias, while the glass-half-empty type interprets the same information with a negative bias. People with anxiety are more likely to interpret ambiguous information in a negative way — ascribing disapproving or unfriendly intentions to neutral facial expressions, for instance.
Then there are attention biases — things you notice subconsciously and automatically in the world around you. One person coming into a colleague's office might immediately take in the images on a computer screen, Holmes says, while someone with a spider phobia would be instantly drawn to a web in the corner of the window. Similarly, a person with anxiety is more likely to be tuned in to any potential (or perceived) threats in his or her environment.
To date, most studies of cognitive bias have centered on attention biases in anxiety. Numerous studies have demonstrated a link between the two, MacLeod says. The classic method of ferreting out these biases is the use of computerized dot-probe tests. In these tests, probes such as slanting lines or patterns of dots are alternately flashed on the screen near to or far from emotional images (such as disgusted versus neutral faces) or words (with negative or neutral meanings). Subjects are asked to identify the probes as quickly as possible when they appear.
Individuals with anxiety are faster to spot probes that pop up in that region of the screen where negative words or images had just been, indicating that's where the subjects had focused their attention. In other words, anxious individuals are automatically drawn to negative information.
The discovery of these negative attention biases hatched a chicken-and-egg problem: Does anxiety cause a negative attention bias, or does the bias cause anxiety? "It's kind of like a feedback loop, where the fears feed into the cognitive biases and those cognitive biases may maintain or even exacerbate the fears over time," says Brad Schmidt, PhD, who directs the anxiety and behavioral health clinic at Florida State University.
Intriguingly, though, studies show that by altering the bias, one can dial emotional vulnerability up or down. Most of these studies simply use a modified version of the dot-probe test. In a 2002 study, for instance, MacLeod and colleagues used a dot-probe task to train students either to attend to or avoid negative words. Seeing the probes flash repeatedly in particular areas of the screen, the subjects learned where to focus their attention — either on or away from the negative stimuli. Later, subjects were given a stressful anagram task to complete. Immediately following the stress test, the students who were trained to focus on negative stimuli showed increased anxiety compared with the students trained to avoid them (Journal of Abnormal Psychology, Vol. 111, No. 1).
"That was the start of showing this could be useful," MacLeod says, not only as a treatment, but also as a tool to study the cognitive roots of anxiety and other mental health conditions. "We can modify one facet of attention or another specifically so we can see which have an emotional impact in the laboratory," he says.
Moving beyond anxiety
Of course, CBM also has considerable appeal as a potential therapy. Most studies so far have been small, but initial results are positive. In a 2009 study described in the Journal of Abnormal Psychology (Vol. 118, No. 1), Schmidt and colleagues tested attention bias in 36 people with social anxiety disorder. Half completed a repetitive dot-probe task designed to train attention away from images of disgusted faces. By repeatedly flashing probes in the locations where neutral faces had appeared, Schmidt reasoned, the subjects would learn to focus their attention away from the negative images. Meanwhile, participants in the control group were shown probes that replaced neutral and disgusted faces with equal frequency.
After just eight 15-minute sessions — a mere two hours of active treatment — 72 percent of patients in the treatment group no longer met diagnostic criteria for social anxiety disorder, compared with 11 percent of patients in the control group. Even more startling, the diagnostic differences were still evident at a follow-up exam four months later.
Other studies have also had positive results. A 2010 meta-analysis of 12 studies (Biological Psychiatry, Vol. 68, No. 11) concluded that attention-bias modification "shows promise" as a treatment for anxiety. "When we look at the studies collectively, we see that attentional bias modification really seems to work for anxiety disorders," says study co-author Yair Bar-Haim, PhD, a clinical psychologist and neuroscientist at Tel Aviv University.
As far as cognitive bias goes, anxiety has been studied much more thoroughly than any other condition, Bar-Haim says. Still, it's not the only condition in which such habits of thought are believed to play a role. He's currently exploring the connection between attention biases and post-traumatic stress disorder in soldiers. On the battlefield, being tuned in to threats is advantageous. "That's how you survive," he says. "But eventually, when you come back home, these biases are not adaptive." The research isn't published yet, but so far, he says, there appears to be a "rather clear link" between PTSD and negative attention bias.
Negative bias has also been implicated in depression, though the association isn't quite as clear as it is for anxiety. "It remains to be determined whether extended attentional bias training is beneficial in depression," MacLeod says. Interpretation bias (rather than attention bias) probably plays a stronger role in depression, he says. Indeed, depressed individuals are more likely to interpret ambiguous information in a negative way (Cognition and Emotion, Vol. 16, No. 3).
Compared with attention bias, interpretation bias has thus far received less research focus, he adds. Still, some early studies have indicated that depressed people may be good candidates for CBM. A small study by Holmes and her Oxford colleague Simon Blackwell, PsyD, found four of seven depressed volunteers had improvements in mood and/or mental health after one week of CBM training in their homes (Applied Cognitive Psychology, Vol. 24, No. 3).
Meanwhile, other investigators are beginning to apply CBM to problems such as addiction. Reinout Wiers, PhD, of the University of Amsterdam and colleagues developed a CBM technique that involves moving a joystick to zoom in or out to approach or avoid images on a screen. Initially he found that alcoholics zoomed toward images of alcoholic beverages faster than did people without that addiction. In four 15-minute sessions, Wiers and his team trained recovering alcoholics to "push away" the virtual images of alcohol. A year later, 46 percent of the CBM-trained group had relapsed, in contrast to 59 percent of the control subjects (Psychological Science, Vol. 22, No. 4).
No insight required
A picture is worth a thousand words, as the saying goes, and to Holmes it makes sense to tap into the visual system that humans rely on so heavily. "When we do therapy, people usually just focus on the words," she says. Yet our brains process words and images very differently. In a 2009 study, she found that healthy volunteers who created mental images of positive events felt better, while those who thought about the same events verbally actually felt worse (Journal of Abnormal Psychology, Vol. 118, No. 1). Images — such as those presented in CBM training — "can be very powerful," she says.
A definite buzz is emerging around CBM. Still, it's not yet known how CBM stacks up against current treatments or how best to deliver it as therapy. So far, most of the training programs are just modified versions of the dot-probe test — a format originally designed for assessment, not intervention. "It's almost certain that we're not training attention as effectively as we could do," MacLeod says. "A lot of the work will be refinements of the training methodology."
Another big unknown, MacLeod says, is how CBM should be integrated with existing treatments, such as cognitive-behavioral therapy (CBT), which has a wealth of data demonstrating its effectiveness. He suggests that the two approaches might be more beneficial together than either therapy is on its own. While CBT excels at teaching patients to deal with negative thoughts as they arise, CBM could target the basis of such negative thoughts earlier in the cognitive process, at a more subconscious level. "The delivery of the intervention requires nothing in the way of insight," he says.
In fact, adds Schmidt, CBM usually doesn't feel like therapy at all. In his studies of CBM, "almost no one who has been in active treatment thinks they've gotten active treatment," he says. "I don't think any patient enjoys doing cognitive behavioral therapy. They enjoy getting better but the treatment itself is hard." Targeting automatic biases instead may be a good option for patients who don't comply with CBT protocols.
CBM could also be useful for patients in underserved areas. Offering bias modification programs on the Web or even through smartphones could be inexpensive or even free, and could reach people in remote areas where mental health care is lacking, Schmidt says. Phil Enock, a doctoral candidate at Harvard University in the lab of psychologist Richard McNally, PhD, is studying attention bias modification to treat social anxiety and worry via the iPhone and Android phones.
Meanwhile, Bar-Haim is launching an international collaboration with researchers at the National Institute of Mental Health that will investigate CBM for anxiety disorders. The project will encompass randomized controlled studies at mental health treatment centers around the globe. "[CBM] sounds very promising, but we still have to do the work," he says.
No one expects CBM to replace existing treatments. But if the research pans out, mental health professionals will have good cause for celebration. As Bar-Haim says, "It's not often that a new therapy like this comes around."
Kirsten Weir is a writer in Minneapolis.
