scmp: Mind Frame

新療程研究治創傷後遺症

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Mind Frame

Elaine Yau (elaine.yau@scmp.com)
May 15, 2012

Mental treatments involving counselling and psychotropic drugs often leave patients with expensive medical bills. In coaching sessions with psychologists, patients have to recall traumatic events that precipitate their neuroses or phobias.
For those who baulk at the bills or the soul-baring chats with psychiatrists, a new type of therapy might be able to offer some fresh hope.

Cognitive bias modification (CBM), a form of cognitive behavioural therapy (CBT), has generated much buzz recently.

In recent years, researchers have been looking into how CBM helps those with social anxiety and substance abuse problems.

Professor Samuel Ho Mun-yin, from City University's department of applied social studies, is recruiting people for a large-scale study on how CBM can help people prone to post-traumatic stress disorder (PTSD). These include children with chronic or life-threatening illnesses, people with a history of drug abuse or family violence and recovering schizophrenic patients.

"How people see and process trauma has to do with their personalities," says Ho. "Some focus on the good and develop resilience. Others fixate on the bad and keep thinking about bad experiences, which leads to PTSD. Our perception is affected by our attentional bias or automatic and unconscious bias."

Psychologist Colin MacLeod from the University of Western Australia is among the pioneers in CBM therapy. He developed the dot-probe test, where people view a computer screen on which positive (a smiling face), negative (a feral dog) or neutral (furniture) images are flashed briefly, adjacent to each other. After the images disappear, dots appear where one of the images was, and the person has to respond by pushing a button. People with anxiety consistently respond more quickly to dots that appear where the negative image was located.

Similar tests have recently been turned into smartphone apps.

It is assumed that if the viewer's attention is caught by the negative picture, he is likely to respond faster to the dot that appears in the same place because his attention is already fixed on that area of the screen.

After long sessions, psychologists can assess whether the player is predisposed to suffer social anxiety in a crowd of people, which might be the case if his attention subconsciously turns to a minority of hostile faces and ignores the pleasant faces around him.

Ho says a similar version of this dot-probe test is being developed for local patients, using Chinese words and pictures that have relevance to Hongkongers. "Both pictures and words can be used for the tests. We have compiled a list of 60 Chinese words, with positive, neutral and negative meanings. We are looking for pictures with a local context."

Ho says the exercise can be also configured to snap people's eyes away from the part of the screen that shows negative images. "Our brain is adaptable, and repeated exercises over a long period can condition it to break bad habits."

In similar exercises used by Western psychologists to treat people with anxiety, the dots always flash in locations where neutral or positive images appear.

In a study conducted by the University of Amsterdam published in Psychological Science last year, more than 200 alcoholics who were at least three weeks out of detox were recruited. Half the participants did four 15-minute CBM sessions on four consecutive days. This consisted of deliberately pushing the joystick in reaction to pictures of beer, whisky and so forth (literally and figuratively pushing the temptation away), and pulling the joystick in response to pictures of soft drinks. The control subjects had no training or sham training sessions. Researchers found that a year later, 46 per cent of CBM group had relapsed, compared to 59 per cent of the control group.

Researchers at Tel Aviv University are examining whether there's a connection between cognitive biases and PTSD in American and Israeli soldiers. Ho's study on 170 local breast cancer patients, published in Psycho-Oncology last year, showed that those with attentional bias were more likely to dwell on their traumatic cancer experience and develop PTSD.

In spite of all the buzz surrounding CBM, Wong Chee-wing, clinical psychologist and chairman of the Chinese Association of Cognitive Behaviour Therapy, has doubts about the whole idea.

"There's little evidence to show that CBM can treat anxiety," he says. "Attentional bias is just one of the myriad factors that can lead to mental disorders. Anxiety is caused by many things, like a patient's personality traits and upbringing. The whole CBM concept is based on a simple premise that patients are attracted to sad images while ignoring happy faces. The idea that you can play a phone app for two hours to get your condition treated is immature."

Wong adds that CBM is yet to be incorporated into standard treatment guidelines, such as those for Britain's National Institute for Health and Clinical Excellence. CBM is a nascent field without rigorous clinical trials, says Wong, but CBT has a wealth of research and clinical data to support its efficacy.

"Computerised CBT sessions are not games like those CBM apps. When we use CBT to treat [anxiety] patients, we train them to evaluate the probability of bad things happening. Other techniques are used to help them avoid exaggerating dangers. There is computer-assisted CBT for self-learning. But the role of therapists is not excluded - they have online chats with patients."

Even MacLeod told The Economist last year that CBM is not quite ready for general use. He said that there should be more large, long-term, randomised clinical trials to show the effects of CBM.

Clinical psychologist Michelle Chan Wing-chiu says CBM can go hand in hand with traditional treatments.

"Though CBM development is still in its infancy, research has shown a proven link between bias and anxiety. Computerised practices can train the brain to break bad habits. However, at this stage, we cannot tell how long the effects will last and whether those effects will hold under all circumstances, including stressful situations."

Ho says ordinary people who are not diagnosed with mental ailments can use it to boost their resilience.

"How we perceive or interpret things has to do with our subconscious thinking, which contains biases we are not aware of. By zooming in on the biases, CBM has the potential to boost the treatment of mental problems."