When it comes to the ‘positive’ symptoms of schizophrenia, such as hearing voices, cognitive behavioural therapy (CBT) has mostly be used to help reduce the distress and burden that they can cause. But now Jerome Favrod and colleagues in Switzerland have tested the idea that CBT could help tackle the cognitive deficit that some argue causes the voices to be heard in the first place.
One theory for why people with schizophrenia hear voices is that they mistake their own inner thoughts, or words they are planning to say, as being of external origin. Favrod’s team recruited a 38-year-old patient who heard voices that he believed belonged to an evil spirit. They tried to help him better recognise the source of the words he heard.
During training, the researchers would pick a category such as ‘fruit’, and then show the patient a picture of one fruit, name another fruit out loud, show him the written name of another fruit and finally ask him to name a fruit. Later they presented him with a list of all the fruits mentioned, and asked him to recall which fruit he had named, and which had been shown in a picture, written or named out loud. They taught him to better remember items he had suggested by using personal memories – for example if he suggested apple, to link this with an apple tree in his grandmother’s garden.
After 6 hours of training over 11 weeks, the patient was better at recognising his own suggestions, and better at recalling the personal memories he had tied them to. Crucially, his auditory hallucinations were also improved and continued to be improved at follow-up a year later.
“Even though we report a single case study, we think that the results definitely encourage the potential use of cognitive remediation for auditory hallucinations”, the researchers concluded.
Favrod, J., Vianin, P., Pomini, V. & Mast, F.W. (2006). A first step toward cognitive remediation of voices: a case study. Cognitive Behavioural Therapy, 35, 159-163.