Study may pave the way to new treatments for depression
A new study shows that memory training for people with depression can lead to a significant improvement in their working memory and cognitive performance. Published in the journal Psychophysiology, the research by Professor Nazanin Derakshan and Dr Max Owens, from the Department of Psychological Sciences at Birkbeck, and Dr Ernst Koster from Ghent University in Belgium, shows that memory training could be a “useful tool” to target some of the common symptoms of depression.
Depression is a common and debilitating psychiatric disorder that poses a major challenge to mental health services due to its high prevalence and recurrence rate. Symptoms of depression include attention, memory and concentration problems.
The participants in the experiment all suffered from moderate depression, and were selected based on the self-reported severity of their symptoms.
At the start of the experiment participants completed a test in which they were shown a number of objects on the screen, but told to focus on two in particular. Using electroencephalography (EEG) measurements, captured by sensors placed on participants’ scalps, the scientists measured how well the participants were filtering out the irrelevant objects on the screen. An impaired ability to filter irrelevant information is related to reduced working memory and impaired attentional control as it leads to a reduced capacity to retain relevant information. Participants were later shown another screen, which included the two objects that they had been told to pay attention to, and were asked whether the rotation of these objects had changed. Those whose EEG readings had shown that they were also paying attention to the non-relevant objects showed a lower ability to correctly say whether the two relevant objects had changed or not.
The participants were then divided into two groups – one undertook a training programme known to improve working memory and the other completed a non-training based activity. The scientists ensured that both groups of participants performed similarly on the change detection task at the start of the experiment.
Those completing the training were shown a sequence of visual and audio cues. They then had to determine whether either one or both of the cues matched those a particular number of steps back in the sequence. According to the participants’ performance, the task was adapted to require them to match pairs further back or more recently in the sequence, thus adapting for level of difficulty. Those in the non-training group completed a version of the training task that did not adapt to performance.
After two weeks, during which the first group completed the adaptive training task and the second completed the non-adaptive task, the participants’ working memories were tested again, using the same change detection test as at the start of the experiment. The group which had completed the training showed a significant improvement in their working memory and ability to filter out non-relevant information, whereas no training-related change was observed in the non-training (active control) group.
Dr Max Owens, lead author, said: “The improved performance in the change detection task by the group who completed the training is particularly important, as it shows that even though the training task was different to the task completed at testing , the benefits in ability to filter out irrelevant information and working memory transferred across to the new task. This shows that we are seeing real transferable benefits, which could impact in multiple areas of someone’s life.”
Professor Nazanin Derakhshan, co-author, said: “These results indicate that working memory training could be a useful tool in the treatment of people with attention and concentration problems linked to moderate depression. More work needs to be done to assess whether the training could ultimately have an impact on the levels of depression overall, but it seems clear that training programmes could certainly be employed to target some of the common symptoms.”