Depression and Short-Term Memory
Millions of people worldwide suffer from depressive mood. By conservative estimates, depression costs the U.S. government about $83 billion each year. Research has consistently shown that depression, cognitive impairment and dementia are all common in older adults. As standards of living improve around the world, people are living longer. In the U.S., the population 65 and over increased 15% between 2000 and 2010 and is expected to increase an additional 36% by 2020, reaching 55 million. These projections have created a surge in research on aging and related issues, such as depression, cognitive impairment and dementia.
While a slight decline in cognitive functioning is considered a part of normal aging, cognitive impairment and depression are not. Additionally, studies have suggested that depression is associated with an increased risk of dementia. A new study conducted by researchers at the Center for BrainHealth at The University of Texas in Dallas has found a link between cognitive impairment and depression, suggesting that depression can trigger short-term memory loss. It is the first such research demonstrating memory loss in people suffering from depression that was conducted in a laboratory setting.
The researchers found that the presence of depressive thoughts made it difficult for participants to remember, which subsequently led to memory loss. The subjects were 157 undergraduate students, 60 of whom were categorized with depressed mood, while the rest were categorized as with non-depressed mood. All were asked to answer "True" or "False" to questions that assessed whether their thoughts were depressive or neutral thoughts. After completing the questions, participants were asked to memorize a series of numbers.
The results indicated that participants with depressive mood forgot more numbers than those who were not depressed. Furthermore, people forgot more numbers after answering a question associated with depressed thought than after answering a question with a neutral thought.
The researchers called depression "an interference phenomenon" that can result in short-term memory loss by as much as 12 percent. They also suggested that their research may help to explain why people who suffer from depression find it difficult to concentrate, have poor work performance, and often experience a decline in personal and social relationships.
The study has the potential to assist scientists in developing new therapeutic approaches in the treatment of depression, such as teaching a person to recognize and inhibit depressive thoughts. This type of psychoeducation typically involves teaching a person about how to recognize signs of relapse so they can get necessary treatment before the depression worsens or occurs again.
Hubbarda, NA, Hutchisonab, JL, Turnera, M, Montroyc, J, Bowlesc RP, and Rypmaab, V. (2015). Depressive thoughts limit working memory capacity in dysphoria. Journal of Cognition & Emotion: DOI: 10.1080/02699931.2014.991694