Study Reveals the Damaging Effects of Depression on Memory, Mind
Dr. Bart Rypma
In research published in the Journal of Affective Disorders, scientists discovered that depressive thoughts stay with people with depressed moods longer than those without negative thoughts.
“People with depression or even healthy people with a depressed mood can be affected by depressive thoughts,” said Center for BrainHealth principal investigator Dr. Bart Rypma, Meadows Foundation Chair and associate professor in the School of Behavioral and Brain Sciences.
“We have known that negative thoughts tend to last longer for those with depression. However, this study is unique in showing that these thoughts triggered from stimuli in the environment, can persist to the point that they hinder a depressed person’s ability to keep their train of thought.”
For the study, researchers recruited 75 university undergraduate students — 30 with depressive symptoms and 45 with no symptoms. All of them responded to a sentence featuring depressive thoughts, such as “I am sad,” or “People don’t like me,” or neutral information. They were then asked to remember a string of numbers.
When responding to a sentence with negative information, individuals with a depressed mood forgot more number strings than their study counterparts. When participants with a depressed mood were given the negative thought first, they remembered 31 percent fewer number strings than people without depressed mood and those with depressed mood who were given the number string first.
“We all have a fixed amount of information we can hold in memory at one time,” said the study’s lead author, Nick Hubbard, a doctoral candidate at the Center for BrainHealth working with Rypma.
“The fact that depressive thoughts do not seem to go away once they enter memory certainly explains why depressed individuals have difficulty concentrating or remembering things in their daily lives. This preoccupation of memory by depressive thoughts might also explain why more positive thoughts are often absent in depression. There simply is not enough space for them.”
The researchers suggest that this greater dedication of memory resources to negative thoughts might be the key to understanding how depression develops and continues throughout an individual’s lifetime.
“Interventions such as mindfulness-based cognitive therapy are quite successful in empowering depressed people to recognize and better regulate the content of their thoughts,” Rypma said.
“Our goal is to continue to study how such therapeutic approaches can alter the depressed brain, and how these alterations might result in better memory and outcomes for people with depression.”
The Dianne Cash Fellowship award, the Friends of BrainHealth and the Linda and Joel Robuck Distinguished New Scientist Award provided support for the study.
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