A new study published by the Center for BrainHealth at the University of Texas has specified that depressed thoughts may damage memory. The research participants consisted of 75 students, thirty classified as having depressive symptoms and 45 categorized as not exhibiting depressive symptoms. All participants were asked to respond to a sentence featuring depressive thoughts, such as “I am sad” or “people don’t like me” or neutral information. They were asked to remover a string of numbers.
“People with depression or even healthy people with a depressed mood can be affected by depressive thoughts,” explained Center for BrainHealth principal investigator Bart Rypma, Ph.D., who also holds the Meadows Foundation Chair at UT Dallas. “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.”
The research findings indicate that individuals with depressed mood forgot more number strings than people without depressed mood when responding to a sentence with negative information. People with depressed mood who were given the depressive thought first, remembered 31% fewer number strings, compared to people without depressed mood, and people 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,” explained the study’s lead author, Nick Hubbard, a doctoral candidate at the Center for BrainHealth working with Dr. 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.”
“Interventions such as mindfulness-based cognitive therapy are quite successful in empowering depressed people to recognize and better regulate the content of their thoughts,” said Dr. Rypma. “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 persons with depression.”
Nicholas A. Hubbard, Joanna L. Hutchison, D. Zachary Hambrick, Bart Rypma. The enduring effects of depressive thoughts on working memory. Journal of Affective Disorders, 2016; 190: 208 DOI: 10.1016/j.jad.2015.06.056