Differential associations between types of verbal memory and prefrontal brain structure in healthy aging and late life depression

Abstract

Verbal memory deficits attributed to late life depression (LLD) may result from executive dysfunction that is more detrimental to list-learning than story-based recall when compared to healthy aging. Despite these behavioral dissociations, little work has been done investigating related neuroanatomical dissociations across types of verbal memory performance in LLD. We compared list-learning to story-based memory performance in 24 non-demented individuals with LLD (age~66.1±7.8) and 41 non-demented/non-depressed healthy controls (HC; age~67.6±5.3). We correlated significant results of between-group analyses across memory performance variables with brain volumes of frontal, temporal and parietal regions known to be involved with verbal learning and memory. When compared to the HC group, the LLD group showed significantly lower verbal memory performance for spontaneous recall after repeated exposure and after a long-delay but only for the list-learning task; groups did not differ on story-based memory performance. Despite equivalent brain volumes across regions, only the LLD group showed brain associations with verbal memory performance and only for the list-learning task. Specifically, frontal volumes important for subjective organization and response monitoring correlated with list-learning performance in the LLD group. This study is the first to demonstrate neuroanatomical dissociations across types of verbal memory performance in individuals with LLD. Results provide structural evidence for the behavioral dissociations between list-learning and story-based recall in LLD when compared to healthy aging. More specifically, it points toward a network of predominantly anterior brain regions that may underlie the executive contribution to list-learning in older adults with depression.

Depression and Memory Decline in the Elderly

“…Depression had no effect on the performance of tests in which the memory accessed involved verbal narratives or visual stimuli. As other studies have reported contradictory fi ndings (Elderkin- Thompson et al, 2003;Lamar et al, 2012;Nebes et al, 2000), this issue should be further investigated in future studies.…”

“…In this study, individuals with symptoms of depression, when compared with subjects without these symptoms, performed worse on the list of words, but not on narrative recall. One study has already demonstrated that individuals with depression, compared with subjects without depression, demonstrate greater verbal memory defi cits when the verbal stimuli were presented in the form of word lists; the same result was not observed when verbal stimuli were presented in narrative form, suggesting that this difference might be due to the involvement of different neural areas for the two types of presentation of verbal stimuli (Lamar et al, 2012).…”

“…However, poorer working memory performances (Lamar et al, 2012;Nitschke et al, 2004;Pelosi et al, 2000) and impairment of immediate (Nebes et al, 2000), delayed logical memory (Elderkin-Thompson, Mintz, Haroon, Lavretsky, & Kumar, 2007), and immediate visual memory (Nebes et al, 2000) have also been observed in elderly individuals with depression.…”

“…Depressed patients differ from healthy subjects on verbal learning tasks, in which information is presented as a list of words (Lamar et al, 2012) and information recall is poorer in verbal learning (Fossati, Coyette, Ergis, & Allilaire, 2002;Lamar et al, 2012;Nebes et al, 2000), reading, verbal, and non-verbal memory (Elderkin- Thompson et al, 2003;Rozenthal, Laks, & Engelhardt, 2004).…”

Cognitive Effects of Late Life Depression: Review of Neuropsychological Findings

“…It has been reported specific effects on verbal memory in late life depression, where recalling list learning items is affected while recalling storytelling is unaffected [65]. Lamar et al [65] compared brain area volumes in late life depression with matched healthy controls, and found a correlation between volume sizes of prefrontal and cingulate sub-regions with poor performance on the list-learning task (California Verbal Learning test, CVLT) in the late life depression group.…”