Depression is a syndrome of stress- and emotion-dysregulation, involving compromised structural integrity of frontal-limbic networks. Meta-analytic evidence indicates that volumetric reductions in the hippocampus, anterior cingulate cortex, prefrontal cortex, striatum, and amygdala, as well as compromised white matter integrity are frequently observed in depressed adults. Exercise has shown promise as an effective treatment for depression, but few studies have attempted to characterize or identify the neural mechanisms of these effects. In this review, we examined the overlap between structural brain abnormalities in depression and the effects of exercise on brain structure in adults, to highlight possible neural mechanisms that may mediate the positive effects of exercise on depressive symptoms. The prefrontal cortex, anterior cingulate cortex, hippocampus, and corpus callosum emerged as structural neural markers that may serve as targets for exercise-based treatments for depression. These findings highlight the need for randomized exercise interventions to test these proposed neurobiological mechanisms of exercise on depression.
Objective Executive deficits may play an important role in late-life suicide. Yet, current evidence in this area is inconclusive and does not indicate whether these deficits are broadly associated with suicidal ideation or specific to suicidal behavior. This study examined global cognition and specifically executive function impairments as correlates of suicidal ideation and suicidal behavior in depressed older adults, with the goal of extending an earlier preliminary study. Design Case-control study. Setting University-affiliated psychiatric hospital. Participants All were aged 60+: 83 depressed suicide attempters, 43 depressed individuals having suicidal ideation with a specific plan, 54 non-suicidal depressed participants, and 48 older adults with no history of psychiatric disorders. Measurements Global cognitive function - Dementia Rating Scale (DRS), Executive function - Executive Interview (EXIT). Results Both suicide attempters and suicide ideators performed worse than the two comparison groups on the EXIT, with no difference between suicide attempters and suicide ideators. On the DRS total score, as well as on Memory and Attention subscales, suicide attempters and ideators and non-suicidal depressed subjects performed similarly and were impaired relative to with non-psychiatric control subjects. Controlling for education, substance use disorders, and medication exposure did not affect group differences in performance on either the EXIT or DRS. Conclusions Executive deficits, captured with a brief instrument, are associated broadly with suicidal ideation in older depressed adults but do not appear to directly facilitate suicidal behavior. Our data are consistent with the idea that different vulnerabilities may operate at different stages in the suicidal process.
Objective Cognitive impairment has been associated with late-life suicidal behavior. Without longitudinal data it is unclear whether these are transient features of a depressive state or stable impairments. We examined longitudinally the course of cognitive impairment in older adults with depression and a history of suicide attempt. Methods We investigated the persistence of cognitive impairment over time in 198 depressed older adults (age >60); 91 suicide attempters, 39 depressed individuals with suicidal ideation (ideators), and 68 non-suicidal depressed adults assessed over a 2-year period at four time points. We used linear mixed effects modeling to examine group differences in trajectories of cognitive decline over 2 years, using the Mini-Mental State Exam (MMSE), Mattis Dementia Rating Scale (DRS), and Executive Interview (EXIT). Results Over the 2-year period, suicide attempters performed significantly worse than both suicide ideators and nonsuicidal depressed older adults on the MMSE (mean difference: from ideators: −0.88, p = 0.02; from nonsuicidal depressed: −1.52, p < 0.01), while on the EXIT and DRS, suicide attempters performed significantly worse than non-suicidal depressed older adults (mean difference: in EXIT: −1.75, p=0.01; in DRS: 3.04, p < 0.01; in MMSE: 1.15, p < 0.01). Cognitive impairment in suicide attempters partly resolved, as indicated by a group*time interaction on the DRS (p= 0.039), but not the EXIT (p= 0.58) or the MMSE (p= 0.08). Conclusions Cognitive impairment in late-life suicidal behavior appears to involve both a stable and a state-related component.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.