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Objective: To lay out the argument that exercise impacts neurobiological targets common to both mood and cognitive functioning, and thus more research should be conducted on its use as an alternative or adjunctive treatment for cognitive impairment in late-life depression (LLD). Method: This narrative review summarizes the literature on cognitive impairment in LLD, describes the structural and functional brain changes and neurochemical changes that are linked to both cognitive impairment and mood disruption, and explains how exercise targets these same neurobiological changes and can thus provide an alternative or adjunctive treatment for cognitive impairment in LLD. Results: Cognitive impairment is common in LLD and predicts recurrence of depression, poor response to antidepressant treatment, and overall disability. Traditional depression treatment with medication, psychotherapy, or both, is not effective in fully reversing cognitive impairment for most depressed older adults. Physical exercise is an ideal treatment candidate based on evidence that it 1) is an effective treatment for depression, 2) enhances cognitive functioning in normal aging and in other patient populations, and 3) targets many of the neurobiological mechanisms that underlie mood and cognitive functioning. Results of the limited existing clinical trials of exercise for cognitive impairment in depression are mixed but overall support this contention. Conclusions: Although limited, existing evidence suggests exercise may be a viable alternative or adjunctive treatment to address cognitive impairment in LLD, and thus more research in this area is warranted. Moving forward, additional research is needed in large, diverse samples to translate the growing research findings into clinical practice.

Both clinical depression and subthreshold depressive symptoms have been associated with alterations in cortical thickness. Studies have yielded conflicting results regarding whether cortical thinning or cortical thickening best characterize the depressive state. Also unclear is whether cortical thickness differences are lateralized. This study examined the relationship between depressive symptom dimensions and cortical thickness asymmetry in cingulate and orbitofrontal regions. Fifty-four community-dwelling adults between the ages of 18 and 81 years received a 3-Tesla magnetic resonance imaging scan and completed the Center for Epidemiologic Studies Depression Scale (CES-D). Cortical thickness values were extracted for the rostral anterior cingulate, caudal anterior cingulate, posterior cingulate, isthmus cingulate, and orbitofrontal cortex. An asymmetry index was calculated for each region. Data were analyzed using separate general linear models for each region, in which the CES-D somatic symptoms, negative affect, and anhedonia subscale scores predicted the asymmetry indices, controlling for age and sex. Higher scores on the anhedonia subscale were associated with right-sided asymmetry in orbitofrontal thickness, whereas higher somatic symptom subscale scores predicted greater left-sided asymmetry in posterior cingulate thickness. Follow-up analyses showed the orbitofrontal effect was specific to the medial, not the lateral, orbitofrontal cortex. These results suggest asymmetries in cortical thickness are apparent at even subthreshold levels of depressive symptoms, as all but five participants were below the CES-D cutoff for clinical depression, and that the relationship varies for different symptom dimensions of depression. Understanding brain asymmetries across the range of depressive symptom severity is important for informing targeted depression treatment.

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Background: Due to the recent COVID-19 pandemic, many clinicians have transitioned to telehealth-based cognitive assessments as a practical alternative to in-person evaluations. Meta-analysis has shown that verbally-mediated measures of cognition are the most easily adapted to telehealth administration, while measures that include visual or motor components are more variably impacted. The Oral Trail Making Test (O-TMT) is one verbal measure of executive function that removes motor and visual demands. However, there is a dearth of research related to the use of the O-TMT in cognitively impaired older adults to evaluate executive function. Therefore, this project aimed to examine the relationship between O-TMT scores with other neuropsychological measures in individuals with cognitive impairment. Method: Forty-one participants enrolled in the Emory Cognitive Empowerment Program underwent telehealth-based neuropsychological assessment that included the O-TMT. The O-TMT is comprised of two parts. Part A requires individuals to count out loud from 1 to 25 and is primarily a measure of processing speed and simple attention. Part B requires individuals to alternate saying numbers and letters (1-A, 2-B, etc.) and is a measure of mental flexibility. Time to completion as well as total errors are captured during administration. Participants also completed the Montreal Cognitive Assessment (MoCA) as a measure of global cognitive function, a measure of practical reasoning (Test of Practical Judgement), and a self-report measure of cognitive change (Everyday Cognition). Correlational analyses were completed to examine the relationship between O-TMT scores and global cognitive function, practical judgment, and subjective cognitive status. Results: The sample consisted of older adults (M age = 72.84, SD age = 8.20) who were well-educated (M years = 16.07, SD years = 2.22). O-TMT Part B Time to Completion was moderately correlated with total MoCA score (r = -0.36, p = 0.03), such that slower performance was associated with poorer overall cognitive function. The O-TMT was not significantly correlated with practical judgment or subjective cognitive status. Conclusion: Results of the current study indicate poorer performance on the O-TMT part B is associated with poorer overall cognitive function on the MoCA. Future research should examine the sensitivity and specificity of the O-TMT part B for individuals who are cognitively impaired.