Executive dysfunction and the course of geriatric depression

Trail making test - black & white (TMT B&W): Normative study for the Chilean population

The trailmaking test (TMT) has an educational bias that makes it inapplicable to people with low levels of education due to its dependence on the alphabet. The TMT standardization is the only one available in Chile, and there is a need for alternative ways of using the TMT that do not depend on the level of education for its applicability. To determine the normative scores of the TMT - black & white (TMT B&W), considering sociodemographic factors in adult and elderly Chilean population. A total sample of 227 participants (133 healthy, 94 cognitively impaired) from the Ageing Mets cohort were recruited from three areas in Chile (Antofagasta, Santiago, and Puerto Montt). The TMT B&W was administered to all participants. A multiple regression model was used to generate normative data only in the cognitively healthy group, considering the effect of age, education and sex. A significant effect of age was found in the score of the TMT B&W Parts A and B. The level of education influenced the part B of the test; however, the completion rate of the TMT B&W parts A and B was over 90% in cognitively healthy people. Norms for the number of errors were obtained, and differences between groups were found after controlling for the effect of age and education. This study is the first to provide normative data for the Chilean version of the TMT B&W and will benefit clinical neuropsychologists by improving the procedures for more accurately assessing executive functions and its impairments.

Predictors of remission after repetitive transcranial magnetic stimulation for the treatment of late-life depression

Repetitive transcranial magnetic stimulation (rTMS) is an effective treatment in patients with depression, yet treatment response remains variable. While previous work has identified predictors of remission in younger adults, relatively little data exists in late-life depression (LLD). To address this gap, data from 164 participants with LLD from a randomized non-inferiority treatment trial comparing standard bilateral rTMS to bilateral theta burst stimulation (TBS) (ClinicalTrials.gov identifier: NCT02998580) were analyzed using binary logistic regression and conditional inference tree (CIT) modeling. Lower baseline depression symptom severity, fewer prior antidepressant treatment failures, and higher global cognition predicted remission following rTMS treatment. The CIT predicted a higher likelihood of achieving remission for patients with a total score of 19 or lower on the Montgomery-Åsberg Depression Rating Scale, 1 or fewer prior antidepressant treatment failures, and a total score of 23 or higher on the Montreal Cognitive Assessment. Our results indicate that older adults with lower severity of depression, fewer antidepressant treatment failures, and higher global cognition benefit more from current forms of rTMS. The results suggest that there is potentially higher value in using rTMS earlier in the treatment pathway for depression in older adults.

Influences of resting-state intrinsic functional brain connectivity on the antidepressant treatment response in late-life depression

BACKGROUND

Late-life depression (LLD) is characterized by differences in resting state functional connectivity within and between intrinsic functional networks. This study examined whether clinical improvement to antidepressant medications is associated with pre-randomization functional connectivity in intrinsic brain networks.

METHODS

Participants were 95 elders aged 60 years or older with major depressive disorder. After clinical assessments and baseline MRI, participants were randomized to escitalopram or placebo with a two-to-one allocation for 8 weeks. Non-remitting participants subsequently entered an 8-week trial of open-label bupropion. The main clinical outcome was depression severity measured by MADRS. Resting state functional connectivity was measured between a priori key seeds in the default mode (DMN), cognitive control, and limbic networks.

RESULTS

In primary analyses of blinded data, lower post-treatment MADRS score was associated with higher resting connectivity between: (a) posterior cingulate cortex (PCC) and left medial prefrontal cortex; (b) PCC and subgenual anterior cingulate cortex (ACC); (c) right medial PFC and subgenual ACC; (d) right orbitofrontal cortex and left hippocampus. Lower post-treatment MADRS was further associated with lower connectivity between: (e) the right orbitofrontal cortex and left amygdala; and (f) left dorsolateral PFC and left dorsal ACC. Secondary analyses associated mood improvement on escitalopram with anterior DMN hub connectivity. Exploratory analyses of the bupropion open-label trial associated improvement with subgenual ACC, frontal, and amygdala connectivity.

CONCLUSIONS

Response to antidepressants in LLD is related to connectivity in the DMN, cognitive control and limbic networks. Future work should focus on clinical markers of network connectivity informing prognosis.

REGISTRATION

ClinicalTrials.gov NCT02332291.

The role of semantic assessment in the differential diagnosis between late-life depression and Alzheimer's disease or amnestic mild cognitive impairment: systematic review and meta-analysis

OBJECT

The cognitive complaints encountered in late-life depression (LLD) make it difficult to distinguish from amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD) based on an analysis of neurocognitive disorders. The hypothesis of the early impairment of semantic memory in AD and aMCI is considered a potential differential cognitive clue, but the absence of this impairment has not yet been confirmed in  LLD.

METHOD

Based on the PRISMA method, we systematically seek neuropsychological assessments of individuals with LLD, the present study included 31 studies representing 3291 controls and 2820 people with LLD. Wherever possible, studies that tested simultaneously groups with LLD, AD (or aMCI) were also included. The results of the group of neuropsychological tasks relying on semantic memory were analyzed in two groups of tasks with high- or low-executive demand. The mean average effect of LLD was calculated and compared to the incremental effect of aMCI or AD on the scores. Linear regressions including education, age, and severity and type of depression were run to seek their power of prediction for the mean average effects.

RESULTS

LLD has a medium effect on scores at semantic and phonemic fluency and naming and a small average effect on the low-executive demand tasks. Differences in education is a predictor of the effect of LLD on phonemic fluency and naming but not on semantic fluency or on low-executive demand tasks. Except for semantic fluency, aMCI did not demonstrate an incremental effect on the scores compared to LLD, while AD did, for all the tasks except phonemic fluency.

CONCLUSION

Assessment of semantic memory can be a discriminating clue for the distinction between depression and Alzheimer's disease but some methodological variables are highly influential to the scores, especially education. However, high-executive semantic tasks alone do not allow us to clearly distinguish LLD from AD or aMCI, as both pathologies seem to have a largely dialectical influential relationship, but low-executive semantic tasks appear as more sensible to this pathological distinction.

Biological factors influencing depression in later life: role of aging processes and treatment implications

Late-life depression occurring in older adults is common, recurrent, and malignant. It is characterized by affective symptoms, but also cognitive decline, medical comorbidity, and physical disability. This behavioral and cognitive presentation results from altered function of discrete functional brain networks and circuits. A wide range of factors across the lifespan contributes to fragility and vulnerability of those networks to dysfunction. In many cases, these factors occur earlier in life and contribute to adolescent or earlier adulthood depressive episodes, where the onset was related to adverse childhood events, maladaptive personality traits, reproductive events, or other factors. Other individuals exhibit a later-life onset characterized by medical comorbidity, pro-inflammatory processes, cerebrovascular disease, or developing neurodegenerative processes. These later-life processes may not only lead to vulnerability to the affective symptoms, but also contribute to the comorbid cognitive and physical symptoms. Importantly, repeated depressive episodes themselves may accelerate the aging process by shifting allostatic processes to dysfunctional states and increasing allostatic load through the hypothalamic-pituitary-adrenal axis and inflammatory processes. Over time, this may accelerate the path of biological aging, leading to greater brain atrophy, cognitive decline, and the development of physical decline and frailty. It is unclear whether successful treatment of depression and avoidance of recurrent episodes would shift biological aging processes back towards a more normative trajectory. However, current antidepressant treatments exhibit good efficacy for older adults, including pharmacotherapy, neuromodulation, and psychotherapy, with recent work in these areas providing new guidance on optimal treatment approaches. Moreover, there is a host of nonpharmacological treatment approaches being examined that take advantage of resiliency factors and decrease vulnerability to depression. Thus, while late-life depression is a recurrent yet highly heterogeneous disorder, better phenotypic characterization provides opportunities to better utilize a range of nonspecific and targeted interventions that can promote recovery, resilience, and maintenance of remission.

A pilot randomized sham controlled trial of bilateral iTBS for depression and executive function in older adults

INTRODUCTION

Executive function deficits (EFD) in late life depression (LLD) are associated with poor outcomes. Dysfunction of the cognitive control network (CCN) has been posited in the pathophysiology of LLD with EFD.

METHODS

Seventeen older adults with depression and EFD were randomized to iTBS or sham for 6 weeks. Intervention was delivered bilaterally using a recognized connectivity target.

RESULTS

A total of 89% (17/19) participants completed all study procedures. No serious adverse events occurred. Pre to post-intervention change in mean Montgomery-Asberg-depression scores was not different between iTBS or sham, p = 0.33. No significant group-by-time interaction for Montgomery-Asberg Depression rating scale scores (F _{3, 44}  = 0.51; p = 0.67) was found. No significant differences were seen in the effects of time between the two groups on executive measures: Flanker scores (F _{1, 14}  = 0.02, p = 0.88), Dimensional-change-card-sort scores F _{1, 14}  = 0.25, p = 0.63, and working memory scores (F _{1, 14}  = 0.98, p = 0.34). The Group-by-time interaction effect for functional connectivity (FC) within the Fronto-parietal-network was not significant (F _{1, 14}  = 0.36, p = 0.56). No significant difference in the effect-of-time between the two groups was found on FC within the Cingulo-opercular-network (F _{1, 14}  = 0, p = 0.98).

CONCLUSION

Bilateral iTBS is feasible in LLD. Preliminary results are unsupportive of efficacy on depression, executive function or target engagement of the CCN. A future Randomized clinical trial requires a larger sample size with stratification of cognitive and executive variables and refinement in the target engagement.

Theory-of-mind abilities in older patients with common mental disorders - a cross-sectional study

OBJECTIVES

Theory-of-mind (ToM) abilities are a basic competence for social interactions and relationships. Numerous findings demonstrate ToM deficits in old age, but such findings are missing in clinical samples of older adults.

METHOD

In the present study, patients treated in two clinics for common mental disorders (N = 150, distributed among the age groups 40-54, 55-69 and ≥70) were compared with a sample of people of the same age without mental disorders. The Reading the Mind in the Eyes Test (RMET) was used, in which the task is to detect mental states in the eyes, which are presented in 36 pictures.

RESULTS

The two groups differed significantly from each other: the clinical samples achieved worse results than the nonclinical samples, and the older samples achieved worse results than the younger samples. In the multiple regression analysis significant beta-weights were found for executive functions, physical diseases (especially vascular diseases, in the clinical sample) and higher education.

CONCLUSION

Older patients show clinically significant deficits in ToM abilities, which should be taken into account in interventions promoting ToM abilities.

Cold Cognition as Predictor of Treatment Response to rTMS; A Retrospective Study on Patients With Unipolar and Bipolar Depression

Background

Cognitive impairments are prevalent in patients with unipolar and bipolar depressive disorder (UDD and BDD, respectively). Considering the fact assessing cognitive functions is increasingly feasible for clinicians and researchers, targeting these problems in treatment and using them at baseline as predictors of response to treatment can be very informative.

Method

In a naturalistic, retrospective study, data from 120 patients (Mean age: 33.58) with UDD (n = 56) and BDD (n = 64) were analyzed. Patients received 20 sessions of bilateral rTMS (10 Hz over LDLPFC and 1 HZ over RDLPFC) and were assessed regarding their depressive symptoms, sustained attention, working memory, and executive functions, using the Beck Depression Inventory (BDI-II) and Neuropsychological Test Automated Battery Cambridge, at baseline and after the end of rTMS treatment course. Generalized estimating equations (GEE) and logistic regression were used as the main statistical methods to test the hypotheses.

Results

Fifty-three percentage of all patients (n = 64) responded to treatment. In particular, 53.1% of UDD patients (n = 34) and 46.9% of BDD patients (n = 30) responded to treatment. Bilateral rTMS improved all cognitive functions (attention, working memory, and executive function) except for visual memory and resulted in more modulations in the working memory of UDD compared to BDD patients. More improvements in working memory were observed in responded patients and visual memory, age, and sex were determined as treatment response predictors. Working memory, visual memory, and age were identified as treatment response predictors in BDD and UDD patients, respectively.

Conclusion

Bilateral rTMS improved cold cognition and depressive symptoms in UDD and BDD patients, possibly by altering cognitive control mechanisms (top-down), and processing negative emotional bias.

Elevated homocysteine levels, white matter abnormalities and cognitive impairment in patients with late-life depression

Background

Cognitive impairment in late−life depression (LLD) is considered to be caused by neurodegenerative changes. Elevated homocysteine (Hcy) levels may be linked to cognitive abnormalities associated with LLD. The important role of white matter (WM) damage in cognitive impairment and pathogenesis in patients with LLD has been widely reported. However, no research has explored the interrelationships of these features in patients with LLD.

Objective

The goal of the study was to examine the interrelationship between Hcy levels, cognition, and variations in WM microstructure detected by diffusion tensor imaging (DTI) in patients with LLD.

Methods

We recruited 89 healthy controls (HCs) and 113 patients with LLD; then, we measured the plasma Hcy levels of participants in both groups. All individuals performed a battery of neuropsychological tests to measure cognitive ability. Seventy-four patients with LLD and 68 HCs experienced a DTI magnetic resonance imaging (MRI) scan.

Results

Patients with LLD showed significantly lower fractional anisotropy (FA) values in the bilateral inferior longitudinal fasciculus than those of healthy participants. Only in LLD patients was Hcy concentration inversely associated to FA values in the forceps minor. Finally, multiple regression analyses showed that an interaction between Hcy levels and FA values in the right cingulum of the cingulate cortex and right inferior longitudinal fasciculus were independent contributors to the executive function of patients with LLD.

Conclusion

Our results highlight the complex interplay between elevated homocysteine levels and WM abnormalities in the pathophysiology of LLD-related cognitive impairment, consistent with the neurodegeneration hypothesis.

A Network Analysis of Depressive Symptoms in the Elderly with Subjective Memory Complaints

(1) Background: Subjective memory complaints (SMCs) are common among the elderly and are important because they can indicate early cognitive impairment. The factor with the greatest correlation with SMCs is depression. The purpose of this study is to examine depressive symptoms among elderly individuals with SMCs through a network analysis that can analyze disease models between symptoms; (2) Methods: A total of 3489 data collected from elderly individuals in the community were analyzed. The Subjective Memory Complaints Questionnaire and Patient Health Questionnaire-9 were evaluated. For statistical analysis, we investigated the features of the depressive symptoms network, including centrality and clustering; (3) Results: Network analysis of the SMC group showed strong associations in the order of Q1–Q2 (r = 0.499), Q7–Q8 (r = 0.330), and Q1–Q6 (r = 0.239). In terms of centrality index, Q2 was highest in strength and expected influence, followed by Q1 in all of betweenness, strength, and expected influence; (4) Conclusions: The network analysis confirmed that the most important factors in the subjective cognitive decline group were depressed mood and anhedonia, which also had a strong correlation in the network pattern.

The P300, loneliness, and depression in older adults

Depression is associated with high levels of cognitive impairment and increased loneliness among older adults. The current study examines associations between a reliable and robust neural marker of cognitive impairment (i.e., the P300 event-related brain potential [ERP]), loneliness, and depression and assesses the role of loneliness in the P300─depression relationship. In a community sample of 70 older adults between 61 and 75 years, we evaluated cross-sectional associations between depressive symptoms (Geriatric Depression Scale), loneliness (NIH Toolbox), and P300 amplitude measured from the electroencephalogram during a go/no-go task. Results indicated that reduced go and no-go P300 amplitudes were associated with increased depressive symptom severity, with the most unique variance accounted for by a reduced no-go P300 amplitude. Notably, loneliness significantly moderated the no-go P300-depressive symptom severity relationship, such that there was no relationship between the no-go P300 and depressive symptom severity among older adults reporting low levels of loneliness. This finding provides insight into the possibility that social support may offer protection against the depressogenic effects of poor inhibitory control in older adults. Taken together, this study provides a novel examination of the relationships between depression, loneliness, and the P300 ERP in older adults, with important implications for understanding the role of neural inhibition and loneliness in relation to depressive symptomatology.

Late-Life Depression, Cognitive Impairment, and Relationship with Alzheimer's Disease

This narrative review aimed to explore the existing knowledge in order to examine the multiple forms of late-life depression (LLD) within a non-neurodegenerative or a neurodegenerative context, in particular Alzheimer's disease (AD). This review will first provide information about different pathogenic hypotheses proposed to describe LLD when it is not linked to a neurodegenerative context. Within the presentation of these syndromes, the literature reports thymic and cognitive specific features and highlights a common preponderance of cognitive impairment, and particularly executive. This review will also report data from research works that have addressed the role of depressive symptoms (DSs) in incidence of AD and mild cognitive impairment (MCI) conversion to AD. These findings support the claim that the relationship between DS (or LLD) and the cognitive decline encountered in AD can be of 2 types: (1) risk factor or (2) prodrome. They also support the hypothesis that the effect of DS on the incidence of AD can be identified between specific characteristics of these symptoms such as a very first apparition late in life, an increasing severity of DS, and a poor response to medical treatment. Finally, longitudinal and cross-sectional research will be presented, aiming to identify the predictive value of DS (or LLD) on AD incidence and/or conversion of MCI (and specifically amnestic MCI). This final section shows that specific features of LLD, such as being of early- or late-onset, can be considered as indices of AD incidence.

Influences of dopaminergic system dysfunction on late-life depression

Deficits in cognition, reward processing, and motor function are clinical features relevant to both aging and depression. Individuals with late-life depression often show impairment across these domains, all of which are moderated by the functioning of dopaminergic circuits. As dopaminergic function declines with normal aging and increased inflammatory burden, the role of dopamine may be particularly salient for late-life depression. We review the literature examining the role of dopamine in the pathogenesis of depression, as well as how dopamine function changes with aging and is influenced by inflammation. Applying a Research Domain Criteria (RDoC) Initiative perspective, we then review work examining how dopaminergic signaling affects these domains, specifically focusing on Cognitive, Positive Valence, and Sensorimotor Systems. We propose a unified model incorporating the effects of aging and low-grade inflammation on dopaminergic functioning, with a resulting negative effect on cognition, reward processing, and motor function. Interplay between these systems may influence development of a depressive phenotype, with an initial deficit in one domain reinforcing decline in others. This model extends RDoC concepts into late-life depression while also providing opportunities for novel and personalized interventions.

Association of White Matter Integrity With Executive Function and Antidepressant Treatment Outcome in Patients With Late-Life Depression

OBJECTIVE

While patients with late-life depression (LLD) often exhibit microstructural white matter alterations that can be identified with diffusion tensor imaging (DTI), there is a dearth of information concerning the links between DTI findings and specific cognitive performance, as well as between DTI measures and antidepressant treatment outcomes.

DESIGN

Neuroimaging and cognitive tests were conducted at baseline in 71 older adults participating in a larger, 8-week duration antidepressant randomized controlled trial. Correlations between DTI measures of white matter integrity evaluated with tract-based spatial statistics, baseline neurocognitive performance, and prospective antidepressant treatment outcome were evaluated.

RESULTS

Fractional anisotropy (FA), an index of white matter integrity, was significantly positively associated with better cognitive function as measured by the Initiation/Perseveration subscale of the Dementia Rating Scale in the bilateral superior longitudinal fasciculus (SLF), bilateral SLF-temporal, and right corticospinal tract (CST). An exploratory analysis limited to these tracts revealed that increased FA in the right CST, right SLF, and right SLF-temporal tracts was correlated with a greater decrease in depressive symptoms. Increased FA in the right CST predicted a greater chance of remission, while increased FA in the right CST and the right SLF predicted a greater chance of treatment response.

CONCLUSION

In late-life depression LLD subjects, white matter integrity was positively associated with executive function in white matter tracts which act as key connecting structures underlying the cognitive control network. These tracts may play a role as a positive prognostic factor in antidepressant treatment outcome.

Cognitive Impairment in Late-Life Depression: A Comparative Study of Healthy Older People, Late-Life Depression, and Mild Alzheimer's Disease Using Multivariate Base Rates of Low Scores

Late-Life Depression (LLD) is often associated with cognitive impairment. However, distinction between cognitive impairment due to LLD and those due to normal aging or mild Alzheimer's Disease (AD) remain difficult. The aim of this study was to present and compare the multivariate base rates of low scores in LLD, mild AD, and healthy control groups on a battery of neuropsychological tests. Participants (ages 60-89) were 352 older healthy adults, 390 patients with LLD, and 234 patients with mild AD (i.e., MMSE ≥ 20). Multivariate base rates of low scores (i.e., ≤ 5th percentile) were calculated for each participant group within different cognitive domains (verbal episodic memory, executive skills, mental processing speed, constructional praxis, and language/semantic memory). Obtaining at least one low score was relatively common in healthy older people controls (from 9.4 to 17.6%), and may thus result in a large number of false positives. By contrast, having at least two low scores was unusual (from 0.3 to 4.6%) and seems to be a more reliable criterion for identifying cognitive impairment in LLD. Having at least three low memory scores was poorly associated with LLD (5.9%) compared to mild AD (76.1%) and may provide a useful way to differentiate between these two conditions [χ ( 1 ) 2 = 329.8, p < 0.001; Odds Ratio = 50.7, 95% CI = 38.2-77.5]. The multivariate base rate information about low scores in healthy older people and mild AD may help clinicians to identify cognitive impairments in LLD patients, improve the clinical decision-making, and target those who require regular cognitive and clinical follow-up.

Effectiveness of Safinamide over Mood in Parkinson's Disease Patients: Secondary Analysis of the Open-label Study SAFINONMOTOR

INTRODUCTION

Mood disorders are frequent in Parkinson's disease (PD) and a favorable effect of safinamide on mood has been observed. We aimed to analyze the effectiveness of safinamide on mood as a secondary objective from the SAFINONMOTOR (an open-label study of the effectiveness of SAFInamide on NON-MOTOR symptoms in patients with Parkinson's disease) study.

METHODS

SAFINONMOTOR is a prospective open-label single-arm study conducted in five centers from Spain. Patients with PD were required to have at baseline a Non-Motor Symptoms Scale (NMSS) total score of at least 40. In this analysis, the changes from V1 (baseline) to V4 (6 months ± 1 month) in the BDI-II (Beck Depression Inventory-II), NMSS mood/apathy domain, and PDQ-39 (Parkinson's Disease Questionnaire-39) emotional well-being domain were analyzed. Depression was identified and classified (DSM-IV and Judd criteria) at baseline and at the end of follow-up as major depression (MD), minor depression (mD), subthreshold depression (subD), and non-depression (nonD).

RESULTS

Fifty patients with PD were included (age 68.5 ± 9.12 years; 58% women; 6.4 ± 5.1 years from diagnosis) and 44 patients (88%) completed the follow-up at 6 months. The BDI-II total score was reduced by 35.9% (from 15.88 ± 10.46 at V1 to 10.18 ± 6.76 at V4; p < 0.0001). A significant decrease in the NMSS mood/apathy domain and PDQ-39 emotional well-being domain was observed as well (p < 0.0001). At baseline, 52% of the patients presented MD, 34% mD, 12% subD, and 2% nonD whereas at V4 the percentages were 31.8%, 34.1%, 22.7%, and 11.4%, respectively (p = 0.029).

CONCLUSIONS

Safinamide improves mood in patients with PD at 6 months.

Be Fit, Be Sharp, Be Well: The Case for Exercise as a Treatment for Cognitive Impairment in Late-life Depression

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.

Brain-based mechanisms of late-life depression: Implications for novel interventions

Late-life depression (LLD) is a particularly debilitating illness. Older adults suffering from depression commonly experience poor outcomes in response to antidepressant treatments, medical comorbidities, and declines in daily functioning. This review aims to further our understanding of the brain network dysfunctions underlying LLD that contribute to disrupted cognitive and affective processes and corresponding clinical manifestations. We provide an overview of a network model of LLD that integrates the salience network, the default mode network (DMN) and the executive control network (ECN). We discuss the brain-based structural and functional mechanisms of LLD with an emphasis on their link to clinical subtypes that often fail to respond to available treatments. Understanding the brain networks that underlie these disrupted processes can inform the development of targeted interventions for LLD. We propose behavioral, cognitive, or computational approaches to identifying novel, personalized interventions that may more effectively target the key cognitive and affective symptoms of LLD.

Subtypes of Late-Life Depression: A Data-Driven Approach on Cognitive Domains and Physical Frailty

BACKGROUND

With increasing age, symptoms of depression may increasingly overlap with age-related physical frailty and cognitive decline. We aim to identify late-life-related subtypes of depression based on measures of depressive symptom dimensions, cognitive performance, and physical frailty.

METHODS

A clinical cohort study of 375 depressed older patients with a DSM-IV depressive disorder (acronym NESDO). A latent profile analysis was applied on the three subscales of the Inventory of Depressive Symptomatology, as well as performance in five cognitive domains and two proxies for physical frailty. For each class, we investigated remission, dropout, and mortality at 2-year follow-up as well as change over time of depressive symptom severity, cognitive performance, and physical frailty.

RESULTS

A latent profile analysis model with five classes best described the data, yielding two subgroups suffering from pure depression ("mild" and "severe" depression, 55% of all patients) and three subgroups characterized by a specific profile of cognitive and physical frailty features, labeled as "amnestic depression," "frail-depressed, physically dominated," and "frail-depressed, cognitively dominated." The prospective analyses showed that patients in the subgroup of "mild depression" and "amnestic depression" had the highest remission rates, whereas patients in both frail-depressed subgroups had the highest mortality rates.

CONCLUSIONS

Late-life depression can be subtyped by specific combinations of age-related clinical features, which seems to have prospective relevance. Subtyping according to the cognitive profile and physical frailty may be relevant for studies examining underlying disease processes as well as to stratify treatment studies on the effectiveness of antidepressants, psychotherapy, and augmentation with geriatric rehabilitation.

A digital intervention targeting cognitive control network dysfunction in middle age and older adults with major depression

Nonpharmacological interventions targeting putative network mechanisms of major depressive disorder (MDD) may represent novel treatments. This mechanistic study investigates how a video game-like intervention, designed to improve cognitive control network (CCN) functioning by targeting multitasking, influences the CCN of middle-aged and older adults with MDD. The sample consisted of 34 adults aged 45-75 with SCID-defined diagnosis of MDD, Hamilton depression rating scale scores ≥20, and a deficit in cognitive control. Participants were instructed to play at home for 20-25 min per day, at least 5 times per week, for 4 weeks. Evidence of target engagement was defined a priori as >2/3 of participants showing CCN improvement. CCN engagement was defined as a change in a Z score of ≥0.5 on functional magnetic resonance imaging (fMRI) in activation and functional connectivity of the CCN during task-based and resting-state fMRI, respectively. 74% of participants showed a change in activation of the CCN, and 72% showed an increase in resting-state functional connectivity. Sixty-eight percent demonstrated improved cognitive control function, measured as either improvement on sustained attention or working memory performance or reduced self-reported symptoms of apathy on the frontal systems behavioral scale (FrsBe). Participants also reported a significant reduction in mood symptoms measured by PHQ-9. A remotely deployed neuroscience-informed video game-like intervention improves both CCN functions and mood in middle-aged and older adults with MDD. This easily-disseminated intervention may rescue CCN dysfunction present in a substantial subset of middle-aged and older adults with MDD.

Crosstalk between Existential Phenomenological Psychotherapy and Neurological Sciences in Mood and Anxiety Disorders

Psychotherapy is a comprehensive biological treatment modifying complex underlying cognitive, emotional, behavioral, and regulatory responses in the brain, leading patients with mental illness to a new interpretation of the sense of self and others. Psychotherapy is an art of science integrated with psychology and/or philosophy. Neurological sciences study the neurological basis of cognition, memory, and behavior as well as the impact of neurological damage and disease on these functions, and their treatment. Both psychotherapy and neurological sciences deal with the brain; nevertheless, they continue to stay polarized. Existential phenomenological psychotherapy (EPP) has been in the forefront of meaning-centered counseling for almost a century. The phenomenological approach in psychotherapy originated in the works of Martin Heidegger, Ludwig Binswanger, Medard Boss, and Viktor Frankl, and it has been committed to accounting for the existential possibilities and limitations of one's life. EPP provides philosophically rich interpretations and empowers counseling techniques to assist mentally suffering individuals by finding meaning and purpose to life. The approach has proven to be effective in treating mood and anxiety disorders. This narrative review article demonstrates the development of EPP, the therapeutic methodology, evidence-based accounts of its curative techniques, current understanding of mood and anxiety disorders in neurological sciences, and a possible converging path to translate and integrate meaning-centered psychotherapy and neuroscience, concluding that the EPP may potentially play a synergistic role with the currently prevailing medication-based approaches for the treatment of mood and anxiety disorders.

Crosstalk between Depression and Dementia with Resting-State fMRI Studies and Its Relationship with Cognitive Functioning

Alzheimer’s disease (AD) is the most common type of dementia, and depression is a risk factor for developing AD. Epidemiological studies provide a clinical correlation between late-life depression (LLD) and AD. Depression patients generally remit with no residual symptoms, but LLD patients demonstrate residual cognitive impairment. Due to the lack of effective treatments, understanding how risk factors affect the course of AD is essential to manage AD. Advances in neuroimaging, including resting-state functional MRI (fMRI), have been used to address neural systems that contribute to clinical symptoms and functional changes across various psychiatric disorders. Resting-state fMRI studies have contributed to understanding each of the two diseases, but the link between LLD and AD has not been fully elucidated. This review focuses on three crucial and well-established networks in AD and LLD and discusses the impacts on cognitive decline, clinical symptoms, and prognosis. Three networks are the (1) default mode network, (2) executive control network, and (3) salience network. The multiple properties emphasized here, relevant for the hypothesis of the linkage between LLD and AD, will be further developed by ongoing future studies.

A Lifespan Model of Interference Resolution and Inhibitory Control: Risk for Depression and Changes with Illness Progression

The cognitive processes involved in inhibitory control accuracy (IC) and interference resolution speed (IR) or broadly - inhibition - are discussed in this review, and both are described within the context of a lifespan model of mood disorders. Inhibitory control (IC) is a binary outcome (success or no for response selection and inhibition of unwanted responses) for any given event that is influenced to an extent by IR. IR refers to the process of inhibition, which can be manipulated by task design in earlier and later stages through use of distractors and timing, and manipulation of individual differences in response proclivity. We describe the development of these two processes across the lifespan, noting factors that influence this development (e.g., environment, adversity and stress) as well as inherent difficulties in assessing IC/IR prior to adulthood (e.g., cross-informant reports). We use mood disorders as an illustrative example of how this multidimensional construct can be informative to state, trait, vulnerability and neuroprogression of disease. We present aggregated data across numerous studies and methodologies to examine the lifelong development and degradation of this subconstruct of executive function, particularly in mood disorders. We highlight the challenges in identifying and measuring IC/IR in late life, including specificity to complex, comorbid disease processes. Finally, we discuss some potential avenues for treatment and accommodation of these difficulties across the lifespan, including newer treatments using cognitive remediation training and neuromodulation.

Predictors of serious suicidal behavior in late-life depression

The present study aimed to identify pathways to suicidal behavior in late life that can guide identification of those most at risk and improve treatment. In a longitudinal study of late-life depression, we prospectively assessed risk factors specifically associated with fatal and near-fatal as compared to less lethal suicidal behavior. We enrolled 401 participants (age 66+9.9): 311 with unipolar non-psychotic depression and 90 non-psychiatric controls. The median follow-up was 5.4 years. Results indicated that history of suicide attempt predicted a two-fold increase in the risk of dying from natural causes. In univariate models, male gender, higher income, current depression and current and worst lifetime suicidal ideation severity, cognitive control deficits, and low levels of non-planning impulsivity predicted fatal and near-fatal suicidal behavior. In contrast, incident less lethal suicidal behavior was mostly associated with maladaptive personality traits, impulsivity, and severity of psychiatric illness in univariate models. In multipredictor models, male gender, worst lifetime suicidal ideation, and deficits in cognitive control independently predicted fatal/near-fatal suicidal behavior, while introversion, history of suicide attempt, and earlier age of onset of depression predicted less lethal suicidal behavior. While clinicians may be familiar with suicide risk factors identified in younger samples such as dysfunctional personality, impulsivity, and co-morbid substance use, in late life these characteristics only pertain to lower-lethality suicidal behavior. Cognitive control deficits, which likely play a greater role in old age, predict serious suicidal behavior.

Self-rated Physical, Mental, Oral, and Cognitive Health in Older Korean Immigrants: The Role of Health Indicators and Sociocultural Factors

Objectives:

Guided by the models of health assessment and social determinants of health, we examined predictors of self-rated physical, mental, oral, and cognitive health of older Korean immigrants.

Methods:

Data came from the Study of Older Korean Americans (SOKA; N = 2,061, Mean age = 73.2). Multivariate regression models of self-ratings of health were tested with health indicators (both domain-specific and other health indicators including chronic disease, functional disability, problems with teeth or gums, and cognitive function) and sociocultural factors (acculturation, social network, and ethnic community social cohesion).

Results:

For self-rated physical, mental, and oral health, indicators specific to the targeted domain played a primary role, with those of other health domains playing a secondary role. Acculturation and social network were significant predictors of all four measures.

Discussion:

Findings highlight the importance of holistic health assessment that considers a wide range of health domains as well as sociocultural contexts.

Targeting Cognitive Control Deficits With Neuroplasticity-Based Computerized Cognitive Remediation in Patients With Geriatric Major Depression: A Randomized, Double-Blind, Controlled Trial

Late life major depression (LLD) is often accompanied by cognitive deficits. When patients have specific deficits in cognitive control functions (CCD), they are not only distressing and debilitating, they often predict poor clinical outcomes such as reduced response to SSRI/SNRI antidepressants, increased disability, suicide and all-cause mortality. We recently reported that in an open label trial, our treatment designed to target these specific CCD with neuroplasticity-based computerized cognitive remediation (nCCR) improved depression and CCD in patients who failed to remit with conventional antidepressant treatment. This study tested the hypothesis that in patients with LLD who have failed at least one trial of an SSRI/SNRI antidepressant at an adequate dose for at least 8 weeks, nCCR will improve both depressive symptoms and the CCD associated with poor antidepressant response (i.e. semantic strategy, inhibition of prepotent responses) more than an active control group. Participants were randomized (1:1) to receive either 30 hours/ 4 weeks of neuroplasticity based computerized cognitive remediation (nCCR) designed to target CCD, or the active control condition matched for duration, engagement, reward, computer presentation, and contact with study staff. All participants and raters were blinded. Mixed effects model analysis the time effect (week) (F(1,71.22)=25.2, p<0.0001) and treatment group X time interaction (F(1,61.8)=11.37, p=.002) reached significance indicating that the slope of decline in MADRS was steeper in the nCCR-GD group. Further, the nCCR group improved their semantic clustering strategy(t(28)=9.5; p=.006), as well as performance on the Stroop interference condition, and cognitive flexibility (Trails B). Further, results transferred to memory performance, which was not a function trained by nCCR. clinicaltrials.gov.

A bayesian approach to examining default mode network functional connectivity and cognitive performance in major depressive disorder

To reconcile the inconsistency of the association between the resting-state functional connectivity (RSFC) and cognitive performance in healthy and depressed groups due to high variance of both measures, we proposed a Bayesian spatio-temporal model to precisely and accurately estimate the RSFC in depressed and nondepressed participants. This model was employed to estimate spatially-adjusted functional connectivity (saFC) in the extended default mode network (DMN) that was hypothesized to correlate with cognitive performance in both depressed and nondepressed. Multiple linear regression models were used to study the relationship between DMN saFC and cognitive performance scores measured in the following four cognitive domains while adjusting for age, sex, and education. In ROI pairs including the posterior cingulate (PCC) and anterior cingulate (ACC) cortex regions, the relationship between connectivity and cognition was found only with the Bayesian approach. Moreover, only the Bayesian approach was able to detect a significant diagnostic difference in the association in ROI pairs, including both PCC and ACC regions, due to smaller variance for the saFC estimator. The results confirm that a reliable and precise saFC estimator, based on the Bayesian model, can foster scientific discovery that may not be feasible with the conventional ROI-based FC estimator (denoted as 'AVG-FC').

Dimensions of Poststroke Depression and Neuropsychological Deficits in Older Adults

OBJECTIVE

Poststroke depression (PSD) has a heterogeneous presentation and is often accompanied by cognitive impairment. This study aimed to identify distinct dimensions of depressive symptoms in older adults with PSD and to evaluate their relationship to cognitive functioning.

DESIGN

Cross-sectional factor and correlational analyses of patients with poststroke depression.

SETTING

Patients were recruited from the community and from acute inpatient stroke rehabilitation hospitals.

PARTICIPANTS

Participants had suffered a stroke and met DSM-IV criteria for major depression (≥18 Montgomery Åsberg Depression Scale; MADRS).

INTERVENTION

None.

MEASUREMENTS

MADRS was used to quantify depression severity at study entry. Neuropsychological assessment at the time of study entry consisted of measures of Global Cognition, Attention, Executive Function, Processing Speed, Immediate Memory, Delayed Memory, and Language.

RESULTS

There were 135 (age ≥50) older adult participants with PSD and varying degrees of cognitive impairment (MMSE Total ≥20). Factor analysis of the MADRS identified three factors, that is sadness, distress, and apathy. Items comprising each factor were totaled and correlated with neuropsychological domain z-score averages. Symptoms of the apathy factor (lassitude, inability to feel) were significantly associated with greater impairment in executive function, memory, and global cognition. Symptoms of the sadness and distress factors had no relationship to cognitive impairment.

CONCLUSION

PSD consists of three correlated dimensions of depressive symptoms. Apathy symptoms are associated with cognitive impairment across several neuropsychological domains. PSD patients with prominent apathy may benefit from careful attention to cognitive functions and by interventions that address both psychopathology and behavioral deficits resulting from cognitive impairment.

Associations of cardiovascular disease and depression with memory related disease: A Chinese national prospective cohort study

BACKGROUND

Association of cardiovascular disease (CVD) or depression and memory has been studied. But hardly any studies on the association of coexistence of CVD and depression and memory.

METHODS

This is a prospective cohort study of a nationally representative sample of 12,272 adults aged 45 years and more who participated in the China health and retirement longitudinal study 2011 to 2015. All variables were acquired by self-reporting questions. The associations between coexistence of CVD and depression with memory related disease (MRD) were investigated by using Cox proportional hazards regression models.

RESULTS

Among the 12,272 participants (mean age 65.69 years; 46.8% male) in this study, 56.9% no CVD or depression and 6.7% coexistence of CVD and depression. After adjustment for age, sex, marriage, living place, registered permanent residence, education level, smoking status, alcoholic intake, sleep status, nap status, social communication, health before 15 years, life satisfaction, cognitive function, and 11 chronic diseases risk factors, depression alone was significantly high risk for MRD (HR:1.64; 95% CI: 1.09-2.49); coexistence of CVD and depression increased the risk for MRD significantly higher (HR: 4.72; 95%CI: 2.91-7.64).

LIMITATIONS

Diseases were all self-reported and we couldn't adjust for all the potential confounders, which might be prone to information error and residual confounding.

CONCLUSIONS

In a nationally representative cohort with median 4 years of follow-up, depression alone and co-existence of depression and CVD could significantly increase the risk of MRD. Our study supports the idea of prevention of memory disease from a psycho-cardiology aspect.

Depression, cognitive, and functional outcomes of Problem Adaptation Therapy (PATH) in older adults with major depression and mild cognitive deficits

OBJECTIVES

Antidepressants have limited efficacy in older adults with depression and cognitive impairment, and psychosocial interventions for this population have been inadequately investigated. Problem Adaptation Therapy (PATH) is a psychosocial intervention for older adults with major depression, cognitive impairment, and disability.

DESIGN

This study tests the efficacy of PATH versus Supportive Therapy for Cognitively Impaired Older Adults (ST-CI) in reducing depression (Montgamery Asberg Depression Rating Scale [MADRS]) and disability (World Health Organization Disability Assessments Schedule-II [WHODAS-II]) and improving cognitive outcomes (Mini Mental State Examination [MMSE]) over 24 weeks (12 weeks of treatment and 12-week post-treatment follow-up).

SETTING

Participants were recruited through collaborating community agencies of Weill Cornell Institute of Geriatric Psychiatry. Both interventions and all research assessments were conducted at home.

PARTICIPANTS

Thirty-five older adults (age ≥ 65 years) with major depression and cognitive impairment no dementia (CIND).

INTERVENTIONS

PATH aims to increase emotion regulation by incorporating a problem-solving approach, teaching compensatory strategies, and inviting caregiver participation. Supportive Therapy aims to facilitate the expression of affect, as well as promote empathy.

MEASUREMENTS

Depression was measured using the MADRS, disability using the WHODAS-II, and cognition using the MMSE.

RESULTS

PATH participants showed significantly greater reduction in MADRS total score (7.04 points at 24 weeks, treatment group by time interaction: F[1,24.4] = 7.61, p = 0.0108), greater improvement in MMSE total score (2.30 points at 24 weeks, treatment group by time interaction: F[1,39.8] = 13.31, p = 0.0008), and greater improvement in WHODAS-II total score (2.95 points at 24 weeks, treatment group by time interaction: F[1,89] = 4.93, p = 0.0290) than ST-CI participants over the 24-week period.

CONCLUSIONS

PATH participants had better depression, cognitive, and disability outcomes than ST-CI participants over 6 months. PATH may provide relief to depressed older adults with CIND who currently have limited treatment options.

Cognitive Control Network Homogeneity and Executive Functions in Late-Life Depression

BACKGROUND

Late-life depression is characterized by network abnormalities, especially within the cognitive control network. We used alternative functional connectivity approaches, regional homogeneity (ReHo) and network homogeneity, to investigate late-life depression functional homogeneity. We examined the association between cognitive control network homogeneity and executive functions.

METHODS

Resting-state functional magnetic resonance imaging data were analyzed for 33 older adults with depression and 43 healthy control subjects. ReHo was performed as the correlation between each voxel and the 27 neighbor voxels. Network homogeneity was calculated as global brain connectivity restricted to 7 networks. T-maps were generated for group comparisons. We measured cognitive performance and executive functions with the Dementia Rating Scale, Trail-Making Test (A and B), Stroop Color Word Test, and Digit Span Test.

RESULTS

Older adults with depression showed increased ReHo in the bilateral dorsal anterior cingulate cortex (dACC) and the right middle temporal gyrus, with no significant findings for network homogeneity. Hierarchical linear regression models showed that higher ReHo in the dACC predicted better performance on Trail-Making Test B (p < .001; R2 = .49), Digit Span Backward (p < .05; R2 = .23), and Digit Span Total (p < .05; R2 = .23). Used as a seed, the dACC cluster of higher ReHo showed lower functional connectivity with bilateral precuneus.

CONCLUSIONS

Higher ReHo within the dACC and right middle temporal gyrus distinguish older adults with depression from control subjects. The correlations with executive function performance support increased ReHo in the dACC as a meaningful measure of the organization of the cognitive control network and a potential compensatory mechanism. Lower functional connectivity between the dACC and the precuneus in late-life depression suggests that clusters of increased ReHo may be functionally segregated.

Associations of cardiovascular disease and depression with memory related disease: A Chinese national prospective cohort study

BACKGROUND

Association of cardiovascular disease (CVD) or depression and memory has been studied. But hardly any studies on the association of coexistence of CVD and depression and memory.

METHODS

This is a prospective cohort study of a nationally representative sample of 12,272 adults aged 45 years and more who participated in the China health and retirement longitudinal study 2011 to 2015. All Variables were acquired by self-reporting questions. The associations between coexistence of CVD and depression with memory related disease (MRD) were investigated by using Cox proportional hazards regression models.

RESULTS

Among the 12,272 participants (mean age 65.69 years; 46.8% male) in this study, 56.9% no CVD or depression and 6.7% coexistence of CVD and depression. After adjustment for age, sex, marriage, living place, registered permanent residence, education level, smoking status, alcoholic intake, sleep status, nap status, social communication, health before 15 years, life satisfaction, cognitive function, and 11 chronic diseases risk factors, depression alone was significantly high risk for MRD (HR:1.64; 95% CI: 1.09-2.49); coexistence of CVD and depression increased the risk for MRD significantly higher (HR: 4.72; 95%CI: 2.91-7.64).

LIMITATIONS

Diseases were all self-reported and we couldn't adjust for all the potential confounders, which might be prone to information error and residual confounding.

CONCLUSIONS

In a nationally representative cohort with median 4 years of follow-up, depression alone and coexistence of depression and CVD could significantly increase the risk of MRD. Our study supports the idea of prevention of memory disease from a psycho-cardiology aspect.

Disruption of Neural Homeostasis as a Model of Relapse and Recurrence in Late-Life Depression

The significant public health burden associated with late-life depression (LLD) is magnified by the high rates of recurrence. In this manuscript, we review what is known about recurrence risk factors, conceptualize recurrence within a model of homeostatic disequilibrium, and discuss the potential significance and challenges of new research into LLD recurrence. The proposed model is anchored in the allostatic load theory of stress. We review the allostatic response characterized by neural changes in network function and connectivity and physiologic changes in the hypothalamic-pituitary-adrenal axis, autonomic nervous system, immune system, and circadian rhythm. We discuss the role of neural networks' instability following treatment response as a source of downstream disequilibrium, triggering and/or amplifying abnormal stress response, cognitive dysfunction and behavioral changes, ultimately precipitating a full-blown recurrent episode of depression. We propose strategies to identify and capture early change points that signal recurrence risk through mobile technology to collect ecologically measured symptoms, accompanied by automated algorithms that monitor for state shifts (persistent worsening) and variance shifts (increased variability) relative to a patient's baseline. Identifying such change points in relevant sensor data could potentially provide an automated tool that could alert clinicians to at-risk individuals or relevant symptom changes even in a large practice.

High-definition transcranial direct current stimulation-An open-label pilot intervention in alleviating depressive symptoms and cognitive deficits in late-life depression

The efficacy of high-definition transcranial direct current stimulation (HD-tDCS) in late-life depression (LLD) remains unknown due to limited research on its therapeutic effects on the hallmarks of LLD-the depressive and cognitive symptoms. The present open-label pilot study aimed to examine the effectiveness of HD-tDCS as an augmentation therapy with antidepressants in improving the depressive and cognitive symptoms for LLD. Significant improvements were hypothesized in the depressive, cognitive, and daily functioning outcomes over time. A total of 15 subjects with LLD (13 females, mean age = 73.27 ± 6.25) received five consecutive daily sessions of 20-minute active HD-tDCS interventions weekly for 2 weeks, with a 2 mA anodal stimulation over F3 and cathodal stimulation over FC1, AF3, F7, and FC5. Depressive symptoms and cognitive and daily functioning were assessed across five assessment timepoints. The results revealed that the HD-tDCS was effective in reducing the depressive severity and the remission rates, with a sustained effect at both the 1-month and 3-month follow-up. Pre-post improvements were seen in the overall cognitive functioning and in verbal fluency, but not in executive functioning. Our pilot study provides a preliminary result of HD-tDCS in LLD, which was a safe and effective treatment in alleviating depressive symptoms, with mild cognitive improvements observed. Further larger scale randomized controlled trials are needed to confirm this result.

Neurocognitive Predictors of Clinical Improvement in Selective Serotonin Reuptake Inhibitor-Treated Adolescents with Major Depressive Disorder

OBJECTIVES

Numerous studies have suggested cognitive deficits as consistently associated with adolescent depression. No study to date, however, has assessed neurocognitive predictors of selective serotonin reuptake inhibitor (SSRI) treatment response in adolescents with depression. This study examined neurocognitive tasks at baseline as predictors of clinical improvement with SSRI treatment (fluoxetine) at week 6 and 12 in an adolescent population.

METHODS

Adolescents with depression were recruited from a child and adolescent psychiatry outpatient clinic at a university medical center. Twenty-four adolescents (mean age 14.8 years) with Major Depressive Disorder completed tasks of the Cambridge Neuropsychological Test Automated Battery, including visual memory, executive functioning, sustained attention, and impulsivity. Depression severity, measured by the Children's Depression Rating Scale-Revised (CDRS-R), was assessed at week 6 and 12 and clinical improvement was defined as percentage (%) change in CDRS-R from baseline.

RESULTS

Clinical improvement is noted at both week 6 (mean % change in CDRS-R [M] = 46.8, standard deviation [SD] = 51.9) and week 12 (M = 87.9, SD = 57.2). Results reveal that less difficulty in sustained attention (p = 0.02), lower impulsivity (p = 0.00), and better planning (p = 0.04) at baseline were predictors of greater clinical improvement at week 6. Lower impulsivity at baseline remained significantly predictive of clinical improvement at week 12 (p = 0.01).

CONCLUSION

Neurocognitive assessments could potentially help identify a subset of depressed adolescents who may not respond to conventional SSRI treatment and who may be better candidates for alternative or augmentation treatments.

Trajectories of major depression in middle-aged and older adults: A population-based study

OBJECTIVES

This study aimed to examine depression trajectories and correlates in a nationally representative sample of middle-aged and older adults in the United States.

METHODS

The study sample consisted of 15 661 participants aged over 50 years from the US Health and Retirement Study. Major depression was assessed using the Composite International Diagnostic Interview (CIDI-SF). Depression trajectories were identified using a group-based trajectory modeling enhanced to account for nonrandom attrition. Multinomial logistic regression was conducted to investigate predictors of depression trajectories.

RESULTS

Four depression trajectory groups were identified: "never" (85.8%), "increasing" (6.3%), "decreasing" (3.2%), and "persistently moderate/high" (4.7%). Baseline depressive symptom severity was a strong predictor of depression trajectories. Older age, male sex, and non-Hispanic African American race were associated with a lower risk of the three trajectories with small to high depression burden, whereas chronic disease count was associated with a higher risk of these trajectories. The risk of being on the increasing trajectory increased with mobility difficulties. Difficulties in household activities predicted membership in the persistently moderate/high group.

CONCLUSIONS

A small but nonignorable proportion of middle-aged and older adults have chronic major depression. Initial symptom severity and chronic disease burden are consistent risk factors for unfavorable depression trajectories and potential targets for screening and intervention.

Cognitive profiles in major depressive disorder: Comparing remitters and non-remitters to rTMS treatment

Major Depressive Disorder (MDD) is typically accompanied by cognitive impairment. Repetitive Transcranial Magnetic Stimulation (rTMS) treatment for MDD involves stimulation of the dorsolateral prefrontal cortex which plays an important role in cognition. This study aimed to identify differences in cognitive profiles between remitters and non-remitters to rTMS at baseline and across treatment. 25 patients with MDD performed cognitive tasks at baseline and after 6, 12 and 30 sessions of rTMS. At baseline, there was no difference in simple reaction time (RT) between groups, but remitters (n = 13) showed faster RTs than non-remitters (n = 12) in the Switch and No-Switch conditions of Task Switching. Across sessions, remitters showed a decrease in 3-Back omission errors and RTs to 3-Back, Stroop's Congruent and Incongruent, and Task Switching's Switch and No-Switch conditions, whereas non-remitters only showed improvements in Stroop Congruent and Incongruent RTs. Baseline and final scores on the Hamilton Depression Rating Scale were positively correlated with Switch and No-Switch RTs. This study demonstrates that eventual remitters to rTMS treatment for MDD perform better in cognitive tasks requiring shifting attention, and this difference is observable prior to the start of treatment. Remitters also show improvement in both their mood and cognitive performance.

An inverse relationship between cortical plasticity and cognitive inhibition in late-life depression

Executive dysfunction is a common and disabling component of late-life depression (LLD), yet its neural mechanisms remain unclear. In particular, it is not yet known how executive functioning in LLD relates to measures of cortical physiology that may change with age and illness, namely cortical inhibition/excitation and plasticity. Here, we used transcranial magnetic stimulation (TMS) to measure cortical inhibition/excitation (n = 51), and the potentiation of cortical activity following paired associative stimulation, which is thought to reflect long-term potentiation (LTP)-like cortical plasticity (n = 32). We assessed the correlation between these measures of cortical physiology and two measures of executive functioning: cognitive inhibition, assessed using the Delis-Kaplan Executive Function System Color-Word Interference ["Stroop"] Test, and cognitive flexibility, assessed using the Trail Making Test. Correlations with recall memory and processing speed were also performed to assess the specificity of any associations to executive functioning. A significant correlation was found between greater LTP-like cortical plasticity and poorer cognitive inhibition, a core executive function (rp = -0.56, p < 0.001). We did not observe significant associations between cortical inhibition/excitation and executive functioning, or between any neurophysiological measure and cognitive flexibility, memory, or processing speed. Our finding that elevated cortical plasticity is associated with diminished cognitive inhibition emphasizes the importance of balanced synaptic strengthening to healthy cognition. More specifically, our findings suggest that hyper-excitability of cortical circuits following repeated cortical activation may promote inappropriate prepotent responses in LLD. LTP-like cortical plasticity might therefore represent a neural mechanism underlying an inhibitory control cognitive endophenotype of LLD.

Neurocognitive performance and repeated-dose intravenous ketamine in major depressive disorder

OBJECTIVE

Ketamine has demonstrated a rapid antidepressant and antisuicidal effect in patients with major depressive disorder (MDD), but the neurocognitive effects of ketamine are relatively unknown. This study aims to examine the neurocognitive effects of six ketamine infusions and the association of baseline neurocognitive function and the change in severity of depressive symptoms after the last infusions.

METHODS

Sixty-four patients with MDD completed six intravenous infusions of ketamine (0.5 mg/kg over 40 min) administered over a 12-day period (Monday-Wednesday-Friday), and were followed by a 2-week observational period. Four domains of neurocognitive function (including speed of processing, working memory, visual learning and verbal learning) were assessed using the MATRICS Consensus Cognitive Battery (MCCB) at 0, 13 and 26 days.

RESULTS

In linear mixed model, significant improvements were found in terms of speed of processing (F = 20.7, p < 0.001) and verbal learning (F = 11.1, p < 0.001). The Sobel test showed the improvement of speed of processing (Sobel test = 2.8, p < 0.001) and verbal learning (Sobel test = 3.6, p < 0.001) were significantly mediated by change in depressive symptoms. Other two neurocognitive domains showed no significant changes over time. Correlation analysis showed no significant association of change in depressive symptoms with neurocognitive function at baseline.

CONCLUSION

Our findings suggest that six ketamine infusions were associated with the improvement of speed of processing and verbal learning, which were partly accounted for by improvement in the severity of depression symptoms over time.

Identification and treatment of depressive disorders in older adults with cancer

The increasing number of older adults living with cancer will inevitably include vulnerable subgroups who experience a range of depressive symptoms throughout the care continuum. It is well established that depression can lead to decreased quality of life, poor treatment adherence, increased length of hospital stay and health service utilization, and in severe cases, suicide. Thus, clinicians working in oncology must be able to identify, conceptualize, and treat (or connect to services) the mental health concerns of their older patients. This brief review describes the unique etiologies, features, and treatments for depressive syndromes among older adults in the oncology setting, drawing on the literature and prevailing depression management guidelines from both psycho-oncology and geriatric depression research.

Do baseline WAIS-III subtests predict treatment outcomes for depressed inpatients receiving fluoxetine?

This study aimed to determine whether baseline WAIS-III subtests could be associated with treatment outcomes for patients with major depressive disorder (MDD) receiving a 6-week fluoxetine treatment. A total of 131 acutely ill MDD inpatients were enrolled to receive 20 mg of fluoxetine daily for 6 weeks. Eight WAIS-III subtests were administered at baseline. Symptom severity and functional impairment were assessed at baseline, and again at weeks 1, 2, 3, 4, and 6 using the 17-item Hamilton Depression Rating Scale (HAMD-17) and the Modified Work and Social Adjustment Scale (MWSAS), respectively. The generalized estimating equations method was used to analyze the influence of potential predictors over time on the HAMD-17 and MWSAS, after adjusting for covariates. Of the 131 participants, 104 (79.4%) who completed 8 WAIS-III subtests at baseline and had at least one post-baseline assessment were included in the analysis. Patients with lower forward digit span scores were more likely to have poor treatment outcomes, both measured by HAMD-17, and by MWSAS. Forward digit span may be clinically useful in identifying MDD patients with greater treatment difficulty in symptoms and functioning. Other neurocognitive tests to predict treatment outcome require further exploration.

Clinical and radiological characteristics of early versus late mild cognitive impairment in patients with comorbid depressive disorder

OBJECTIVE

The classification of mild cognitive impairment (MCI) continues to be debated though it has recently been subtyped into late (LMCI) versus early (EMCI) stages. Older adults presenting with both a depressive disorder (DEP) and cognitive impairment (CI) represent a unique, understudied population. Our aim was to examine baseline characteristics of DEP-CI patients in the DOTCODE trial, a randomized controlled trial of open antidepressant treatment for 16 weeks followed by add-on donepezil or placebo for 62 weeks.

METHODS/DESIGN

Key inclusion criteria were diagnosis of major depression or dysthymic disorder with Hamilton Depression Rating Scale (HAM-D) score >14, and cognitive impairment defined by MMSE score ≥21 and impaired performance on the WMS-R Logical Memory II test. Patients were classified as EMCI or LMCI based on the 1.5 SD cutoff on tests of verbal memory, and compared on baseline clinical, neuropsychological, and anatomical characteristics.

RESULTS

Seventy-nine DEP-CI patients were recruited of whom 39 met criteria for EMCI and 40 for LMCI. The mean age was 68.9, and mean HAM-D was 23.0. Late mild cognitive impairment patients had significantly worse ADAS-Cog (P < .001), MMSE (P = .004), Block Design (P = .024), Visual Rep II (P = .006), CFL Animal (P = .006), UPSIT (P = .051), as well as smaller right hippocampal volume (P = .037) compared to EMCI patients. MRI indices of cerebrovascular disease did not differ between EMCI and LMCI patients.

CONCLUSIONS

Cognitive and neuronal loss markers differed between EMCI and LMCI among patients with DEP-CI, with LMCI being more likely to have the clinical and neuronal loss markers known to be associated with Alzheimer's disease.

The lack of meaningful association between depression severity measures and neurocognitive performance

BACKGROUND

Neurocognitive deficits are common in depression, but most prior studies have not found strong associations between standard measures of symptom severity and the extent of these neurocognitive deficits. Diagnostic heterogeneity, or the lack of specific questions about neurocognition in these measures, may be undermining these associations.

METHOD

Neuropsychological performance was assessed via 10 tasks in a sample of 262 unmedicated patients with Major Depressive Disorder (MDD) and compared to that in healthy volunteers (n = 140), then correlated with (1) standard measures of depression severity including the Hamilton Depression Rating Scale and Beck Depression Inventory, (2) previously established, factor-analytically derived symptom factors that characterize the heterogeneity of these scales, and (3) a separate measure of cognitive complaint (Cognitive Failures Questionnaire) that was included to address the absence of specific questions about cognition in standard rating scales.

RESULTS

Neurocognitive performance in these unmedicated MDD patients was not significantly associated with either total scores on the depression severity measures, any of their derived symptom factors, or the degree of subjective cognitive complaint - which itself was most strongly associated with mood disturbance.

LIMITATIONS

Depressed patients with the most prominent neurovegetative symptoms may be underrepresented in this sample.

CONCLUSIONS

Neurocognitive deficits were only weakly associated with standard depression symptom ratings, and not captured by self-report ratings of cognitive complaint. Neurocognitive deficits appear to be a separate symptom dimension that cannot be inferred from overall depression severity and require their own assessment, given that they have prognostic value for functional outcomes, suicide risk, and differential therapeutics.

Toward Prevention of Mild Cognitive Impairment in Older Adults With Depression: An Observational Study of Potentially Modifiable Risk Factors

OBJECTIVE

Late-life depression has been associated with increased risk of mild cognitive impairment (MCI) and dementia. Predictors of increased risk are incompletely understood. Identification of potentially modifiable risk factors could facilitate prevention of MCI and dementia. This study aimed to determine which clinical characteristics are associated with increased risk of MCI among older adults with depression and normal cognition at baseline.

METHODS

Data from the National Alzheimer's Coordinating Center dataset were used. Study participants who attended a participating Alzheimer's Disease Center from September 2005 through September 2017 with normal cognition and a history of clinically defined depression (broadly based on DSM criteria) were followed until first diagnosis of MCI (or dementia when MCI was not diagnosed).

RESULTS

A total of 2,655 study participants were followed for a median duration of 41.8 months. Of these, 586 (22.1%) developed either MCI (n = 509, 19.2%) or dementia (n = 77, 2.9%). In survival analyses, cognitive decline was associated with age, sex, education, baseline cognition, and several potentially modifiable risk factors including vascular risk factors, hearing impairment, vitamin B₁₂ deficiency, active depression within the last 2 years, and increased severity of depression. In an adjusted survival analysis, the only variables that remained significantly associated with development of MCI or dementia were female sex (HR = 0.72; 95% CI, 0.59-0.88), higher education (HR = 0.96; 95% CI, 0.93-0.99), and higher baseline cognition (HR = 0.87; 95% CI, 0.82-0.93), which were associated with reduced risk, and older age (HR = 1.07; 95% CI, 1.05-1.08), active depression within the last 2 years (HR = 1.41; 95% CI, 1.15-1.74), and increased severity of depression (HR = 1.05; 95% CI, 1.02-1.09), which were associated with increased risk.

CONCLUSIONS

Development of MCI is associated with several potentially modifiable risk factors in older adults with depression. Future studies should determine whether active management of risk factors could reduce incidence of MCI in this vulnerable population.

Neurocognitive performance predicts treatment outcome with cognitive behavioral therapy for major depressive disorder

The current study examined the contribution of baseline neuropsychological functioning to the prediction of antidepressant outcome with cognitive behavioral therapy (CBT) for Major Depressive Disorder (MDD). We hypothesized that depressed participants who were more neurocognitively intact and had less rigid, negative thinking would respond better to CBT. Thirty-one MDD patients completed a comprehensive neuropsychological battery before initiation of CBT. A subgroup also completed a probabilistic reversal learning task. Depression severity was assessed with the Beck Depression Inventory (BDI); rigid, negative thinking was assessed with the Dysfunctional Attitudes Scale (DAS) and the Automatic Thoughts Questionnaire (ATQ) throughout treatment. Remitters were compared to non-remitters. Paradoxically, eventual remitters performed generally worse across the neuropsychological battery considered as a whole. Univariate testing showed a significant difference on only a single measure, the Continuous Performance Test d', when corrected for multiple comparisons. Baseline rigid, negative thinking did not predict treatment outcome. Results suggest that the structure of CBT may particularly benefit individuals with mild depression-related neurocognitive difficulties during a depressive episode. Further research is needed to examine these patient characteristics and their potential contribution to the mechanisms of CBT efficacy.

Aberrant Default Mode Network Underlying the Cognitive Deficits in the Patients With Late-Onset Depression

Late-onset depression (LOD) is regarded as a risk factor or a prodrome of Alzheimer’s disease (AD). Moreover, LOD patients with cognitive deficits have the higher risk of subsequent AD. Thus, it is necessary to understand the neural underpinnings of cognitive deficits and its pathological implications in LOD. Consistent findings show that the default mode network (DMN) is an important and potentially useful brain network for the cognitive deficits in LOD patients. In recent years, genetics has been actively researched as a possible risk factor in the pathogenesis of LOD. So, in this review, we discuss the current research progress on the cognitive deficits and DMN in LOD through a combined view of brain network and genetics. We find that different structural and functional impairments of the DMN might be involved in the etiological mechanisms of different cognitive impairments in LOD patients.

Current Status of Cognitive Remediation for Psychiatric Disorders: A Review

Cognition is an important factor that affects daily functioning and quality of life. Impairment in cognitive function is a common symptom present in various psychological disorders, which hinders patients from functioning normally. Given that cognitive impairment has devastating effects, enhancing this in patients should lead to improvements in compromised quality of life and functioning, including vocational functioning. Over the past 50 years, several attempts have been made to improve impaired cognition, and empirical evidence for cognitive remediation (CR) has accumulated that supports its efficacy for treating schizophrenia. More recently, CR has been successfully applied in the treatment of depressive disorders, bipolar disorders, attention deficit/hyperactivity disorder, and anorexia nervosa. This study critically reviews recent CR studies and suggests their future direction. This study aimed to provide a modern definition of CR, and examine the current status of empirical evidence and representative CR programs that are widely used around the world.