State of the Science of Neural Systems in Late-Life Depression: Impact on Clinical Presentation and Treatment Outcome

Connectivity patterns of the core resting-state networks associated with apathy in late-life depression

BACKGROUND

Apathy is associated with reduced antidepressant response and dementia in late-life depression (LLD). However, the functional cerebral basis of apathy is understudied in LLD. We investigated the functional connectivity of 5 resting-state networks (RSN) hypothesized to underlie apathy in LLD.

METHODS

Resting-state functional MRI data were collected from individuals with LLD who did not have dementia as well as healthy older adults between October 2019 and April 2022. Apathy was evaluated using the diagnostic criteria for apathy (DCA), the Apathy Evaluation Scale (AES) and the Apathy Motivation Index (AMI). Subnetworks whose connectivity was significantly associated with each apathy measure were identified via the threshold-free network-based statistics. Regions that were consistently associated with apathy across the measures were reported as robust findings.

RESULTS

Our sample included 39 individuals with LLD who did not have dementia and 26 healthy older adults. Compared with healthy controls, individuals with LLD had an altered intra-RSN and inter-RNS connectivity in the default mode, the cingulo-opercular and the frontoparietal networks. All 3 apathy measurements showed associations with modified intra-RSN connectivity in these networks, except for the DCA in the cingulo-opercular network. The AMI scores showed stronger associations with the cingulo-opercular and frontoparietal networks, whereas the AES had stronger associations with the default mode network and the goal-oriented behaviour network.

LIMITATIONS

The study was limited by the small number of participants without apathy according to the DCA, which may have reduced the statistical power of between-group comparisons. Additionally, the reliance on specific apathy measures may have influenced the observed overlap in brain regions.

CONCLUSION

Our findings indicate that apathy in LLD is consistently associated with changes in both intra-RSN and inter-RSN connectivity of brain regions implicated in goal-oriented behaviours. These results corroborate previous findings of altered functional RSN connectivity in severe LLD.

Executive function deficits and medial temporal lobe atrophy in late-life depression and Alzheimer's disease: a comparative study

Objectives

Alzheimer's disease (AD) and late-life depression (LLD) frequently exhibit executive function deficits (EFD) and medial temporal lobe atrophy (MTA) as shared characteristics. The objective of this research was to examine the utility of the Trail Making Test (TMT) and the MTA scale in distinguishing between LLD and AD.

Methods

A study of 100 patients, 50 with AD and 50 with LLD, was conducted using a cross-sectional design. The individuals were subjected to clinical evaluations to assess their level of depression and overall cognitive abilities, which included the Geriatric Depression Scale (GDS), Mini-Mental State Examination (MMSE), and Montreal Cognitive Assessment (MoCA). We evaluated executive function deficits (EFD) through the use of the TMT, which includes both TMT-A and TMT-B. MTA was measured using magnetic resonance imaging. To evaluate the ability of TMT and MTA scale to distinguish between the two groups, a receiver operating characteristic (ROC) curve was utilized. To investigate the connections between MTA and neuropsychological measures, a correlation analysis was performed.

Results

AD patients exhibited notably reduced MMSE, MoCA, and GDS scores, as well as an increased MTA total scores, time spent on TMT-A, and TMT-B compared to LLD patients (p < 0.05). TMT-A and TMT-B both exhibited excellent discriminatory power between AD and LLD, achieving area under curve (AUC) values of 92.2 and 94.2%, respectively. In AD patients, there was a negative correlation between MMSE and MoCA scores and MTA scores, while in LLD patients, there was a positive correlation between time spent on TMT-A and GDS scores and MTA scores.

Conclusion

AD patients experience more severe EFD and MTA than LLD patients. The differential diagnosis of AD and LLD can be aided by the useful tool known as TMT. It is important to acknowledge that TMT is capable of capturing only a fraction of the executive function, thus necessitating a cautious interpretation of research findings.

The Effect of Meditation-Based Interventions on Patients with Fatigue Symptoms: A Systematic Review and Meta-Analysis

Persistent fatigue constitutes a prevalent and debilitating symptom in several diseases. The symptom is not effectively alleviated by pharmaceutical treatments, and meditation has been proposed as a non-pharmacological intervention. Indeed, meditation has been shown to reduce inflammatory/immune problems, pain, stress, anxiety and depression which are associated with pathological fatigue. This review synthesizes data from randomized control trials (RCTs) that explored the effect of meditation-based interventions (MeBIs) on fatigue in pathological conditions. Eight databases were searched from inception to April 2020. Thirty-four RCTs met eligibility criteria and covered six conditions (68% cancer), 32 of which were included in the meta-analysis. The main analysis showed an effect in favor of MeBIs compared to control groups (g = 0.62). Separate moderator analyses assessing control group, pathological condition, and MeBI type, highlighted a significantly moderating role of the control group. Indeed, compared to actively controlled studies, studies using a passive control group were associated with a statistically significantly more beneficial impact of the MeBIs (g = 0.83). These results indicate that MeBIs alleviate pathological fatigue and it seems that the studies with a passive control group showed a greater effect of MeBI on the reduction of fatigue compared to studies using active control groups. However, the specific effect of meditation type and pathological condition should be analyzed with more studies, and there remains a need to assess meditation effects on different types of fatigue (i.e., physical and mental) and in additional conditions (e.g., post-COVID-19).

Treatment-Resistant Late-Life Depression: A Review of Clinical Features, Neuropsychology, Neurobiology, and Treatment

Major depression is common in older adults (≥ 60 years of age), termed late-life depression (LLD). Up to 30% of these patients will have treatment-resistant late-life depression (TRLLD), defined as depression that persists despite two adequate antidepressant trials. TRLLD is challenging for clinicians, given several etiological factors (eg, neurocognitive conditions, medical comorbidities, anxiety, and sleep disruption). Proper assessment and management is critical, as individuals with TRLLD often present in medical settings and suffer from cognitive decline and other marks of accelerated aging. This article serves as an evidence-based guide for medical practitioners who encounter TRLLD in their practice.

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.

[Platelet glutathione reductase and glutathione-S-transferase in elderly patients with depression]

OBJECTIVE

To compare the activity of platelet glutathione reductase (GR) and glutathione-S-transferase (GST) in elderly patients with depression and in the control group, and to identify a possible relationship between the activity of these enzymes and clinical parameters of the disease.

MATERIAL AND METHODS

We examined 42 elderly patients (60-86 years old) with depressive episodes of various nosological categories according to ICD-10: a single depressive episode (F32.0, F32.1), a depressive episode in recurrent depressive disorder (RDR - F33.0, F33.1), and a depressive episode in bipolar disorder (BD - F31.3). The GR, GST activity and the severity of depression were assessed twice: before the beginning of the course of 28-day antidepressant therapy (day 0) and on the 28th day of the course of therapy, using the Hamilton Depressive Scale (HAMD-17) and the Hamilton Anxiety Scale (HARS).

RESULTS

As compared with the control group, a significant decrease in GST activity was found in patients before and after the course of therapy (p<0.0001 and p<0.0003, respectively), no significant difference in GR activity was found. Significant correlations of the platelet GR activity in patients before thetreatment course with the age of disease manifestation (R= -0.44; p=0.004, inverse correlation) and with its duration (R=0.43, p=0.004, direct correlation), estimated after a 28-day course of therapy. A significant inverse correlation of the baseline (before treatment) GR activity with the HAMD score estimated after the course of therapy (R=-0.440; p=0.009) was found only in women subgroup (n=33).

CONCLUSION

A pilot study has revealed a decrease in platelet GST activity, and a link between platelet GR activity and the severity of depression after a course of therapy. The results obtained indicate the promise of further study of glutathione metabolism enzymes as a biomarker for assessing the state.

Modifiable predictors of nonresponse to psychotherapies for late-life depression with executive dysfunction: a machine learning approach

The study aimed to: (1) Identify distinct trajectories of change in depressive symptoms by mid-treatment during psychotherapy for late-life depression with executive dysfunction; (2) examine if nonresponse by mid-treatment predicted poor response at treatment end; and (3) identify baseline characteristics predicting an early nonresponse trajectory by mid-treatment. A sample of 221 adults 60 years and older with major depression and executive dysfunction were randomized to 12 weeks of either problem-solving therapy or supportive therapy. We used Latent Growth Mixture Models (LGMM) to detect subgroups with distinct trajectories of change in depression by mid-treatment (6th week). We conducted regression analyses with LGMM subgroups as predictors of response at treatment end. We used random forest machine learning algorithms to identify baseline predictors of LGMM trajectories. We found that ~77.5% of participants had a declining trajectory of depression in weeks 0-6, while the remaining 22.5% had a persisting depression trajectory, with no treatment differences. The LGMM trajectories predicted remission and response at treatment end. A random forests model with high prediction accuracy (80%) showed that the strongest modifiable predictors of the persisting depression trajectory were low perceived social support, followed by high neuroticism, low treatment expectancy, and low perception of the therapist as accepting. Our results suggest that modifiable risk factors of early nonresponse to psychotherapy can be identified at the outset of treatment and addressed with targeted personalized interventions. Therapists may focus on increasing meaningful social interactions, addressing concerns related to treatment benefits, and creating a positive working relationship.

Mechanisms and Treatment of Late-Life Depression

(Appeared originally in Translational Psychiatry 2019; 9:188).

Preliminary Comparison of Subcortical Structures in Elderly Subclinical Depression: Structural Analysis with 3T MRI

Depression in the elderly population has shown increased likelihood of neurological disorders due to structural changes in the subcortical area. However, further investigation into depression related subcortical changes is needed due to mismatches in structural analysis results between studies as well as scarcities in research regarding subcortical connectivity patterns of subclinical depression populations. This study aims to investigate structural differences in subcortical regions of aged participants with subclinical depression using 3Tesla MRI. In structural analysis, volumes of each subcortical region were measured to observe the volumetric difference and asymmetry between groups, but no significant difference was found. In addition, fractional anisotropy (FA) and apparent diffusion coefficient (ADC) did not show any significant differences between groups. Structural analysis using probabilistic tractography indicated that the connection strength between left nucleus accumbens-right hippocampus, and right thalamus-right caudate was higher in the control group than the subclinical depression group. The differences in subcortical connection strength of subclinical depression groups, have shown to correlate with emotional and cognitive disorders, such as anxiety and memory impairment. We believe that the analysis of structural differences and cross-regional network measures in subcortical structures can help identify neurophysiological changes occurring in subclinical depression.

The Age Limit Does Not Exist: A Pilot Usability Assessment of a SMS-Messaging and Smartwatch-Based Intervention for Older Adults with Depression

Current treatments for major depressive disorder are either less effective for older adults (i.e. pharmacotherapy) or are challenging to extend to community settings (i.e. psychotherapy). To improve and extend mental health treatment for older adults, our team has expanded a previously developed streamlined talk-therapy model to incorporate a technology package that includes patient-reported outcome questions (sent via SMS) and a smartwatch. The goal of this pilot study was to assess and improve the usability, usefulness, and acceptability of the technology package. We completed a pilot feasibility and usability assessment with 15 older adults. Participants demonstrated the feasibility of use of the intervention, successfully completing 99% of their assigned tasks during the pilot. Findings were used to address usability barriers in preparation for future clinical trials. Our results highlight the importance completing usability assessment and involving older adults in the intervention design process when incorporating technology into care.

The Role of Exercise in Management of Mental Health Disorders: An Integrative Review

A large and growing body of evidence suggests that physical activity (PA) may hold therapeutic promise in the management of mental health disorders. Most evidence linking PA to mental health outcomes has focused on the effects of aerobic exercise training on depression, although a growing body of work supports the efficacy of both aerobic and resistance exercise paradigms in the treatment of anxiety and post-traumatic stress disorder. Despite abundant evidence linking PA and mental health, use of exercise training as a mental health treatment remains limited due to three important sources of uncertainty: (a) large individual differences in response to exercise treatment within multiple mental health domains; (b) the critical importance of sustained PA engagement, not always achieved, for therapeutic benefit; and (c) disagreement regarding the relative importance of putative therapeutic mechanisms. Our review of treatment data on exercise interventions and mental health outcomes focuses primarily on depression and anxiety within a health neuroscience framework. Within this conceptual framework, neurobiological and behavioral mechanisms may have additiveor synergistic influences on key cognitive and behavioral processes that influence mental health outcomes. We therefore highlight sources of treatment heterogeneity by integrating the critical influences of (a) neurobiological mechanisms enhancing neuroplasticity and (b) behavioral learning of self-regulatory skills. Understanding the interrelationships between dynamic neurobiological and behavioral mechanisms may help inform personalized mental health treatments and clarify why, and for whom, exercise improves mental health outcomes. The review concludes with recommendations for future studies leveraging individual differences to refine treatment approaches to optimize mental health benefits.

Advances in geropsychiatric nursing: A decade in review

This article provides a brief overview of the early development of geropsychiatric nursing (GPN) as background for examining its advancement subsequent to the 2010 Future of Nursing (FON) Report. The FON's education, practice and leadership recommendations form the three pillars that have supported geropsychiatric nursing's continuing evolution, framed within a practice and policy perspective. Lessons learned are relevant to developing the next phase of FON recommendations. The importance of overcoming challenges faced by the field of GPN is supported by the aging global population, the directions of nursing as a discipline, and the clear necessity of an intra- and inter-professional approach to mental health and aging.

Mechanisms and treatment of late-life depression

Depression predisposes to medical illnesses and advances biological aging indicated by shorter telomere length, accelerated brain aging and advanced epigenetic aging. Medical illnesses also increase the risk of late-life depression. The reciprocal relationships of depression with aging-related and disease-related processes have generated pathogenetic hypotheses and provided treatment targets. Targeting risk factors of vascular disease in mid-life is a logical approach in prevention of vascular depression. The depression-executive dysfunction and the vascular depression syndromes have clinical presentations and neuroimaging findings consistent with frontostriatal abnormalities. Dopamine D_2/3 agonists are effective in depression of Parkinson's disease and their efficacy needs to be assessed in these two syndromes. Computerized cognitive remediation targeting functions of the cognitive control network may improve both executive functions and depressive symptoms of late-life major depression. Significant progress has been made in neurostimulation treatments in depressed younger adults. TMS targeting deep structures responsible for mood regulation is well tolerated by older adults and its efficacy in syndromes of late-life depression needs to be studied. Efficacious psychotherapies for late-life depression exist, but are underutilized in part because of their complexity. Streamlined, stepped psychotherapies targeting behaviors assumed to result from dysfunction of brain networks implicated in late-life depression can be easy to learn and have potential for dissemination. However, their effectiveness needs further investigation. Depression increases the risk of dementing disorders. Antidepressants are rather ineffective in treating depression of demented patients, but long-term use of antidepressants may reduce the risk of dementia. However, confirmation studies are needed.