Mechanisms and treatment of late-life depression

Longitudinal associations between late-life depression, cerebrovascular disease and cognition

BACKGROUND

Depression and vascular disease can both be risk factors for cognitive decline. This study assessed whether indicators of vascular disease are associated with depression over time, and whether depression is associated with cognition independent of vascular disease.

METHODS

Participants were 1032 community-dwelling, older adults from the Sydney Memory and Ageing Study. Depressive symptoms were measured on the 15-item Geriatric Depression Scale, and depression trajectories were classified using latent class growth modelling. Global cognition and individual cognitive domains were assessed. Indicators of vascular disease were history of stroke or transient ischaemic attack (TIA) and total white matter hyperintensities (TWMH). Generalised linear mixed modelling assessed whether vascular markers were associated with change in depressive symptoms over time. Linear mixed modelling examined relationships between depression, vascular disease indicators, and cognition.

RESULTS

History of stroke/TIA or TWMH did not predict depression over time (p = 0.11 and p = 0.70). Baseline stroke/TIA history was associated with a decline in attention over time (b = -0.05, p = 0.04). Significant differences between latent depression trajectories classes in cognitive decline were observed, with participants who became depressed over time experiencing decline in global cognition (b = -0.04, p < 0.001), attention (b = -0.05, p < 0.001) and executive function (b = -0.05, p < 0.001), compared to the non-depressed group.

CONCLUSION

Our findings suggest that depression in later life may not precede cognitive decline. Instead, depressive symptoms and cognitive decline, particularly in attention and executive function, may evolve in tandem over time. This reinforces the importance of early identification and treatment of depression in older adults to potentially mitigate cognitive deterioration.

Psychosocial and cognitive determinants of 10-year depressive symptom trajectories in patients with cardiovascular disease: The SMART-Medea Study

BACKGROUND

Middle-aged and older adults presenting clinically relevant depressive symptoms are often undiagnosed. Understanding the determinants of late-life depressive symptoms could improve prognosis. Further, individuals with manifest cardiovascular disease (CVD) are at an increased risk of depression. This study investigated if psychosocial and cognitive factors are associated with depressive symptom trajectories in individuals with CVD.

METHODS

Longitudinal data from the SMART-Medea study of 752 participants (median age 62 years, women 18 %) with a history of CVD was used. Psychosocial determinants (i.e., history of depression, anxiety, neuroticism, locus of control, adverse childhood events, recent adverse events, social support, and somatization) and cognition (i.e., memory functioning, working memory, executive functioning, and processing speed) were assessed via multinomial logistic regressions with depressive symptoms trajectories as outcome (i.e., "never depressed" (reference), "energy/sleep difficulties", "mild depressive symptoms" and "fluctuating severe depression"). Depressive symptom trajectories were based off of longitudinal PHQ-9 scores and created using latent class analysis. Analyses were adjusted for age, sex/gender, and education.

RESULTS

All psychosocial factors were associated with depressive symptom trajectories, except for social support, with increasing associations from the "energy/sleep difficulties" to the "fluctuating severe depression". For cognitive factors, only memory functioning was associated with decreased odds of "fluctuating severe depression" (OR = 0.63, 95 % CI = 0.47-0.85).

LIMITATIONS

The study population consisted of mostly white male participants with CVD; thus, the generalizability to other populations is low.

CONCLUSIONS

Our findings emphasize that a wide range of psychosocial factors are associated with mild as well as severe trajectories of depressive symptoms in patients with manifest CVD. Focusing on psychosocial factors could improve one's prognosis of depressive symptomology.

Prevalence of depressive symptoms in people aged 50 years and older: A retrospective cross-sectional study

BACKGROUND

Depression is a serious health problem worldwide and is often associated with disability and reduced quality of life. In aging societies, early recognition of depression in older adults is highly relevant. Therefore, this study investigated the prevalence of depressive symptoms in individuals aged 50 and older with the aim to identify those at risk for major depression.

METHODS

We performed a retrospective cross-sectional study with data from 1000BRAINS to assess depressive symptoms in a sample of 1017 healthy adults aged 50 and older. The prevalence and dimension of depressive symptoms were measured by the Beck Depression Inventory II, and differences between demographic, clinical, and lifestyle-associated variables and the prevalence of depressive symptoms were analyzed.

RESULTS

Depressive symptoms were present in 21.3 % of the participants and were minimal in 14.2 %, mild in 4.5 %, moderate in 1.8 %, and severe in 0.8 %. The prevalence of depressive symptoms was highest in the age group 50 to 59 years, and the prevalence of severe depressive symptoms decreased with increasing age. A positive family history of depression, cognitive impairment, medication intake, and polyneuropathy were associated with significantly higher levels of depressive symptoms.

LIMITATIONS

The retrospective cross-sectional design and evaluation of depressive symptoms by a self-rating instrument may limit the generalizability of the results.

CONCLUSION

This study supports earlier findings of a higher prevalence of depressive symptoms among older adults. The group aged 50 to 59 appears to be particularly affected. Additionally, poor physical health, greater cognitive impairment, and sex-specific factors appear to contribute to depressive symptomatology.

Depressive Symptoms and Amyloid Pathology

Importance

Depressive symptoms are associated with cognitive decline in older individuals. Uncertainty about underlying mechanisms hampers diagnostic and therapeutic efforts. This large-scale study aimed to elucidate the association between depressive symptoms and amyloid pathology.

Objective

To examine the association between depressive symptoms and amyloid pathology and its dependency on age, sex, education, and APOE genotype in older individuals without dementia.

Design, Setting, and Participants

Cross-sectional analyses were performed using data from the Amyloid Biomarker Study data pooling initiative. Data from 49 research, population-based, and memory clinic studies were pooled and harmonized. The Amyloid Biomarker Study has been collecting data since 2012 and data collection is ongoing. At the time of analysis, 95 centers were included in the Amyloid Biomarker Study. The study included 9746 individuals with normal cognition (NC) and 3023 participants with mild cognitive impairment (MCI) aged between 34 and 100 years for whom data on amyloid biomarkers, presence of depressive symptoms, and age were available. Data were analyzed from December 2022 to February 2024.

Main Outcomes and Measures

Amyloid-β1-42 levels in cerebrospinal fluid or amyloid positron emission tomography scans were used to determine presence or absence of amyloid pathology. Presence of depressive symptoms was determined on the basis of validated depression rating scale scores, evidence of a current clinical diagnosis of depression, or self-reported depressive symptoms.

Results

In individuals with NC (mean [SD] age, 68.6 [8.9] years; 5664 [58.2%] female; 3002 [34.0%] APOE ε4 carriers; 937 [9.6%] had depressive symptoms; 2648 [27.2%] had amyloid pathology), the presence of depressive symptoms was not associated with amyloid pathology (odds ratio [OR], 1.13; 95% CI, 0.90-1.40; P = .29). In individuals with MCI (mean [SD] age, 70.2 [8.7] years; 1481 [49.0%] female; 1046 [44.8%] APOE ε4 carriers; 824 [27.3%] had depressive symptoms; 1668 [55.8%] had amyloid pathology), the presence of depressive symptoms was associated with a lower likelihood of amyloid pathology (OR, 0.73; 95% CI 0.61-0.89; P = .001). When considering subgroup effects, in individuals with NC, the presence of depressive symptoms was associated with a higher frequency of amyloid pathology in APOE ε4 noncarriers (mean difference, 5.0%; 95% CI 1.0-9.0; P = .02) but not in APOE ε4 carriers. This was not the case in individuals with MCI.

Conclusions and Relevance

Depressive symptoms were not consistently associated with a higher frequency of amyloid pathology in participants with NC and were associated with a lower likelihood of amyloid pathology in participants with MCI. These findings were not influenced by age, sex, or education level. Mechanisms other than amyloid accumulation may commonly underlie depressive symptoms in late life.

Molecular hydrogen inhibits neuroinflammation and ameliorates depressive-like behaviors and short-term cognitive impairment in senescence-accelerated mouse prone 8 mice

BACKGROUND AND AIMS

Neuroinflammation, a low-grade chronic inflammation of the central nervous system, is linked to age-related neuropsychiatric disorders such as senile depression and Alzheimer's disease. Recent studies have explored controlling neuroinflammation as a novel treatment strategy. Molecular hydrogen shows anti-inflammatory effects. However, its impacts on neuroinflammation and age-related neuropsychiatric disorders remain unelucidated. We investigated molecular hydrogen's effects on microglial activation, neuroinflammation, depressive-like behavior, and short-term cognitive decline in senescence-accelerated mouse-prone 8 (SAMP8) mice.

METHODS

Six-week-old SAMP8 or senescence-accelerated mouse-resistant 1 (SAMR1) mice received hydrogen-rich jelly (HRJ) or placebo jelly (PJ) from six weeks of age for 26-28 weeks. Depressive-like behavior was assessed using tail suspension and forced swimming tests, while cognitive function was evaluated using the Y-maze and object recognition tests. Brain tissues were used for immunohistochemical studies or to measure pro-inflammatory cytokine levels via enzyme-linked immunosorbent assay (ELISA).

RESULTS

HRJ intake reduced immobility time in both tail suspension and forced swimming tests and enhanced visual cognitive and spatial working memory in SAMP8 mice. Additionally, HRJ intake suppressed the 8-hydroxy-2'-deoxyguanosine (8-OHdG), Iba1, and cleaved caspase 3 expression levels in the medial prefrontal cortex and hippocampal dentate gyrus. Furthermore, HRJ intake significantly lowered IL-6 levels in brain tissues of SAMP8 mice.

CONCLUSIONS

These findings suggest that molecular hydrogen treatment may regulate neuroinflammation induced by activated microglia and improve depressive-like behavior and short-term cognitive impairment in SAMP8 mice.

The potential of depressive symptoms to identify cognitive impairment in ageing

Depressive symptoms are common in mild cognitive impairment (MCI), dementia caused by Alzheimer's disease (AD dementia) and in cognitively unimpaired older adults. However, it is unclear whether they could contribute to the identification of cognitive impairment in ageing. To assess the potential utility of depressive symptoms to distinguish between healthy cognitive ageing and MCI and AD dementia. The diagnostic workup of the cognitive function of 1737 older cognitively unimpaired individuals, 334 people with MCI and 142 individuals with AD dementia relied on a comprehensive neuropsychiatric assessment, including the Mini Mental State Examination (MMSE). Depressive symptoms were tapped with the 15-item Geriatric Depression Scale (GDS). Proportional odds logistic regression (POLR) models and the machine learning technique Adaptive Boosting algorithm (AdaBoost) were employed. Stratified repeated random subsampling (stratified bootstrap resampling) was used to recursive partitioning to training- and validation set (70/30 ratio). The average accuracy of the POLR models for the GDS total score in distinguishing between cognitive impairment and healthy cognitive ageing exceeded 78% and was inferior to that of MMSE. Of note, the sensitivity of GDS total score was very low. By employing the AdaBoost algorithm and considering GDS items separately, the average accuracy was higher than 0.72 and comparable to that of the MMSE, while sensitivity- and specificity values were more balanced. The findings of the study provide initial evidence that depressive symptoms may contribute to distinguishing between cognitive impairment and cognitively healthy ageing.

Data-driven subtypes of late-life depression-secondary analysis of a cluster-randomized RCT

OBJECTIVES

Cognitive performance varies among depressed older patients and is known to affect treatment outcome. We used a data-driven approach to create subtypes of late-life depression and exploratively visualized the course of depression during either behavioural activation (BA) or treatment as usual (TAU).

METHOD

Among 161 depressed (PHQ ≥ 10) older (≥65 years) participants of a cluster randomized controlled trial in primary care (NL5436), we performed latent class analysis (LCA) on individual depressive symptoms and performance on several cognitive tests. The course of depressive symptoms during treatment was plotted to explore whether differences between the classes differed between BA and TAU.

RESULTS

Five classes best fitted the data: (1) mild depression without cognitive deficits, (2) moderate depression with insomnia and cognitive deficits, (3) severe depression with cognitive deficits, (4) moderately severe depression with hypersomnia and cognitive deficits, and (5) moderately severe depression with cognitive-affective symptoms but no cognitive deficits. Graphs showed that depressive symptoms of subgroups with severe depressive symptoms improved more during BA compared to TAU, regardless of cognitive deficits.

CONCLUSIONS

We identified five subgroups. Graphs suggest that effectiveness of BA is similar across all subgroups, whereas TAU seems less effective in the more severely depressed subgroups. Replication is warranted.

Psychophysiological indices of late-life depression: A systematic review

BACKGROUND

Major depression in the older population has a profound impact on patients' quality of life and is associated with an increased risk of developing several medical illnesses. Psychophysiological methods, such as electroencephalography (EEG), functional near-infrared spectroscopy (fNIRS), and eye-tracking, have provided evidence of physiological changes associated with depression in adult life. However, these aspects have not been thoroughly investigated during late-life (over 60 years of age).

METHODS

A systematic review of the scientific literature covering the studies published between 1990 and 2022 was performed to describe the current evidence on easily attainable psychophysiological factors (detected by EEG, fNIRS and eye-tracking) associated with depression in late-life.

RESULTS

Twelve studies were included in the systematic review. The included studies showed some consistent physiological patterns associated with late-life depression, such as brain hypoactivation in frontal and temporal areas and attentional biases toward emotional stimuli. No reliable patterns in EEG asymmetry and power spectrum were found, in contrast to studies on early-life depression.

LIMITATIONS

The small number of available studies, together with the heterogeneity in the techniques and methods used, highlight the need for further research to reliably identify the psychophysiological aspects of depression in late-life.

CONCLUSIONS

Physiological indices of late-life depression, as assessed by EEG, fNIRS and eye-tracking, may differ from those of early-life. The study of these indices could better clarify the physiological mechanisms underlying late-life depression with possible clinical and research implications. Recommendations for future research are also discussed.

Cognitive reserve types and depressive symptoms development in late-life: A population-based cohort study

INTRODUCTION

Cognitive reserve (CR) describes individual differences in susceptibility to brain damage that translates into varying dementia onsets and may also influence the occurrence of depressive symptoms. Within a population-based cohort of older people, we investigated two operationalizations of CR, residual- and activity-based approaches, in their association with the development of depressive symptoms.

METHODS

We analyzed longitudinal data on 402 dementia- and depression-free adults aged 60+ from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K) who underwent brain MRI at baseline. Residual-based reserve was derived by regressing episodic memory on a brain-integrity index incorporating six structural MRI markers. Activity-based reserve factored lifelong CR-enhancing experiences, including education, work complexity, social network, and leisure activities. Clinically relevant depressive symptoms were defined as a Montgomery-Åsberg Depression Rating Scale score >6. Cox hazard models were used to explore the association between both residual- and activity-based CR measures (categorized in tertiles) and incidence of depressive symptoms over a 15-year follow-up, while accounting for sociodemographic, clinical, behavioral factors, and brain integrity. Analyses for the activity-based measure were replicated in the full SNAC-K sample (N = 2709), further exploring depression diagnosis as additional outcome.

RESULTS

Compared to low levels, higher levels of residual-based CR were associated with a lower hazard of depressive symptom onset in fully adjusted models (HR: .43, 95%CI .22, .84). While activity-based CR was not significantly associated with developing depressive symptoms in the MRI subsample (HRhigh .47, 95%CI .21, 1.04), it was in the full sample (HRhigh .52, 95%CI .39, .71). Activity-based CR was further associated with depression diagnoses in the full sample (HRhigh: .45, 95%CI .31, .65).

DISCUSSION

Largely independent of its measurement, CR appears to influence depressive symptomatology in late life. Reserve-enhancing initiatives may be beneficial not only for cognitive but also for mental health in older people.

The trajectories of depression and multimorbidity affect the patterns of cognitive decline: a prospective cohort study

BACKGROUND

The course of decline of global cognitive function is heterogeneous, with patterns varying among individuals. The influence of depression, functional limitations and multimorbidity on patterns of decline of global cognitive function among community-dwelling older adults remains unknown. This study examines the relationship between these health conditions and the course of decline of global cognitive function.

METHODS

A prospective cohort of 4032 participants aged ≥60 years at baseline was constructed using the Health and Retirement Study (2006-20), through surveys every 2 years. Information on depression, functional limitations and multimorbidity was collected from 2006 to 2012. Data on cognitive function were collected between 2012 and 2020. Latent class trajectory models were used to identify the latent trajectories. Multinomial logistic regression models were employed to analyse the association between the latent trajectories and cognitive function.

RESULTS

Different trajectories were identified for depression (low-stable, decline-rise and rise-decline), activities of daily living (ADLs; low-stable, decline-rise and rise-decline), instrumental activities of daily living (IADLs; low-stable and rise), and multimorbidity (stable and rise). Three trajectories of cognitive decline were identified: high stable, modest and later steep. The trajectories of depression (for decline-rise: OR: 1.47, 95% CI: 1.11-1.95; for rise-decline: OR: 1.72, 95% CI: 1.24-2.38) and multimorbidity (OR: 1.63, 95% CI: 1.08-2.46) increased the risk of cognitive decline.

CONCLUSION

The trajectories of depression and multimorbidity affect cognitive decline patterns. Longitudinal surveillance of health conditions can be used to identify different patterns of cognitive decline and predict faster cognitive decline.

Network models of late life depression symptoms and cognitive impairments across time

OBJECTIVES

Prevalence of late life depression symptoms is estimated to be up to 29%. For older adults, depression symptoms can constitute both a risk and outcome for cognitive impairment. Understanding how specific depression symptoms and cognitive impairment domains interact over time in older adults is key for prevention, early identification, and treatment.

METHOD

Using cross-sectional psychometric network models, this study aimed to explore interactions between late-life depression symptoms and cognitive impairment domains across different time points using data from waves 7-9 of the English Longitudinal Study of Ageing (ELSA).

RESULTS

Across 3544 participants, ≥65 years of age, with no diagnosed dementia-related disorders, the depression symptom everything was an effort showed high expected influence across all time points. Across two time points, object naming and verbal fluency also showed high expected influence. Self-reported memory demonstrated high bridge centrality connecting depression symptom and cognitive impairment domains. Network centralities differed significantly across time points.

CONCLUSION

For older adults, fatigue appears a key depression symptom. Cognitive impairment domains become more influential over time, and perceived memory loss links cognitive impairment to depression symptoms. Practical implications are discussed in relation to targeting depression symptoms and cognitive impairment domains.

Improved outcomes for depressed elder abuse victims with video-delivered psychotherapy during COVID-19

OBJECTIVE

There is a lack of evidence-based scalable therapies for elder abuse victims, with no current remotely delivered tailored psychotherapy. The purpose of this manuscript is to (a) examine the effectiveness of a brief therapy for depression for elder abuse victims, and (b) to compare remote intervention delivery via phone or video to the traditional in-person delivery.

METHOD

PROTECT, Providing Options to Elderly Clients Together, is a brief therapy developed in collaboration with partners at the Department for the Aging (DFTA) of New York City. During the COVID-19 outbreak, PROTECT delivery shifted from in-person to phone or video delivery. Depression severity was tracked using the Patient Health Questionaire-9 (PHQ-9). Reduction in depression severity was evaluated using a linear mixed effects model with non-inferiority test to compare the effectiveness of video vs in-person delivery of PROTECT.

RESULTS

PROTECT reduced depression (average 5.15 PHQ-9 points). Video and phone delivery were non-inferior to in-person delivery. The video group completed therapy more quickly than the in-person group and had a more rapid improvement in depression symptoms.

CONCLUSIONS

PROTECT therapy delivered remotely reduces depression among diverse elder abuse victims. Video delivery of PROTECT could increase reach and scalability to serve more vulnerable older depressed victims.

Bidirectional relationship between epigenetic age and stroke, dementia, and late-life depression

Chronological age is an imperfect estimate of molecular aging. Epigenetic age, derived from DNA methylation data, provides a more nuanced representation of aging-related biological processes. We examine the bidirectional relationship between epigenetic age and brain health events (stroke, dementia, late-life depression) using data from 4,018 participants. Participants with a prior brain health event are 4% epigenetically older (β = 0.04, SE = 0.01), indicating these conditions are associated with accelerated aging beyond that captured by chronological age. Additionally, a one standard deviation increase in epigenetic age is associated with 70% higher odds of experiencing a brain health event in the next four years (OR = 1.70, 95% CI = 1.16-2.50), suggesting epigenetic age acceleration is not just a consequence but also a predictor of poor brain health. Mendelian Randomization analyses replicate these findings, supporting their causal nature. Our results support using epigenetic age as a biomarker to evaluate interventions aimed at preventing and promoting recovery after brain health events.

Transcranial Doppler sonography follow-up study in mild vascular cognitive impairment

BACKGROUND

To date, few data to transcranial Doppler sonography (TCD) are available in patients with mild vascular cognitive impairment (VCI) at risk for vascular or mixed dementia. In a previous study in patients with mild VCI and cerebral small vessels disease, a hemodynamic pattern of cerebral hypoperfusion and enhanced vascular resistance were observed; however, longitudinal data are currently lacking. Here, we perform a clinical, psychopathological, and neurosonological follow-up of patients with VCI in order to monitor any progression and to identify TCD measures to detect it.

METHODS

From the original cohort of 161 patients, 127 with VCI (mean age 73.6 ± 7.1; 67 males) were re-evaluated after 5.0 ± 1.8 years. Namely, the Montreal Cognitive Assessment (MoCA), the 17-items Hamilton Depression Rating Scale (HDRS), and the Stroop Color-Word Interference Test (StroopT) were administered to screen for global cognitive status, to quantify depressive symptoms, and to explore executive functions, respectively. Mean blood flow velocity (MBFV), peak systolic blood flow velocity (PSV), end-diastolic blood flow velocity (EDV), pulsatility index (PI), and resistivity index (RI) were recorded from the middle cerebral artery, bilaterally.

RESULTS

At follow up, patients exhibited a significant worsening of both MoCA (21.7 ± 2.1 vs. 20.7 ± 2.0) and StroopT scores (57.4 ± 19.4 vs. 59.7 ± 18.6), whereas HDRS showed an improvement, although the mean raw score remained above the cut-off value for depression (10.3 ± 6.6 vs. 9.8 ± 6.3). MBFV, PSV, and EDV showed a significant increase in PSV and PI and a reduction in EDV. When focused to younger patients (<65 years), we confirmed the significant worsening of both MoCA and StroopT but not HDRS, as well as the significant changes in PI and RI. Finally, considering the differences (D) between baseline and follow-up, the following significant correlations emerged, although with a small-to-medium effect size for all of them: positive correlation between MBFV-D and MoCA-D and between RI-D and STROOP-D, and a negative significant correlation between RI-D and MoCA-D.

CONCLUSIONS

Notwithstanding some limitations, such as the lack of a control group and neuroimaging data at follow-up, TCD may contribute to the early detection, monitoring, and management of VCI patients at risk for dementia. Together with compatible clinical and cognitive features, the exploration of early TCD markers that possibly indicate a higher risk of progression might represent an intriguing research direction and a significant clinical perspective.

Disrupted microsaccade responses in late-life depression

Late-life depression (LLD) is a psychiatric disorder in older adults, characterized by high prevalence and significant mortality rates. Thus, it is imperative to develop objective and cost-effective methods for detecting LLD. Individuals with depression often exhibit disrupted levels of arousal, and microsaccades, as a type of fixational eye movement that can be measured non-invasively, are known to be modulated by arousal. This makes microsaccades a promising candidate as biomarkers for LLD. In this study, we used a high-resolution, video-based eye-tracker to examine microsaccade behavior in a visual fixation task between LLD patients and age-matched healthy controls (CTRL). Our goal was to determine whether microsaccade responses are disrupted in LLD compared to CTRL. LLD patients exhibited significantly higher microsaccade peak velocities and larger amplitudes compared to CTRL. Although microsaccade rates were lower in LLD than in CTRL, these differences were not statistically significant. Additionally, while both groups displayed microsaccadic inhibition and rebound in response to changes in background luminance, this modulation was significantly blunted in LLD patients, suggesting dysfunction in the neural circuits responsible for microsaccade generation. Together, these findings, for the first time, demonstrate significant alterations in microsaccade behavior in LLD patients compared to CTRL, highlighting the potential of these disrupted responses as behavioral biomarkers for identifying individuals at risk for LLD.

Depressive symptoms are linked to age-specific neuroanatomical and cognitive variations

Depression is a heterogeneous disorder, both in terms of patient symptomatology and in patient sociodemographic factors. Here, we examine the contribution of age to this heterogeneity, by characterizing the associations of depressive symptoms with cognitive performance and brain structure across the lifespan. We analyzed data from the Cambridge Centre for Aging Neuroscience (Cam-CAN) cohort (N = 2591, age 18-99). A subset of this cohort (N = 647) underwent structural MRI. Depressive symptoms were measured using the Hospital Anxiety and Depression Scale. Cognitive assessments were performed using The Addenbrooke's Cognitive Examination Revised. Generalized linear models were employed to examine the relationship between depressive symptoms and cognitive performance. Statistical parametric mapping explored age-dependent associations between depressive symptoms and grey matter volume. Cognitive performance was associated with a significant age by depression by cognitive domain interaction, indicating that older individuals with more depressive symptoms had a lower cognitive performance, particularly in the fluency domain. Structural MRI revealed preferential depression-related reduction in grey matter volume in the left and right hippocampi in older adults. By contrast, in younger adults, depressive symptoms were more strongly associated with grey matter volume reduction in the left superior frontal gyrus and left middle frontal gyrus. Collectively, these findings indicate that the associations of depression with cognitive performance and brain structure are age-dependent, suggesting that the pathophysiological mechanisms underlying depression may differ between young and older adults. Recognizing these differences will support the development of better diagnostic tools and therapeutic interventions for depression across the lifespan.

Reconsidering remission in recurrent late-life depression: clinical presentation and phenotypic predictors of relapse following successful antidepressant treatment

BACKGROUND

Late-life depression (LLD) is characterized by repeated recurrent depressive episodes even with maintenance treatment. It is unclear what clinical and cognitive phenotypic characteristics present during remission predict future recurrence.

METHODS

Participants (135 with remitted LLD and 69 comparison subjects across three institutions) completed baseline phenotyping, including psychiatric, medical, and social history, psychiatric symptom and personality trait assessment, and neuropsychological testing. Participants were clinically assessed every two months for two years while receiving standard antidepressant treatment. Analyses examined group differences in phenotypic measure using general linear models. Concurrent associations between phenotypic measures and diagnostic groups were examined using LASSO logistic regression.

RESULTS

Sixty (44%) LLD participants experienced a relapse over the two-year period. Numerous phenotypic measures across all domains differed between remitted LLD and comparison participants. Only residual depressive symptom severity, rumination, medical comorbidity, and executive dysfunction significantly predicted LLD classification. Fewer measures differed between relapsing and sustained remission LLD subgroups, with the relapsing group exhibiting greater antidepressant treatment intensity, greater fatigue, rumination, and disability, higher systolic blood pressure, greater life stress and lower instrumental social support. Relapsing group classification was informed by antidepressant treatment intensity, lower instrumental social support, and greater life stress.

CONCLUSIONS

A wide range of phenotypic factors differed between remitted LLD and comparison groups. Fewer measures differed between relapsing and sustained remission LLD subgroups, with less social support and greater stress informing vulnerability to subsequent relapse. This research suggests potential targets for relapse prevention and emphasizes the need for clinically translatable relapse biomarkers to inform care.

Depressive symptoms, cognitive functions and daily activities: An extended network analysis in monozygotic and dizygotic twins

BACKGROUND

The network theory posits that depression emerges as the result of individual symptoms triggering each other. Risk factors for depression can impact these between-symptoms interactions through extended networks. The study aimed to model the extended network of depressive symptoms and known depression risk factors - objective cognitive function, intellectual, physical, and social daily activities, and then, compare the observed networks between monozygotic (MZ) and dizygotic (DZ) co-twins.

METHODS

Twin pairs, 722 MZ and 2200 DZ, aged 40-79, were selected from the Dansh Twin Registry for having complete measures of depressive symptoms (e.g., sadness), cognitive functions (e.g., verbal memory), physical (e.g., brisk walk), intellectual (e.g., reading newspapers) and social activities (e.g., phone calls). Gaussian graphical models were used to estimate and compare the networks first between co-twins and then, between MZ to DZ twin pairs separately.

RESULTS

Specific intellectual, physical and social activities were central in the extended networks of depressive symptoms and, with the exception of processing speed, more central than cognition. The extended networks' structure was more homogeneous between MZ co-twins relative to DZ co-twins. Cognitive nodes were more central in MZ than DZ co-twins.

LIMITATIONS

Cross-sectional design, participants were middle-aged or older, mostly affective (non-somatic) depressive symptoms.

CONCLUSIONS

In depression networks, core connecting elements were intellectual, physical and social activities. The interaction between cognition and daily activities seems critical for triggering depressive symptoms. Thus, clinical interventions aimed at preventing depression and associated cognitive deficits should focus on maintenance and/or engagement in stimulating daily activities.

Comparison of the Antianhedonic Effects of Repeated-dose Intravenous Ketamine in Older and Younger Adults with Major Depressive Episode

OBJECTIVES

Growing evidence suggests that repeated-dose intravenous ketamine in patients with depression had rapid antianhedonic effects. However, a comparison of the antianhedonic effects of repeated-dose intravenous ketamine between younger adults and older depressed patients has not been examined.

METHODS

To the best of my knowledge, this study with a total of 135 patients with major depressive episodes (MDE) is the first to compare the antianhedonic effects between younger adult (n = 116) and older (n = 19) depressed patients receiving six ketamine infusions (0.5 mg/kg over 40 min). Montgomery- Åsberg Depression Rating Scale (MADRS) was applied in this study to evaluate the clinical symptoms, and MADRS anhedonia item scoring was used to evaluate anhedonia symptoms.

RESULTS

Patients received six open-label intravenous infusions of ketamine for 12 days. MADRS anhedonia subscale scores decreased in both younger (3.3, 95% CI = 2.5-4.1, p < 0.05) and older (2.8, 95% CI = 1.1-4.6, p < 0.05) MDE patients at 4h after the first infusion compared to baseline scores and the reduction was maintained over the subsequent infusion period in both groups (all Ps < 0.05). Younger MDE patients had lower MADRS anhedonia subscale scores on day 26 compared with older patients (P = 0.02). Compared with younger adult MDE patients, older patients had a lower antianhedonic response (51.7% [95% CI = 42.5%-61.0%] versus 31.6% [95% CI = 8.6%-54.6%)] and remission (24.1% [95% CI = 16.2%-32.0%] versus 0%).

CONCLUSION

This study indicates that repeated-dose intravenous ketamine administration induces rapid and robust antianhedonic effects in older MDE patients. However, older MDE patients displayed less response to ketamine than younger adult MDE patients.

Acoustic speech features are associated with late-life depression and apathy symptoms: Preliminary findings

BACKGROUND

Late-life depression (LLD) is a heterogenous disorder related to cognitive decline and neurodegenerative processes, raising a need for the development of novel biomarkers. We sought to provide preliminary evidence for acoustic speech signatures sensitive to LLD and their relationship to depressive dimensions.

METHODS

Forty patients (24 female, aged 65-82 years) were assessed with the Geriatric Depression Scale (GDS). Vocal features were extracted from speech samples (reading a pre-written text) and tested as classifiers of LLD using random forest and XGBoost models. Post hoc analyses examined the relationship between these acoustic features and specific depressive dimensions.

RESULTS

The classification models demonstrated moderate discriminative ability for LLD with receiver operating characteristic = 0.78 for random forest and 0.84 for XGBoost in an out-of-sample testing set. The top classifying features were most strongly associated with the apathy dimension (R 2 = 0.43).

DISCUSSION

Acoustic vocal features that may support the diagnosis of LLD are preferentially associated with apathy.

Highlights

The depressive dimensions in late-life depression (LLD) have different cognitive correlates, with apathy characterized by more pronounced cognitive impairment.Acoustic speech features can predict LLD. Using acoustic features, we were able to train a random forest model to predict LLD in a held-out sample.Acoustic speech features that predict LLD are preferentially associated with apathy. These results indicate a predominance of apathy in the vocal signatures of LLD, and suggest that the clinical heterogeneity of LLD should be considered in development of acoustic markers.

The association between 'weekend warrior', regular exercise, and cognitive function in elderly individuals with and without depressive symptoms: A cross-sectional analysis from NHANES 2011-2014

BACKGROUND

While previous studies have suggested that both 'Weekend Warrior' (WW) and Regular Exercise (RE) patterns confer health benefits, the relationship between different types of physical activity (PA) and cognitive function (CF) in elderly individuals with and without depressive symptoms remains unclear.

METHODS

Our study leveraged the NHANES 2011-2014 dataset, focusing on older adults. We explore the relationship between PA and CF, stratifying by depressive status. Our statistical approach included multivariable regression analysis to identify relationships between PA levels and cognitive outcomes, along with advanced techniques such as smoothed curve fitting and threshold effect analysis to examine potential nonlinear associations and identify optimal PA pattern for cognitive health.

RESULTS

Analysis revealed a positive correlation between PA time and CF across all participants (β-depressive symptoms = 0.03, 95 % CI: 0.01-0.05; β-non-depressive symptoms = 0.01, 95%CI: 0.00-0.02). When comparing against the inactive, non-depressed participants partaking in WW showed improved cognitive scores (β-WW = 0.22, 95 % CI: 0.05-0.39), similar to those engaging in RE (β-RE = 0.15, 95 % CI: 0.09-0.21). However, among the depressed participants, significant cognitive improvements were observed in the RE (β-RE = 0.15, 95 % CI: 0.04-0.25), with the WW showing less definitive results (β-WW = 0.22, 95 % CI: -0.02-0.47).

LIMITATION

The cross-sectional nature limits causal inferences.

CONCLUSION

Our findings affirm the potential role of PA in enhancing CF among older subjects without depressive symptoms. However, only RE was associated with improved CF in those with depressive symptoms. These results are critical for crafting personalized PA guidelines to enhance cognitive health in the aging population.

Clinical Phenotype of Behavioral-Variant Frontotemporal Dementia Reversed by ECT: A Case Report

INTRODUCTION

Diagnosis of frontotemporal dementia (FTD) remains difficult even in the presence of core clinical and imaging features. Furthermore, disease-modifying treatments are lacking.

CASE PRESENTATION

Here, we report a case of a patient with clinical and imaging features of FTD. Electroconvulsive therapy (ECT) was used to target affective and catatonic symptoms. After ECT, the patient showed improvements not only in affective symptoms but also in cognitive domains, leading to a marked improvement in the patient's level of functioning.

CONCLUSION

Against the background of diagnostic uncertainty and lack of disease-modifying treatments for FTD, we emphasize the importance of focusing on treatable symptoms. Thus, we recommend consideration of ECT as a viable option for multiple symptom domains. In this case of bvFTD, ECT was well-tolerated with relatively low side-effects.

Bereavement due to child loss, divorce, and depressive mood in older age across European welfare regimes

While bereavement, particularly the loss of a child, is a well-known risk factor for mental health in the short term, its long-term consequences on depressive mood in old age and across different welfare regimes have been investigated less. This study focused on the combined role of child loss and divorce on depressive symptoms, measured using the EURO-D scale in Central, Nordic, Southern, and Eastern European countries. We used data from the European SHARE project, covering 22,959 participants aged 50+ over a 16-year period. Using OLS regressions, we found that, compared to no child loss and no divorce, the association between depressive symptoms and child loss was significant ( β  = 0.22, 95% C.I. = [0.13, 0.30]), among both women and men. The absolute increase was even stronger when the mutual effect of child loss and divorce was considered ( β  = 0.34, 95% C.I. = [0.18, 0.48]). Employing Generalized Estimating Equations, we found that depressive symptoms related to divorce did not increase over time, regardless of past bereavement. Compared with people in the Nordic countries, those living in Southern Europe experienced more depressive symptoms related to child loss and no divorce, but fewer depressive symptoms related to the combined effect of child loss and divorce. In sum, our findings indicate that bereavement due to child loss may lead to more depressive symptoms among both women and men in old age, especially in combination with divorce. In the latter case, we posit that participants living in Southern European countries may be protected by higher levels of social support through family ties or informal social networks.

Exploring the Complex Relationship Between Antidepressants, Depression and Neurocognitive Disorders

The coexistence of dementia and depression in older populations presents a complex clinical challenge, with each condition often exacerbating the other. Cognitive decline can intensify mood disturbances, and untreated or recurring depression accelerates neurodegenerative processes. As depression is a recognized risk factor for dementia, it is crucial to address both conditions concurrently to prevent further deterioration. Antidepressants are frequently used to manage depression in dementia patients, with some studies suggesting they offer neuroprotective benefits. These benefits include promoting neurogenesis, enhancing synaptic plasticity, and reducing neuroinflammation, potentially slowing cognitive decline. Additionally, antidepressants have shown promise in addressing Alzheimer's-related pathologies by reducing amyloid-beta accumulation and tau hyperphosphorylation. However, treatment-resistant depression remains a significant challenge, particularly in older adults with cognitive impairment. Many do not respond well to standard antidepressant therapies due to advanced neurodegenerative changes. Conflicting findings from studies add to the uncertainty, with some research suggesting that antidepressants may increase dementia risk, especially when used in patients with undiagnosed early-stage dementia. This article aims to explore the intricate relationship between depression and dementia, examining the benefits and risks of antidepressant use. We highlight the urgent need for personalized, comprehensive treatment strategies that balance mental health improvement with cognitive protection.

Efficacy and safety of Neurocognitive Adaptive Training for Depression combined with SSRIs for treating cognitive impairment among patients with late-life depression: a 12-week, randomized controlled study

BACKGROUND

This randomized, open-label study examined the therapeutic effects of Neurocognitive Adaptive Training for Depression (NCAT-D) combined with selective serotonin reuptake inhibitors (SSRIs) on cognitive impairment among patients with late-life depression (LLD).

METHOD

Study data were collected from May 5, 2021, to April 21, 2023. Outpatients who met the diagnostic criteria for major depressive disorder according to the fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) (i.e., a total score on the 17-item Hamilton Depression Rating Scale (HAMD-17) ≥ 18 and a total score on the Montreal Cognitive Assessment scale (MOCA) < 26) were recruited at Beijing Anding Hospital. These participants were randomly assigned to receive up to 12 weeks of NCAT-D and SSRIs treatment (n = 57) or SSRIs with a control treatment (n = 61). Primary outcomes included changes in Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) scores from baseline to week 12 between the two groups. Assessments were conducted at baseline, after 2 weeks, 4 weeks, 8 weeks, and at 12 weeks. Mixed model repeated measures (MMRM) analysis was performed on modified intention-to-treat (mITT) and completer populations.

RESULTS

The full analysis set (FAS) included 118 patients (NCAT-D and SSRIs group, n = 57; SSRIs and Control group, n = 61). During the 12-week study period, MMRM analysis revealed a significantly greater reduction in cognitive function (as indicated by ADAS-cog total scores) from baseline to post-treatment in the NCAT-D and SSRIs group compared to the SSRIs and Control groups [(F (1,115) = 13.65, least-squares mean difference [95% CI]: -2.77 [- 3.73, - 1.81], p < 0.001)]. The intervention group showed a significantly greater reduction in HAMD-17 scores compared to the control group [MMRM, estimated mean difference (SE) between groups: -3.59 [- 5.02, - 2.15], p < 0.001]. There was no significant difference in the incidence of adverse events between the two groups.

CONCLUSIONS

NCAT-D combined with SSRIs was efficacious and well tolerated in LLD patients with cognitive impairment.

TRIAL REGISTRATION

Registered on October 18, 2022, at ClinicalTrials.gov Identifier: (#NCT05588102).

Mediating effect of social support and resilience between loneliness and depression in older adults: A systematic review and meta-analytic structural equation modeling

BACKGROUND

Loneliness is a powerful stressor for depression in older adults, and resilience and social support may mediate this relationship, while the evidence is limited. Hence, our study aims to explore the mediating role of social support and resilience between loneliness and depression and to test possible moderators.

METHODS

We searched 12 databases without language and publish time restrictions and obtained the correlation coefficients. This review constructed two-stage meta-analytical structural equality modeling (MASEA) to test the mediating effect of social support and resilience. Additionally, use one-stage MASEA to test the moderator effect of women proportion, published year, and country of study.

RESULTS

This study included 53 studies and 40, 929 older adults. Loneliness directly affected depression (β = 0.28, 95 % CI: 0.20, 0.36). Social support (β = 0.06, 95 % CI: 0.02, 0.09) and resilience (β = 0.15, 95 % CI: 0.12, 0.18) mediated the relationship. The proportion of women in the sample was moderator (χ2(5) = 11.10, p = 0.05). When the proportion exceeded 60 %, the path coefficient of loneliness and social support (β = -0.45, SE = 0.055) was larger than that of the subgroup below 60 % (β = -0.32, SE = 0.041).

LIMITATIONS

It was indefinite whether the evidence would be supported in longitudinal designs. Influenced by the original research data, it is impossible to calculate the model parameters of gender discrepancy.

CONCLUSIONS

Health aging policy-makers adopting social support and resilience intervention will help strengthen the coping skills of older adults confronting loneliness and reduce the risk of depression.

Mental and physical health characteristics of older and younger adults receiving medication for opioid use disorder

Background

Methadone is an effective and widely used medication for opioid use disorder (MOUD). Within in the United States (US), older adults represent an increasing proportion of those receiving MOUD, yet little is known about characteristics of older individuals in these programs.

Objectives

To evaluate mental and physical health characteristics of younger and older adults receiving MOUD and test whether age moderates the relation between physical and mental health variables.

Methods

Data for this secondary analysis are drawn from a cross-sectional survey of a convenience sample of individuals seeking methadone dosing as part of MOUD at four opioid treatment programs in two regions of the US. Descriptive statistics and correlational and moderation analyses examined outcomes of pain severity, pain interference, self-rated health, physical activity, depression, and anxiety across younger (18-49) and older (50+ years) participants.

Results

Analyses included 469 participants (mean [range] age, 41.01 [20-70] years). Older participants reported higher pain severity and interference, less physical activity, and worse self-rated health than those in the younger age group (ps < 0.05). Associations between mental and physical health variables were generally weak-to-moderate in the older age group (r = 0.26 to r = 0.44, p < 0.01), and weak in the younger age group, although age did not moderate associations.

Conclusion

Clinically significant mental and physical health variables are associated among individuals receiving methadone for MOUD, with older adults facing unique challenges.

Clinical implications

Opioid use treatment should include not only pain management but also assessment and treatment of depression and anxiety and optimization of other health behaviors (e.g., physical activity) across age groups. Pain management and health promotion are particularly relevant targets for aging individuals receiving MOUD.

Prediction of electroconvulsive therapy response and remission in late-life depression: a review

Electroconvulsive therapy is an effective and well-tolerated antidepressant treatment for the elderly population. The place of electroconvulsive therapy in the treatment sequence for depression in the elderly is currently not well established. This review aims to identify the factors that contribute to a positive response and remission in elderly patients with depression undergoing electroconvulsive therapy treatment. We searched five bibliographic databases (Medline ALL Ovid, Embase.com, APA PsycInfo Ovid, Cochrane Library Wiley and Web of Science Core Collection) for articles published between 1995 and June 2023. Of the 2149 articles screened, 19 were included in the review. No significant associations were found between remission and/or response and salivary cortisol, baseline hippocampal and white matter hyperintensities, total amyloid load or global cortical atrophy. The reviewed articles did not show a significant difference in remission between unilateral and bilateral electroconvulsive therapy treatment. Other interesting findings are that moderately elevated levels of CRP and S100B levels, lower retardation scores, poorer performance on the word reading task at baseline and longer post-ictal reorientation time may be associated with higher remission and/or response rates. Medial temporal atrophy can be associated with lower Montgomery-Åsberg Depression Rating Scale (MADRS) decrease after electroconvulsive therapy. Finally, elderly patients had higher rates of electroconvulsive therapy response; retardation and psychotic features may mediate this association. Incorporation of this data into clinical practice may facilitate a personalised approach to electroconvulsive therapy. However, research on this topic is scarce and there are few studies that focus specifically on older people.

Depressive symptoms and cognitive decline in older adults

OBJECTIVES

Few studies have examined the impact of late-life depression trajectories on specific domains of cognitive function. This study aims to delineate how different depressive symptom trajectories specifically affect cognitive function in older adults.

DESIGN

Prospective longitudinal cohort study.

SETTING

Australia and the United States of America.

PARTICIPANTS

In total, 11,035 community-dwelling older adults with a mean age of 75 years.

MEASUREMENTS

Depressive trajectories were modelled from depressive symptoms according to annual Centre for Epidemiological Studies Depression Scale 10 (CES-D-10) surveys. Four trajectories of depressive symptoms were identified: low ("nondepressed"), consistently mild ("subthreshold depression"), consistently moderate ("persistent depression"), and initially low but increasing ("emerging depression"). Global cognition (Modified Mini-Mental State Examination [3MS]), verbal fluency (Controlled Oral Word Association Test [COWAT]), processing speed (Symbol Digit Modalities Test [SDMT]), episodic memory (Hopkins Verbal Learning Test - Revised [HVLT-R]), and a composite z-score were assessed over a subsequent median 2 years.

RESULTS

Subthreshold depression predicted impaired performance on the SDMT (Cohen's d -0.04) and composite score (-0.03); emerging depression predicted impaired performance on the SDMT (-0.13), HVLT-R (-0.09), 3 MS (-0.08) and composite score (-0.09); and persistent depression predicted impaired performance on the SDMT (-0.08), 3 MS (-0.11), and composite score (-0.09).

CONCLUSIONS

Depressive symptoms are associated with later impaired processing speed. These effects are small. Diverse depression trajectories have different impacts on cognitive function.

Modifiable risk factors and excess mortality in depression: Data from the UK Biobank

OBJECTIVE

To study the role of modifiable risk factors in explaining the excess mortality associated with depression using data from the UK Biobank, a middle-aged and elderly cohort recruited in 2006-2010.

METHODS

We estimated the prevalence and relative mortality associated with modifiable risk factors and groups of risk factors (socioeconomic factors, diet and exercise, smoking and substance-related disorders, and cardiometabolic diseases) in a subsample of probable cases of lifetime/current depression (n = 51,302) versus non-cases. We also estimated the relative mortality associated with depression and the percentages of excess mortality associated with depression explained by modifiable risk factors in the total sample (499,762).

RESULTS

In our depression subsample, all modifiable risk factors were associated with increased prevalence and mortality. In our total sample, depression was associated with an age and sex-adjusted mortality hazard ratio of 1.63 (95% CI = [1.58-1.68]). Modifiable risk factors explained 70.5% [66.9%-75.0%] of the excess mortality associated with depression.

CONCLUSIONS

In the UK Biobank cohort, depression was associated with a higher prevalence of modifiable risk factors. These risk factors were associated with increased mortality in the depression subsample and explained most of the excess mortality risk associated with depression in the total sample.

Grey matter volume predicts improvement in geriatric depression in response to Tai Chi compared to Health Education

OBJECTIVES

Geriatric depression (GD) is associated with cognitive impairment and brain atrophy. Tai-Chi-Chih (TCC) is a promising adjunct treatment to antidepressants. We previously found beneficial effects of TCC on resting state connectivity in GD. We now tested the effect of TCC on gray matter volume (GMV) change and the association between baseline GMV and clinical outcome.

PARTICIPANTS

Forty-nine participants with GD (>=60 y) underwent antidepressant treatment (38 women).

INTERVENTION

Participants completed 3 months of TCC (N = 26) or health and wellness education control (HEW; N = 23).

MEASUREMENTS

Depression and anxiety symptoms and MRI scans were acquired at baseline and 3-month follow-up. General linear models (GLMs) tested group-by-time interactions on clinical scores. Freesurfer 6.0 was used to process T1-weighted images and to perform voxel-wise whole-brain GLMs of group on symmetrized percent GMV change, and on the baseline GMV and symptom change association, controlling for baseline symptom severity. Age and sex served as covariates in all models.

RESULTS

There were no group differences in baseline demographics or clinical scores, symptom change from baseline to follow-up, or treatment-related GMV change. However, whole-brain analysis revealed that lower baseline GMV in several clusters in the TCC, but not the HEW group, was associated with larger improvements in anxiety. This was similar for right precuneus GMV and depressive symptoms.

CONCLUSIONS

While we observed no effect on GMV due to the interventions, baseline regional GMV predicted symptom improvements with TCC but not HEW. Longer trials are needed to investigate the long-term effects of TCC on clinical symptoms and neuroplasticity.

Cognitive Profiles in Treatment-Resistant Late-Life Depression and Their Impact on Treatment Outcomes

BACKGROUND

Late-life depression (LLD) is associated with cognitive impairment, but substantial heterogeneity exists among patients. Data on the extent of cognitive impairments are inconclusive, particularly in patients with treatment-resistant depression (TRD). We investigated the cognitive profiles of patients with treatment-resistant versus nonresistant LLD and aimed to identify distinct cognitive subgroups. We also examined whether cognitive subgroups responded differentially to treatment with bilateral repetitive transcranial magnetic stimulation (rTMS).

METHODS

A total of 165 patients with LLD were divided into treatment-resistant and nonresistant groups and compared with healthy control participants on measures of executive function, information processing speed, verbal learning, and memory. Cluster analysis identified subgroups based on cognitive scores. Demographic and clinical variables, as well as outcomes with bilateral rTMS, were compared between cognitive subgroups.

RESULTS

Patients with LLD, particularly TRD, exhibited significantly worse cognitive performance than healthy controls. A 3-cluster solution was found, including cognitively intact (n = 89), cognitively diminished (n = 29), and impaired memory (n = 47) subgroups. Both the cognitively diminished and impaired memory subgroups had more anxiety symptoms and a higher proportion of patients with TRD than the cognitively intact group, although the latter difference did not survive multiple comparison correction. No significant differences were observed in outcomes to rTMS treatment.

CONCLUSIONS

Patients with LLD exhibited impairments across cognitive domains, which were more pronounced in TRD. Three cognitive subgroups responded similarly to rTMS treatment, indicating its effectiveness across cognitive profiles, especially when medications are not tolerated. Future research should examine the relationships among cognitive subgroups, cognitive decline, and neurodegeneration.

Efficacy of problem-solving therapy in treating late-life depression with potential cognitive impairment: a systematic review and meta-analysis

INTRODUCTION

Late-life depression (LLD) is a global public health issue, often accompanied by cognitive impairments that can exacerbate the severity of depression and impair social functioning. Despite being a well-established treatment for LLD, the suitability of problem-solving therapy (PST) for individuals with LLD and varying degrees of cognitive impairments warrants further investigation. This paper presents the protocol for a systematic review and meta-analysis of randomised controlled trials (RCTs) aimed at evaluating the effectiveness and acceptability of PST for this specific demographic.

METHODS/ANALYSIS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we will conduct a systematic review to synthesise existing research on PST for individuals in this demographic. We will comprehensively search multiple databases and sources, including PubMed, EMBASE, the Cochrane Database and APA PsycNET from inception to October 2023, without language, publication year or type restrictions. Relevant studies will be manually screened from the references. Only RCTs involving PST for LLD will be included. The primary efficacy outcome will be the standardised mean difference in total scores on continuous depression severity scales across different comparison arms. Data extraction will be conducted independently by two reviewers (CH and J-JW), and methodological rigour will be assessed using the Cochrane Risk of Bias assessment tool. Subgroup and sensitivity analyses will be performed to investigate the impact of concomitant cognitive impairments and to evaluate the robustness of the findings.

ETHICS AND DISSEMINATION

The meta-analysis project is expected to be ethically unproblematic and does not require approval from a research ethics committee. The results of this study will be shared through articles in scholarly peer-reviewed journals and presentations in various formats, both print and digital.

PROSPERO REGISTRATION NUMBER

CRD42023473782.

Brain inflammaging in the pathogenesis of late-life depression

Late-life depression (LLD) is a prevalent mental disorder among older adults. Previous studies revealed that many pathologic factors are associated with the onset and development of LLD. However, the precise mechanisms that cause LLD remain elusive. Aging induces chronic inflammatory changes mediated by alterations of immune responses. The chronic systemic inflammation termed "inflammaging" is linked to the etiology of aging-related disorders. Aged microglia induce senescence-associated secretory phenotype (SASP) and transition to M1-phenotype, cause neuroinflammation, and diminish neuroprotective effects. In addition, there is an age-dependent loss of blood-brain barrier (BBB) integrity. As the BBB breakdown can lead to invasion of immune cells into brain parenchyma, peripheral immunosenescence may cause microglial activation and neuroinflammation. Therefore, it is suggested that these mechanisms related to brain inflammaging may be involved in the pathogenesis of LLD. In this review, we described the role of brain inflammaging in LLD. Pharmacologic approaches to prevent brain inflammaging appears to be a promising strategy for treating LLD.

Association between chronic disease status and transitions in depressive symptoms among middle-aged and older Chinese population: Insights from a Markov model-based cohort study

BACKGROUND

The relationship between chronic disease status (CDS) and transitions in depressive symptoms (DS) remains unclear. This study explores the association between CDS and DS transitions.

METHODS

This cohort study analyzed data from 8175 participants aged 45+, sourced from China Family Panel Studies (2016, 2018, 2020). DS were assessed using a brief version of Center for Epidemiologic Studies Depression Scale (CES-D). CDS was categorized into healthy, single disease, and multimorbidity. Markov models were used to estimate state transition intensities, mean sojourn times and hazard ratios (HRs).

RESULTS

DS transitions occurred between adjacent and non-adjacent states, but transition intensity between adjacent states was higher than among non-adjacent states. Self-transition intensities of severe-DS, mild-DS, and non-DS progressively increased, with average durations of 1.365, 1.482, and 7.854 years, respectively. Both single disease and multimorbidity were significantly associated with an increased risk of transitioning from non-DS to mild-DS, with multimorbidity showing a stronger association. In contrast, HRs for single diseases transitioning from mild-DS to severe-DS were significantly lower than 1. Furthermore, their HRs were almost <1 in recovery transitions but not statistically significant.

LIMITATIONS

Specific chronic diseases and their combinations were not analyzed.

CONCLUSIONS

The progression of DS exhibits various pathways. CDS is associated with DS transitions, but the roles of single disease and multimorbidity may differ across different DS progression stages. Both conditions were significantly linked to the risk of new-onset DS, with multimorbidity posing a greater association. However, this relationship is not observed in other progression stages. These findings could provide insights for early prevention and intervention for DS.

Fast-acting antidepressant-like effects of ketamine in aged male rats

BACKGROUND

The aging process causes anatomical and physiological changes that predispose to the development of late-life depression while reduces the efficacy of classical antidepressants. Novel fast-acting antidepressants such as ketamine might be good candidates to be explored in the context of aging, especially given the lack of previous research on its efficacy for this age period. Thus, the aim of the present study was to characterize ketamine's effects in older rats.

METHODS

The fast-acting (30 min) and repeated (7 days) antidepressant-like effects of ketamine (5 mg/kg, ip) were evaluated in 14-month-old single-housed rats through the forced-swim and novelty-suppressed feeding tests. In parallel, the modulation of neurotrophic-related proteins (i.e., mBDNF, mTOR, GSK3) was assessed in brain regions affected by the aging process, prefrontal cortex and hippocampus, as well as possible changes in hippocampal cell proliferation.

RESULTS

Acute ketamine induced a fast-acting antidepressant-like response in male aged rats, as observed by a reduced immobility in the forced-swim test, in parallel with a region-specific increase in mBDNF protein content in prefrontal cortex. However, repeated ketamine failed to induce antidepressant-like efficacy, but decreased mBDNF protein content in prefrontal cortex. The rate of hippocampal cell proliferation and/or other markers evaluated was not modulated by either paradigm of ketamine.

CONCLUSIONS

These results complement prior data supporting a fast-acting antidepressant-like effect of ketamine in rats, to further extend its efficacy to older ages. Future studies are needed to further clarify the lack of response after the repeated treatment as well as its potential adverse effects in aging.

Regional gray matter changes in steatotic liver disease provide a neurobiological link to depression: A cross-sectional UK Biobank cohort study

BACKGROUND

Steatotic liver disease (SLD) is characterized by excessive accumulation of lipids in the liver. It is associated with elevated risk of hepatic and cardiometabolic diseases, as well as mental disorders such as depression. Previous studies revealed global gray matter reduction in SLD. To investigate a possible shared neurobiology with depression, we examined liver fat-related regional gray matter alterations in SLD and its most significant clinical subgroup metabolic dysfunction-associated steatotic liver disease (MASLD).

METHODS

We analyzed regional cortical thickness and area obtained from brain MRI in 29,051 participants in UK Biobank. Liver fat amount was computed as proton density fat fraction (PDFF) from liver MRI scans. We examined the relationship between brain structure and PDFF, adjusting for sociodemographic, physical, lifestyle, and environmental factors, as well as alcohol intake and a spectrum of cardiometabolic covariates. Finally, we compared patterns of brain alterations in SLD/MASLD and major depressive disorder (MDD) using previously published results.

RESULTS

PDFF-related gray matter alterations were region-specific, involving both increases and decreases in cortical thickness, and increased cortical area. In several regions, PDFF effects on gray matter could also be attributed to cardiometabolic covariates. However, PDFF was consistently associated with lower cortical thickness in middle and superior temporal regions and higher cortical thickness in pericalcarine and right frontal pole regions. PDFF-related alterations for the SLD and the MASLD group correlated with those observed in MDD (Pearson r = 0.45-0.54, p < 0.01).

CONCLUSION

These findings suggest the presence of shared biological mechanisms linking MDD to SLD and MASLD. They might explain the well-known elevated risk of depression in these groups and support early lifestyle interventions and treatment of metabolic risk factors for the successful management of the interconnected diseases depression and SLD/MASLD.

Effects of open-label transdermal nicotine antidepressant augmentation on affective symptoms and executive function in late-life depression

BACKGROUND

Late-life depression (LLD) is characterized by a poor response to antidepressant medications and diminished cognitive performance, particularly in executive functioning. There is currently no accepted pharmacotherapy for LLD that effectively treats both mood and cognitive symptoms. This study investigated whether transdermal nicotine augmentation of standard antidepressant medications benefitted mood and cognitive symptoms in LLD.

METHODS

Nonsmoking participants aged 60 years or older with unremitted LLD on stable SSRI or SNRI medications (N = 29) received transdermal nicotine patches up to a 21 mg daily dose over 12 weeks. Clinical measures assessed depression severity, secondary affective symptoms, and cognitive performance. Nicotine metabolite concentrations were obtained from blood samples.

RESULTS

Depression severity significantly decreased over the trial, with a 76 % response rate and 59 % remission rate. Change in depression severity was positively associated with nicotine exposure. Participants also exhibited improvement in self-reported affective symptoms (apathy, insomnia, rumination, and generalized anxiety symptoms), negativity bias, and disability. Executive function test performance significantly improved, specifically in measures of cognitive control, as did subjective cognitive performance. Adverse events were generally mild, with 75 % of the sample tolerating the maximum dose.

CONCLUSION

The current study extends our previous pilot open-label trial in LLD, supporting feasibility and tolerability of transdermal nicotine patches as antidepressant augmentation. Although preliminary, this open-label study supports the potential benefit of transdermal nicotine patches for both mood and cognitive symptoms of LLD. Further research, including definitive randomized, blinded trials, is warranted to confirm these findings and explore long-term risk and benefit.

TRIAL REGISTRATION

The study was registered with clinicaltrials.gov (NCT04433767).

Cognitive improvement in late-life depression treated with vortioxetine and duloxetine in an eight-week randomized controlled trial: The role of age at first onset and change in depressive symptoms

BACKGROUND

Age at first onset of depression as a clinical factor affecting cognitive improvement in late life depression was investigated.

METHODS

This is a secondary analysis of an eight-week randomized controlled trial involving 452 elderly patients treated by vortioxetine, duloxetine or placebo (1:1:1). Patients were subcategorized into early-onset (LLD-EO) and late-onset (LLD-LO) groups divided by onset age of 50. Cognitive performance was assessed by composite score of Digit Symbol Substitution Test (DSST) and the Rey Auditory Verbal Learning Test (RAVLT) tasks, while depressive symptoms were assessed by Montgomery-Åsberg Depression Rating Scale (MADRS).

RESULTS

Vortioxetine and duloxetine exhibited advantages versus placebo in improving cognitive performance in the LLD-LO group, yet not in the LLD-EO group after eight weeks. Patients in the LLD-EO group showed overall advantage to placebo in depressive symptoms before endpoint (week 8) of treatment, while patients in the LLO-LO group showed no advantage until endpoint. Path analysis suggested a direct effect of vortioxetine (B = 0.656, p = .036) and duloxetine (B = 0.726, p = .028) on improving cognition in the LLD-LO group, yet in all-patients treated set both medications improved cognition indirectly through changes of depressive symptoms.

LIMITATION

Reliability of clinical history could raise caution as it was collected by subjective recall of patients.

CONCLUSION

Age at first onset might affect cognitive improvement as well as change in depressive symptoms and its mediation towards cognitive improvement in late life depression treated with vortioxetine and duloxetine.

Microstructural brain assessment in late-life depression and apathy using diffusion MRI multi-compartments models and tractometry

Late-life depression (LLD) is both common and disabling and doubles the risk of dementia onset. Apathy might constitute an additional risk of cognitive decline but clear understanding of its pathophysiology is lacking. While white matter (WM) alterations have been assessed using diffusion tensor imaging (DTI), this model cannot accurately represent WM microstructure. We hypothesized that a more complex multi-compartment model would provide new biomarkers of LLD and apathy. Fifty-six individuals (LLD n = 35, 26 females, 75.2 ± 6.4 years, apathy evaluation scale scores (41.8 ± 8.7) and Healthy controls, n = 21, 16 females, 74.7 ± 5.2 years) were included. In this article, a tract-based approach was conducted to investigate novel diffusion model biomarkers of LLD and apathy by interpolating microstructural metrics directly along the fiber bundle. We performed multivariate statistical analysis, combined with principal component analysis for dimensional data reduction. We then tested the utility of our framework by demonstrating classically reported from the literature modifications in LDD while reporting new results of biological-basis of apathy in LLD. Finally, we aimed to investigate the relationship between apathy and microstructure in different fiber bundles. Our study suggests that new fiber bundles, such as the striato-premotor tracts, may be involved in LLD and apathy, which bring new light of apathy mechanisms in major depression. We also identified statistical changes in diffusion MRI metrics in 5 different tracts, previously reported in major cognitive disorders dementia, suggesting that these alterations among these tracts are both involved in motivation and cognition and might explain how apathy is a prodromal phase of degenerative disorders.

Association of depressive symptoms with cardiovascular events and plasma BNP: A prospective cohort study of the elderly Chinese population

OBJECTIVE

To estimate the prevalence of depressive symptoms and to evaluate the associations of mild and significant depressive symptoms with cardiovascular events and plasma BNP levels (which are surrogate endpoints for cardiovascular events) among older adults in a population-based study.

METHODS

A population-based prospective study of 1,432 elderly people (aged 70-84 years and without cardiovascular disease) was conducted, and the median duration of follow-up for participants with outcomes was 18 weeks. Depressive symptoms were assessed with the 15-item Geriatric Depression Scale (GDS-15). The hazard ratios (HRs) for the time to events and time to death were calculated using the Cox regression analysis. Multiple linear regression models and Spearman rank correlations were used to examine the association of depressive symptoms with Log BNP values.

RESULTS

The prevalence of mild (GDS-15 scores ≥ 6) and significant (GDS-15 scores ≥ 10) depressive symptoms were 7.3% and 2.0% at baseline, respectively. Older adults with significant depressive symptoms exhibited increased risks of time to death (HR: 12.56; 95% CI: 3.58-43.99) and composite cardiovascular endpoints (HR: 3.46; 95% CI: 1.19-3.75). Significant depressive symptoms were associated with Log BNP levels (β=0.56, P = 0.02). Depressive symptom scores were also associated with Log BNP levels (rs=0.21, P = 0.04) in the older adults with depressive symptoms.

CONCLUSIONS

Significant depressive symptoms were associated with a higher risk of cardiovascular events and higher BNP levels in the elderly.

Subjective and objective cognitive functioning in untreated late-life depression: An exploration centered on comorbid generalized anxiety disorder

BACKGROUND

Late-Life Depression (LLD) is a prevalent mental health disorder that is often accompanied by cognitive impairments. The objective of this study is to investigate the influence of coexisting Generalized Anxiety Disorder (GAD) on both subjective and objective cognitive abilities in untreated LLD individuals.

METHODS

A total of 77 participants aged 60 years and above were recruited for this study, comprising 31 individuals with Major Depressive Disorder (LLD group), 46 with MDD and coexisting Generalized Anxiety Disorder (LLDA group), and 54 healthy controls (HC). Prior to the study, all patients had abstained from psychotropic medication for a minimum of two weeks. Comprehensive neuropsychological assessments were administered to all participants.

RESULTS

The LLDA group exhibited substantial disparities in memory, attention, processing speed,executive function,overall cognitive functioning, and subjective cognitive functioning when compared to the HC group. The LLD group displayed deficits in memory, SCWT-W in attention, SCWT-C in processing speed,overall cognitive functioning, and subjective cognitive functioning in comparison to the healthy controls. Although the LLD group achieved lower average scores in executive function, TMTA in processing speed, and DSST in attention than the HC group, no significant distinctions were identified between these groups in these domains. Linear regression analysis unveiled that anxiety symptoms had a significant impact on subjective cognitive deficits among MDD patients, but exhibited a milder influence on objective cognitive performance. After adjusting for the severity of depression, anxiety symptoms were found to affect TMTA in processing speed and subjective cognitive functioning in LLD patients.

CONCLUSION

Late-Life Depression (LLD) exhibits pervasive cognitive impairments, particularly in individuals with generalized anxiety disorder, presenting a crucial target for future therapeutic interventions. Among elderly individuals with depression, anxiety symptoms significantly impact subjective cognitive functioning, suggesting its potential utility in distinguishing between depression-associated cognitive decline and pre-dementia conditions.

Association of Depression With the Progression of Multimorbidity in Older Adults: A Population-Based Cohort Study

BACKGROUND

The relationship between depression and the risk of multimorbidity progression has rarely been studied in older adults. This study was aimed to determine whether depression is associated with progression in the severity and complexity of multimorbidity, considering the influence of depression's severity and subtype.

METHODS

As a part of the Korean Longitudinal Study on Cognitive Aging and Dementia, this population-based cohort study followed a random sample of community-dwelling Koreans aged 60 and older for 8 years at 2-year intervals starting in 2010. Participants included those who completed mood and multimorbidity assessments and did not exhibit complex multimorbidity at the study's outset. Depression was assessed using the Geriatric Depression Scale, while multimorbidity was evaluated using the Cumulative Illness Rating Scale. The study quantified multimorbidity complexity by counting affected body systems and measured multimorbidity severity by averaging scores across 14 body systems.

FINDINGS

The 2,486 participants (age = 69.1 ± 6.5 years, 57.6% women) were followed for 5.9 ± 2.4 years. Linear mixed models revealed that participants with depression had a faster increase in multimorbidity complexity score (β = .065, SE = 0.019, p = 0.001) than those without depression, but a comparable increase in multimorbidity severity score (β = .001, SE = .009, p = 0.870) to those without depression. Cox proportional hazard models revealed that depression was associated with the risk of developing highly complex multimorbidity affecting five or more body systems, particularly in severe or anhedonic depression.

INTERPRETATION

Depression was associated with the worsening of multimorbidity in Korean older adults, particularly when severe or anhedonic. Early screening and management of depression may help to reduce the burden of multimorbidity in older adults.

New insights into the effects of serotonin on Parkinson's disease and depression through its role in the gastrointestinal tract

Neuropsychiatric and neurodegenerative disorders are frequently associated with gastrointestinal (GI) co-pathologies. Although the central and enteric nervous systems (CNS and ENS, respectively) have been studied separately, there is increasing interest in factors that may contribute to conditions affecting both systems. There is compelling evidence that serotonin (5-HT) may play an important role in several gut-brain disorders. It is well known that 5-HT is essential for the development and functioning of the CNS. However, most of the body's 5-HT is produced in the GI tract. A deeper understanding of the specific effects of enteric 5-HT on gut-brain disorders may provide the basis for the development of new therapeutic targets. This review summarizes current data focusing on the important role of 5-HT in ENS development and motility, with particular emphasis on novel aspects of 5-HT signaling in conditions where CNS and ENS comorbidities are common, such as Parkinson's disease and depressive disorders.

Temporal dynamics of depressive symptoms and cognitive decline in the oldest old: dynamic time warp analysis of the Leiden 85-plus study

BACKGROUND

The prevalence of depressive symptoms and cognitive decline increases with age. We investigated their temporal dynamics in individuals aged 85 and older across a 5-year follow-up period.

METHODS

Participants were selected from the Leiden 85-plus study and were eligible if at least three follow-up measurements were available (325 of 599 participants). Depressive symptoms were assessed at baseline and at yearly assessments during a follow-up period of up to 5 years, using the 15-item Geriatric Depression Scale (GDS-15). Cognitive decline was measured through various tests, including the Mini Mental State Exam, Stroop test, Letter Digit Coding test and immediate and delayed recall. A novel method, dynamic time warping analysis, was employed to model their temporal dynamics within individuals, in undirected and directed time-lag analyses, to ascertain whether depressive symptoms precede cognitive decline in group-level aggregated results or vice versa.

RESULTS

The 325 participants were all 85 years of age at baseline; 68% were female, and 45% received intermediate to higher education. Depressive symptoms and cognitive functioning significantly covaried in time, and directed analyses showed that depressive symptoms preceded most of the constituents of cognitive impairment in the oldest old. Of the GDS-15 symptoms, those with the strongest outstrength, indicating changes in these symptoms preceded subsequent changes in other symptoms, were worthlessness, hopelessness, low happiness, dropping activities/interests, and low satisfaction with life (all P's < 0.01).

CONCLUSION

Depressive symptoms preceded cognitive impairment in a population based sample of the oldest old.

The Effect of Genetic Variations in the Vitamin D Receptor Gene on the Course of Depressive Symptoms

BACKGROUND

Evidence on the association between single nucleotide polymorphisms (SNPs) in the vitamin D receptor (VDR) and depressive symptoms is inconclusive.

OBJECTIVES

The primary aim of the study was to investigate the association between SNPs in the VDR gene and depressive symptoms.

METHODS

In a sample of older adults from the Longitudinal Ageing Study Amsterdam (n = 922), depressive symptoms were assessed using the Centre for Epidemiological Studies Depression scale (CES-D scale) at baseline and after 3, 6, and 10 y of follow-up. Blood samples for SNP and serum 25-hydroxyvitamin D3 (25(OH)D3) determination were obtained at baseline. The association between 13 SNPs in the VDR gene and the course of depressive symptoms were evaluated using linear mixed models. The interaction between SNPs and serum 25(OH)D3 in relation to depressive symptoms was evaluated using multiple linear regression.

RESULTS

No SNPs were associated with the course of depressive symptoms. Significant interactions between serum 25(OH)D3 and SNPs in the VDR gene were found. Stratified analysis revealed that within the GG genotype strata, 10 nmol/L higher serum 25(OH)D3 was associated with 0.27 (95% CI: -0.50, -0.04) and 0.23 (95% CI: -0.48, 0.02) lower scores on the CES-D scale for Cdx-2 and 1b-G-886A, respectively. This association was not found in persons having the GA or AA genotype.

CONCLUSIONS

No SNPs are associated with the course of depressive symptoms. Stratified analysis shows that the effect of serum 25(OH)D3 concentrations on depressive symptoms is different among genotypes of Cdx-2 and 1b-G-886A. Future research should elucidate on the function of Cdx-2 and 1b-G-886A to describe their effect.

A scoping review of functional near-infrared spectroscopy biomarkers in late-life depression: Depressive symptoms, cognitive functioning, and social functioning

Late-life depression is one of the most damaging mental illnesses, disrupting the normal lives of older people by causing chronic illness and cognitive impairment. Patients with late-life depression, accompanied by changes in appetite, insomnia, fatigue and guilt, are more likely to experience irritability, anxiety and somatic symptoms. It increases the risk of suicide and dementia and is a major challenge for the public health systems. The current clinical assessment, identification and effectiveness assessment of late-life depression are primarily based on history taking, mental status examination and scale scoring, which lack subjectivity and precision. Functional near-infrared spectroscopy is a rapidly developing optical imaging technology that objectively reflects the oxygenation of hemoglobin in different cerebral regions during different tasks and assesses the functional status of the cerebral cortex. This article presents a comprehensive review of the assessment of functional near-infrared spectroscopy technology in assessing depressive symptoms, social functioning, and cognitive functioning in patients with late-life depression. The use of functional near-infrared spectroscopy provides greater insight into the neurobiological mechanisms underlying depression and helps to assess these three aspects of functionality in depressed patients. In addition, the study discusses the limitations of previous research and explores potential advances in the field.

The influence of residential Environment and residential experience on psychological depression in older adults: Evidence from China and Europe

This cross-national study examined the influence of residential environment and experience on depression in older adults in China and Europe to address existing research gaps. Using data from the China Health and Retirement Longitudinal Study (CHARLS) and Survey of Health, Ageing, and Retirement in Europe (SHARE) and employing ridge regression, it was found that residential environment and experience have a significant influence on older adults' depression. The influence of residential experience aligns with the sensitivity period hypothesis. The environment in which older adults live during specific age periods leaves an imprint on their psyche. This imprint is activated when specific environments are encountered in old age, thereby influencing the level of depression. This study examined how their influence on depression contributes to understanding older adults' housing preferences and can guide housing-related policies.

Identifying data-driven subtypes of major depressive disorder with electronic health records

BACKGROUND

Efforts to reduce the heterogeneity of major depressive disorder (MDD) by identifying subtypes have not yet facilitated treatment personalization or investigation of biology, so novel approaches merit consideration.

METHODS

We utilized electronic health records drawn from 2 academic medical centers and affiliated health systems in Massachusetts to identify data-driven subtypes of MDD, characterizing sociodemographic features, comorbid diagnoses, and treatment patterns. We applied Latent Dirichlet Allocation (LDA) to summarize diagnostic codes followed by agglomerative clustering to define patient subgroups.

RESULTS

Among 136,371 patients (95,034 women [70 %]; 41,337 men [30 %]; mean [SD] age, 47.0 [14.0] years), the 15 putative MDD subtypes were characterized by comorbidities and distinct patterns in medication use. There was substantial variation in rates of selective serotonin reuptake inhibitor (SSRI) use (from a low of 62 % to a high of 78 %) and selective norepinephrine reuptake inhibitor (SNRI) use (from 4 % to 21 %).

LIMITATIONS

Electronic health records lack reliable symptom-level data, so we cannot examine the extent to which subtypes might differ in clinical presentation or symptom dimensions.

CONCLUSION

These data-driven subtypes, drawing on representative clinical cohorts, merit further investigation for their utility in identifying more homogeneous patient populations for basic as well as clinical investigation.