The longitudinal course of late-life depression remains under-studied.

To describe transitions along the depression continuum in old age and to identify factors associated with specific transition patterns.

We analysed 15-year longitudinal data on 2745 dementia-free persons aged 60+ from the population-based Swedish National Study on Aging and Care in Kungsholmen. Depression (minor and major) was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision; subsyndromal depression (SSD) was operationalised as the presence of ≥2 symptoms without depression. Multistate survival models were used to map depression transitions, including death, and to examine the association of psychosocial (social network, connection and support), lifestyle (smoking, alcohol consumption and physical activity) and clinical (somatic disease count) factors with transition patterns.

Over the follow-up, 19.1% had ≥1 transitions across depressive states, while 6.5% had ≥2. Each additional somatic disease was associated with a higher hazard of progression from no depression (No Dep) to SSD (hazard ratio 1.09; 1.07–1.10) and depression (Dep) (hazard ratio 1.06; 1.04–1.08), but also with a lower recovery (HRSSD−No Dep 0.95; 0.93–0.97 [where ‘HR’ refers to ‘hazard ratio’]; HRDep−No Dep 0.96; 0.93–0.99). Physical activity was associated with an increased hazard of recovery to no depression from SSD (hazard ratio 1.49; 1.28–1.73) and depression (hazard ratio 1.20; 1.00–1.44), while a richer social network was associated with both higher recovery from (HRSSD−No Dep 1.44; 1.26–1.66; HRDep−No Dep 1.51; 1.34–1.71) and lower progression hazards to a worse depressive state (HRNo Dep−SSD 0.81; 0.70–0.94; HRNo Dep−Dep 0.58; 0.46–0.73; HRSSD−Dep 0.66; 0.44–0.98).

Older people may present with heterogeneous depressive trajectories. Targeting the accumulation of somatic diseases and enhancing social interactions may be appropriate for both depression prevention and burden reduction, while promoting physical activity may primarily benefit recovery from depressive disorders.

Subthreshold depression (sD) negatively impacts well-being and psychosocial function and is more prevalent compared with major depressive disorder (MDD). However, as adults with sD are less likely to seek face-to-face intervention, internet-based cognitive-behavioral therapy (ICBT) may overcome barriers of accessibility to psychotherapy. Although several trials explored the efficacy of ICBT for sD, the results remain inconsistent. This study evaluated whether ICBT is effective in reducing depressive symptoms among Chinese adults with sD.

A randomized controlled trial was performed. The participants were randomly assigned to 5 weeks of ICBT, group-based face-to-face cognitive-behavioral therapy (CBT), or a waiting list (WL). Assessments were conducted at baseline, post-intervention and at a 6-month follow-up. The primary outcome measured depressive symptoms using the Center for Epidemiological Studies Depression Scale (CES-D). Outcomes were analyzed using a mixed-effects model to assess the effects of ICBT.

ICBT participants reported greater reductions on all the outcomes compared to the WL group at post-intervention. The ICBT group showed larger improvement on the Patient Health Questionnaire-9 (PHQ-9) at post-intervention (d = 0.12) and at follow-up (d = 0.10), and with CES-D at post-intervention (d = 0.06), compared to the CBT group.

ICBT is effective in reducing depressive symptoms among Chinese adults with sD, and improvements in outcomes were sustained at a 6-month follow-up. Considering the low rates of face-to-face psychotherapy, our findings highlight the considerable potential and implications for the Chinese government to promote the use of ICBT for sD in China.

Both morbidity and mortality are elevated for individuals with subsyndromal depression (SSD) compared to non-depression (ND) in those of younger ages, but scientific studies are scarce for very old individuals. The aim of this study was therefore to compare the morbidity and mortality in very old individuals with SSD and ND.

An 8-year prospective population-based study was undertaken on 85-year-old individuals in Sweden.

Data were collected from postal questionnaires and clinical assessments at baseline, after 1, 5, and 8 years. Depressive symptoms were measured with Geriatric Depression Scale and the results were classified into ND, SSD, and syndromal depression. Mortality was investigated using multivariable cox regressions, and variables of morbidity were investigated using linear mixed models.

Compared to ND, in people with SSD, mortality was elevated in the univariate regression, but this association vanished when controlling for relevant covariates. Morbidity was elevated with regard to basic activities of daily living (ADLs), instrumental ADLs, loneliness, self-perceived health, and depressive symptoms for individuals with SSD compared to ND, whereas cognitive speed, executive functions, and global cognitive function were not significantly impaired when adjusting for covariates.

SSD among very old individuals is longitudinally associated with elevated morbidity but not mortality, when controlling for relevant covariates. Considering the high prevalence of SSD and the demographic development of increasing numbers of very old people, the findings highlight the need to develop clinical and societal strategies to prevent SSD and associated negative outcomes.

We examined race differences in the DSM-IV clinical significance criterion (CSC), an indicator of depressive role impairment, and its impact on assessment outcomes in older white and black women with diagnosed and subthreshold depression.

We conducted a secondary analysis of a community-based interview study, using group comparisons and logistic regression.

Lower-income neighborhoods in a Midwestern city.

411 community-dwelling depressed and non-depressed women ≥ 65 years (45.3% Black; mean age = 75.2, SD = 7.2) recruited through census tract-based telephone screening.

SCID interview for DSM-IV to assess major depression and dysthymia; Center for Epidemiologic Studies-Depression Scale to define subthreshold depression (≥16 points); Mini-Mental State Examination, count of medical conditions, activities of daily living, and mental health treatment to assess health factors.

Black participants were less likely than Whites to endorse the CSC (11.8% vs. 24.1%; p = .002). There were few race differences in depressive symptom type, severity, or count. Blacks with subthreshold depression endorsed more symptoms, though this comparison was not significant after adjustments. Health factors did not account for race differences in CSC endorsement. Disregarding the CSC-eliminated differences in diagnosis rate, race was a significant predictor of CSC endorsement in a logistic regression.

Race differences in CSC endorsement are not due to depressive symptom presentations or health factors. The use of the CSC may lead to underdiagnosis of depression among black older adults. Subthreshold depression among Blacks may be more severe compared to Whites, thus requiring tailored assessment and treatment approaches.

Behavioural activation is an efficient treatment for depression and can improve intrinsic motivation. Previous studies have revealed that the frontostriatal circuit is involved in intrinsic motivation; however, there are no data on how behavioural activation affects the frontostriatal circuit.

We aimed to investigate behavioural activation-related changes in the frontostriatal circuit.

Fifty-nine individuals with subthreshold depression were randomly assigned to either the intervention or non-intervention group. The intervention group received five weekly behavioural activation sessions. The participants underwent functional magnetic resonance imaging scanning on two separate occasions while performing a stopwatch task based on intrinsic motivation. We investigated changes in neural activity and functional connectivity after behavioural activation.

After behavioural activation, the intervention group had increased activation and connectivity in the frontostriatal region compared with the non-intervention group. The increased activation in the right middle frontal gyrus was correlated with an improvement of subjective sensitivity to environmental rewards.

Behavioural activation-related changes to the frontostriatal circuit advance our understanding of psychotherapy-induced improvements in the neural basis of intrinsic motivation.

None.

Studies have consistently shown that subthreshold depression is associated with an increased risk of developing major depression. However, no study has yet calculated a pooled estimate that quantifies the magnitude of this risk across multiple studies.

We conducted a systematic review to identify longitudinal cohort studies containing data on the association between subthreshold depression and future major depression. A baseline meta-analysis was conducted using the inverse variance heterogeneity method to calculate the incidence rate ratio (IRR) of major depression among people with subthreshold depression relative to non-depressed controls. Subgroup analyses were conducted to investigate whether IRR estimates differed between studies categorised by age group or sample type. Sensitivity analyses were also conducted to test the robustness of baseline results to several sources of study heterogeneity, such as the case definition for subthreshold depression.

Data from 16 studies (n = 67 318) revealed that people with subthreshold depression had an increased risk of developing major depression (IRR = 1.95, 95% confidence interval 1.28–2.97). Subgroup analyses estimated similar IRRs for different age groups (youth, adults and the elderly) and sample types (community-based and primary care). Sensitivity analyses demonstrated that baseline results were robust to different sources of study heterogeneity.

The results of this study support the scaling up of effective indicated prevention interventions for people with subthreshold depression, regardless of age group or setting.

Studying secular trends in the exposure to risk and protective factors of depression and whether these trends are associated with secular trends in the prevalence of depression is important to estimate future healthcare demands and to identify targets for prevention.

Three birth cohorts of 55–64-year olds from the population-based Longitudinal Aging Study Amsterdam were examined using identical methods in 1992 (n = 944), 2002 (n = 964) and 2012 (n = 957). A two-stage screening design was used to identify subthreshold depression (SUBD) and major depressive disorder (MDD). Multinomial logistic regression analyses were used to identify secular trends in depression prevalence and to identify factors from the biopsychosocial domains of functioning that were associated with these trends.

Compared with 1992, MDD became more prevalent in 2002 (OR 1.90, 95% CI 1.10–3.28, p = 0.022) and 2012 (OR 1.80, 95% CI 1.03–3.14, p = 0.039). This was largely attributable to an increase in the prevalence of chronic diseases and functional limitations. Socioeconomic and psychosocial improvements, including an increase in labor market participation, social support and mastery, hampered MDD rates to rise more and were also associated with a 32% decline of SUBD-rates in 2012 as compared with 2002 (OR 0.68, 95% CI 0.48–0.96, p = 0.03).

Among late middle-aged adults, there is a substantial net increase of MDD, which is associated with deteriorating physical health. If morbidity and disability continue to increase, a further expansion of MDD rates may be expected. Improving socioeconomic and psychosocial conditions may benefit public health, as these factors were protective against a higher prevalence of both MDD and SUBD.

It has been demonstrated that negatively distorted self-referential processing, in which individuals evaluate one's own self, is a pathogenic mechanism in subthreshold depression that has a considerable impact on the quality of life and carries an elevated risk of developing major depression. Behavioural activation (BA) is an effective intervention for depression, including subthreshold depression. However, brain mechanisms underlying BA are not fully understood. We sought to examine the effect of BA on neural activation during other perspective self-referential processing in subthreshold depression.

A total of 56 subjects underwent functional magnetic resonance imaging scans during a self-referential task with two viewpoints (self/other) and two emotional valences (positive/negative) on two occasions. Between scans, while the intervention group (n = 27) received BA therapy, the control group (n = 29) did not.

The intervention group showed improvement in depressive symptoms, increased activation in the dorsal medial prefrontal cortex (dmPFC), and increased reaction times during other perspective self-referential processing for positive words after the intervention. Also, there was a positive correlation between increased activation in the dmPFC and improvement of depressive symptoms. Additionally, there was a positive correlation between improvement of depressive symptoms and increased reaction times.

BA increased dmPFC activation during other perspective self-referential processing with improvement of depressive symptoms and increased reaction times which were associated with improvement of self-monitoring function. Our results suggest that BA improved depressive symptoms and objective monitoring function for subthreshold depression.

Attention bias modification (ABM) training has been suggested to effectively reduce depressive symptoms, and may be useful in the prevention of the illness in individuals with subthreshold symptoms, yet little is known about the spontaneous brain activity changes associated with ABM training.

Resting-state functional MRI was used to explore the effects of ABM training on subthreshold depression (SubD) and corresponding spontaneous brain activity changes. Participants were 41 young women with SubD and 26 matched non-depressed controls. Participants with SubD were randomized to receive either ABM or placebo training during 28 sessions across 4 weeks. Non-depressed controls were assessed before training only. Attentional bias, depressive severity, and spontaneous brain activity before and after training were assessed in both training groups.

Findings revealed that compared to active control training, ABM training significantly decreased depression symptoms, and increased attention for positive stimuli. Resting-state data found that ABM training significantly reduced amplitude of low-frequency fluctuations (ALFF) of the right anterior insula (AI) and right middle frontal gyrus which showed greater ALFF than non-depressed controls before training; Functional connectivity strength between right AI and the right frontoinsular and right supramarginal gyrus were significantly decreased after training within the ABM group; moreover, the improvement of depression symptoms following ABM significantly correlated with the connectivity strength reductions between right AI and right frontoinsular and right supramarginal gyrus.

These results suggest that ABM has the potential to reshape the abnormal patterns of spontaneous brain activity in relevant neural circuits associated with depression.

Depressive symptoms are prominent psychopathological features of Huntington's disease (HD), making a negative impact on social functioning and well-being.

We compared the frequencies of a history of depression, previous suicide attempts and current subthreshold depression between 61 early-stage HD participants and 40 matched controls. The HD group was then split based on the overall HD group's median Hospital Anxiety and Depression Scale-depression score into a group of 30 non-depressed participants (mean 0.8, s.d. = 0.7) and a group of 31 participants with subthreshold depressive symptoms (mean 7.3, s.d. = 3.5) to explore the neuroanatomy underlying subthreshold depressive symptoms in HD using voxel-based morphometry (VBM) and diffusion tensor imaging (DTI).

Frequencies of history of depression, previous suicide attempts or current subthreshold depressive symptoms were higher in HD than in controls. The severity of current depressive symptoms was also higher in HD, but not associated with the severity of HD motor signs or disease burden. Compared with the non-depressed HD group DTI revealed lower fractional anisotropy (FA) values in the frontal cortex, anterior cingulate cortex, insula and cerebellum of the HD group with subthreshold depressive symptoms. In contrast, VBM measures were similar in both HD groups. A history of depression, the severity of HD motor signs or disease burden did not correlate with FA values of these regions.

Current subthreshold depressive symptoms in early HD are associated with microstructural changes – without concomitant brain volume loss – in brain regions known to be involved in major depressive disorder, but not those typically associated with HD pathology.

Depressive symptoms above screening thresholds have been shown to predict functional decline in older adults. Less is known about the impact of subthreshold depression, and whether more symptoms confer significantly greater risk compared to fewer symptoms.

Using data from the Duke Established Populations for Epidemiologic Studies of the Elderly (EPESE) collected over 10 years, we used repeated-measures mixed models to predict functional change by depression status at the prior (index) in-person interview. Depressive symptoms were measured using a modified version of the Center for Epidemiologic Studies Depression Scale (CES-D). Subthreshold depression was operationalized as 6–8 symptoms and CES-D-defined depression as 9–20 symptoms in the previous week. Three domains of functional status were assessed at the subsequent in-person interview: limitations in basic activities of daily living (ADL), instrumental ADL (IADL) and mobility.

Controlling for race, sex, age, education, marital status, cognitive status, health status, self-perceived health, perceived social support and functional status at the index interview, having ⩾6 depressive symptoms predicted an increase of 0.12 IADL limitations 3–4 years later (p=0.03). The incremental effect of CES-D-defined depression (⩾9 symptoms compared to 6–8 symptoms) was not significant, suggesting that the effect of more symptomatic depression did not add to that of subthreshold depression. CES-D score modeled as a continuous variable predicted functional change for all domains, but the relationship was not linear, supporting a possible threshold effect.

The relationship between depressive symptoms and functional change is complex, not necessarily linear, and may vary by tasks assessed.