Effectiveness of psychological interventions among community-dwelling older adults with subthreshold depression: A systematic review and meta-analysis

BACKGROUND

Little is known about the effectiveness of psychological interventions among older adults with subthreshold depression in the community. This systematic review and meta-analysis aimed to examine the effectiveness of psychological interventions on depressive symptoms, anxiety symptoms and quality of life.

METHODS

We searched five databases from inception to 20th September 2022 and included RCTs that evaluated the effectiveness of psychological interventions among older adults with subthreshold depression in the community. Standardized mean difference (SMD) and 95 % confidence intervals (CI) were used to calculate the effect sizes of treatment outcomes in the meta-analysis, using RevMan 5.4.1 and Stata 16.0.

RESULTS

This meta-analysis included thirteen RCT studies involving 2079 participants. Psychological interventions could significantly reduce depressive symptoms (post-intervention time: SMD = -0.58, 95 % CI = -0.76 to -0.40; follow-up time: SMD = -0.31, 95 % CI = -0.41 to -0.22) and anxiety symptoms (post-intervention time: SMD = -0.33, 95 % CI = -0.49 to -0.17; follow-up time: SMD = -0.24, 95 % CI = -0.36 to -0.12) and improve quality of life (post-intervention time: SMD = 0.30, 95 % CI = 0.05 to 0.55; follow-up time: SMD = 0.15, 95 % CI = 0.01 to 0.28).

CONCLUSION

Evidence suggests that psychological interventions could significantly reduce depressive symptoms and anxiety symptoms, and improve quality of life among community-dwelling older adults with subthreshold depression.

Perceived stress and brain connectivity in subthreshold depression: Insights from eyes-closed and eyes-open states

Perceived stress is an acknowledged risk factor for subthreshold depression (StD), and fluctuations in perceived stress are thought to disrupt the harmony of brain networks essential for emotional and cognitive functioning. This study aimed to elucidate the relationship between eye-open (EO) and eye-closed (EC) states, perceived stress, and StD. We recruited 27 individuals with StD and 33 healthy controls, collecting resting state fMRI data under both EC and EO conditions. We combined intrinsic connectivity and seed-based functional connectivity analyses to construct the functional network and explore differences between EC and EO conditions. Graph theory analysis revealed weakened connectivity strength in the right superior frontal gyrus (SFG) and right median cingulate and paracingulate gyrus (MCC) among participants with StD, suggesting an important role for these regions in the stress-related emotions dysregulation. Notably, altered SFG connectivity was observed to significantly relate to perceived stress levels in StD, and the SFG connection emerges as a neural mediator potentially influencing the relationship between perceived stress and StD. These findings highlight the role of SFG and MCC in perceived stress and suggest that understanding EC and EO states in relation to these regions is important in the neurobiological framework of StD. This may offer valuable perspectives for early prevention and intervention strategies in mental health disorders.

Characteristics of oxyhemoglobin during the verbal fluency task in subthreshold depression: A multi-channel near-infrared spectroscopy study

OBJECTIVE

Subthreshold depression is an essential precursor and risk factor for major depressive disorder, and its accurate identification and timely intervention are important for reducing the prevalence of major depressive disorder. Therefore, we used functional near-infrared spectroscopic imaging (fNIRS) to explore the characteristics of the brain neural activity of college students with subthreshold depression in the verbal fluency task.

METHODS

A total of 72 subthreshold depressed college students (SDs) and 67 healthy college students (HCs) were recruited, and all subjects were subjected to a verbal fluency task (VFT) while a 53-channel fNIRS device was used to collect the subjects' cerebral blood oxygenation signals.

RESULTS

The results of the independent samples t-test showed that the mean oxyhemoglobin in the right dorsolateral prefrontal (ch34, ch42, ch45) and Broca's area (ch51, ch53) of SDs was lower than that of HCs. The peak oxygenated hemoglobin of SDs was lower in the right dorsolateral prefrontal (ch34) and Broca's area (ch51, ch53).The brain functional connectivity strength was lower than that of HCs. Correlation analysis showed that the left DLPFC and Broca's area were significantly negatively correlated with the depression level.

CONCLUSION

SDs showed abnormally low, inadequate levels of brain activation and weak frontotemporal brain functional connectivity. The right DLPFC has a higher sensitivity for the differentiation of depressive symptoms and is suitable as a biomarker for the presence of depressive symptoms. Dysfunction in Broca's area can be used both as a marker of depressive symptoms and as a biomarker, indicating the severity of depressive symptoms.

Mindfulness-based intervention reduce interference of negative stimuli to working memory in individuals with subclinical depression: A randomized controlled fMRI study

Background

Individuals with subclinical depression are prone to major depression and experience emotional responses and attentional biases to negative stimuli.

Method

In a randomized controlled study (N = 42) using functional magnetic resonance imaging (fMRI), we examined the neurocognitive mechanisms behind mindfulness-based cognitive therapy (MBCT) combining loving-kindness meditation (LKM) on a group with subclinical depression compared with the relaxation group across emotional face n-back (EFNBACK) tasks and resting state. We also collected behavioral and self-reported data to confirm neurocognitive results.

Results

During EFNBACK, the MBCT+LKM group showed greater activation in the left lingual gyrus and right inferior lateral occipital cortex. During rest, the MBCT+LKM group demonstrated increased connectivity of the anterior cingulate cortex and right inferior lateral occipital cortex, right anterior insula and left precentral gyrus. From amplitude of low frequency fluctuation (ALFF) data, activity in brain regions associated with cognitive control decreased and activity in brain regions associated with sensorimotor increased.

Conclusion

These results suggest that MBCT+LKM alleviate depression for subclinical individuals through improving executive function when they face negative stimuli.

Brain network hierarchy reorganization in subthreshold depression

BACKGROUND

Hierarchy is the organizing principle of human brain network. How network hierarchy changes in subthreshold depression (StD) is unclear. The aim of this study was to investigate the altered brain network hierarchy and its clinical significance in patients with StD.

METHODS

A total of 43 patients with StD and 43 healthy controls matched for age, gender and years of education participated in this study. Alterations in the hierarchy of StD brain networks were depicted by connectome gradient analysis. We assessed changes in network hierarchy by comparing gradient scores in each network in patients with StD and healthy controls. The study compared different brain subdivisions if there was a different network. Finally, we analysed the relationship between the altered gradient scores and clinical characteristics.

RESULTS

Patients with StD had contracted network hierarchy and suppressed cortical range gradients. In the principal gradient, the gradient scores of default mode network were significantly reduced in patients with StD compared to controls. In the default network, the subdivisions of reduced gradient scores were mainly located in the precuneus, superior temporal gyrus, and anterior and posterior cingulate gyrus. Reduced gradient scores in the default mode network, the anterior and posterior cingulate gyrus were correlated with severity of depression.

CONCLUSIONS

The network hierarchy of the StD changed and was significantly correlated with depressive symptoms and severity. These results provided new insights into further understanding of the neural mechanisms of StD.

Modulatory effects of aerobic training on the degree centrality of brain functional activity in subthreshold depression

BACKGROUND

Aerobic training has been shown to effectively prevent the progression of depressive symptoms from subthreshold depression (StD) to major depressive disorder (MDD), and understanding how aerobic training promotes changes in neuroplasticity is essential to comprehending its antidepressant effects. Few studies, however, have quantified the alterations in spontaneous brain activity before and after aerobic training for StD.

METHODS

Participants included 44 individuals with StD and 34 healthy controls (HCs). Both groups underwent moderate aerobic training for eight weeks, and resting state functional magnetic resonance imaging (rs-fMRI) data were collected before and after training. The degree centrality (DC) changes between the two groups and the DC changes in each group before and after training were quantified.

RESULTS

The rs-fMRI results showed that compared with the HCs, the DC values of the StD group in the orbital region of the left inferior frontal gyrus significantly depreciated at baseline. After aerobic training, the results of the follow-up examination revealed no significant difference in the DC values between the two groups. In addition, compared with baseline, the StD group exhibited an significant decrease in the DC values of the left dorsolateral superior frontal gyrus; while the HCs group exhibited an significant decrease in the DC values of the left thalamus. No statistically significant connection was seen between changes in DC values and psychological scale scores in the StD group.

CONCLUSIONS

Our findings suggest that regular aerobic training can enhance brain plasticity in StD. In addition, we demonstrated that DC is a relevant and accessible method for evaluating the functional plasticity of the brain induced by aerobic training in StD.

Aberrant positive affect dynamics in individuals with subthreshold depression: Evidence from laboratory and real-world assessments

Background/Objective

Reduced positive affect (PA) is a core feature of major depressive disorder (MDD). However, the precursor of MDD, subthreshold depression (StD), has received less attention in this regard. Therefore, we examined PA dynamics in StD, integrating laboratory-based and ecological momentary assessment (EMA) approaches.

Method

Participants were college students recruited from Chinese universities (31 with StD, and 39 healthy controls (HC)). Positive mood was induced in the laboratory by an eight-minute comedy clip used to assess PA reactivity and maintenance. To extend findings to the real world and explore mechanisms of PA maintenance, 53 participants with StD and 64 HC reported their emotional states 14 times daily for one week via EMA. Multilevel models were used to test for predictors of PA inertia.

Results

In the laboratory, participants with StD achieved the same PA reactivity as HC when facing positive stimuli, yet the curve-fitting revealed difficulties for the StD group in maintaining PA over time. Such reduced capacity was further observed in real-world settings, manifesting in significantly greater PA inertia.

Conclusions

High PA inertia in daily life may reflect resistance to mood change in StD, explaining anhedonia and difficulties with emotional maintenance, and highlighting the need for early identification.

Altered EEG Microstates Dynamics in Individuals with Subthreshold Depression When Generating Negative Future Events

Negative bias in prospection may play a crucial role in driving and maintaining depression. Recent research suggests abnormal activation and functional connectivity in regions of the default mode network (DMN) during future event generation in depressed individuals. However, the neural dynamics during prospection in these individuals remain unknown. To capture network dynamics at high temporal resolution, we employed electroencephalogram (EEG) microstate analysis. We examined microstate properties during both positive and negative prospection in 35 individuals with subthreshold depression (SD) and 35 controls. We identified similar sets of four canonical microstates (A-D) across groups and conditions. Source analysis indicated that each microstate map partially overlapped with a subsystem of the DMN (A: verbal; B: visual-spatial; C: self-referential; and D: modulation). Notably, alterations in EEG microstates were primarily observed in negative prospection of individuals with SD. Specifically, when generating negative future events, the coverage, occurrence, and duration of microstate A increased, while the coverage and duration of microstates B and D decreased in the SD group compared to controls. Furthermore, we observed altered transitions, particularly involving microstate C, during negative prospection in the SD group. These altered dynamics suggest dysconnectivity between subsystems of the DMN during negative prospection in individuals with SD. In conclusion, we provide novel insights into the neural mechanisms of negative bias in depression. These alterations could serve as specific markers for depression and potential targets for future interventions.

Effects of the COVID-19 Pandemic on Depressive Symptoms, Including Clinical and Subthreshold Levels, and Eating Behaviors in First-Year University Students

Introduction

During the coronavirus disease 2019 (COVID-19) pandemic, university students experienced unusual environmental stresses, and the number of university students with depressive symptoms increased. The pandemic had a profoundly negative impact on the mental health of first-year students because they were not prepared to face academic and social stresses. The purpose of this study was to investigate the effect of the COVID-19 pandemic on depressive symptoms, eating behaviors, and stress-coping ability among first-year university students.

Methods

A total of 8,424 first-year students, 2,043 males and 1,636 females who entered university in Japan in 2021-2022 (during the pandemic) and 2,912 males and 1,833 females who entered university in Japan in 2018-2019 (before the pandemic), participated. We investigated the differences in depressive symptoms (using Beck Depression Inventory II [BDI-II]), eating behaviors (using Eating Attitudes Test-26 [EAT-26] and Bulimic Inventory Test, Edinburgh [BITE]), and stress coping (using Coping Inventory for Stressful Situations [CISS], which has three subscales) between first-year students before and during the pandemic. We divided the students into three categories (clinical, subthreshold, and nonsymptomatic) according to depressive symptoms and eating behaviors based on BDI-ll and EAT-26 scores and compared the frequencies of the three categories at two time points.

Results

First-year students during the pandemic showed a higher percentage of depressive symptoms, including clinical and subthreshold levels, than first-year students before the pandemic but did not show disordered eating behaviors. Additionally, the CISS task-oriented score was significantly lower for students with depressive symptoms, including clinical and subthreshold levels, during the pandemic than before the pandemic in females.

Conclusions

This study suggests that it may be important to provide first-year university students with more information about depressive symptom awareness, including clinical and subthreshold levels, and to provide appropriate ways for stress coping from many angles and early support in pandemic conditions.

Effect of Tai Chi on Young Adults with Subthreshold Depression via a Stress-Reward Complex: A Randomized Controlled Trial

BACKGROUND

Subthreshold depression is a highly prevalent mood disorder in young adults. Mind-body exercises, such as Tai Chi, have been adopted as interventions for clinical depressive symptoms. However, the possible effect and underlying mechanism of Tai Chi on subthreshold depression of young individuals remain unclear. This randomized controlled study aimed to evaluate the effects of Tai Chi training and tested the combined stress and reward circuitry model for subthreshold depression.

RESULTS

A total of 103 participants completed this trial, with 49 in the 12-week 24-style Tai Chi group and 54 participants in control group. Our results showed significantly lower scores on depressive symptoms (P = 0.002) and anxiety symptoms (P = 0.009) and higher scores on quality of life (P = 0.002) after Tai Chi training. There were significant reductions in salivary cortisol levels (P = 0.007) and putamen gray matter volume (P < 0.001) in the Tai Chi group. The changes in cortisol levels and putamen gray matter volume had direct (bootstrapping confidence interval [- 0.91, - 0.11]) and indirect effects (bootstrapping confidence interval [- 0.65, - 0.19]) on the changes induced by Tai Chi training on depressive symptoms, respectively.

CONCLUSION

The stress-reward complex results indicated an interaction between lowering stress levels and increasing reward circuitry activity associated with the alleviation of depressive symptoms among participants. The 12-week Tai Chi training was effective in improving the symptoms and quality of life of young adults with subthreshold depression. Trial Registration Chinese Registry of Clinical Trials (Registration Number: ChiCTR1900028289, Registered December 12, 2019).

Effects of non-pharmacological interventions on depressive symptoms and risk of major depressive disorder in adults with subthreshold depression: A systematic review and meta-analysis

Subthreshold depression (StD) is a condition that significantly reduces the quality of life and increases the risk of developing major depressive disorder (MDD). In order to investigate the effectiveness of non-pharmacological interventions (NPIs) in preventing the onset of MDD and improving depressive symptoms in adults with StD (AStDs), we conducted a systematic search of nine databases and included a total of 15 studies. Standardized mean differences (SMDs) were calculated using random effects models. RoB2 tool and GRADEpro software were used to assess the methodological quality and evidence. Funnel plots, Egger's, and Begg's tests were used to analyze publication bias. Sensitivity, subgroup and meta-regression analyses were performed to explore potential sources of heterogeneity. The results showed that NPIs had a significant effect in preventing the onset of MDD and improving depressive symptoms. Subgroup analysis revealed that NPIs were particularly effective in general adult populations, during short-term follow-up (FU) periods, among pregnant women, and in universal prevention programs. The results were found to be robust and credible, as they were less sensitive to changes in the analysis method. Timely detection and treatment of StD is feasible and important, as it can effectively delay or prevent the onset of MDD.

Sex differences in subjective cognitive impairment and clinical correlates in Chinese patients with subthreshold depression

OBJECTIVE

Subthreshold depression (SD) is a global mental health problem given its high prevalence, comorbidity, functional impairment, and its association with increased service utilization. However, currently little is known about sex differences of SD in cognitive impairment with clinical correlates. This study aims to explore sex differences in subjective cognitive impairment and clinically associated risk factors in Chinese patients with subthreshold depression (SD).

METHODS

A total of 126 patients with SD, 40 males and 86 females, aged 18-45 years, were included in this cross-sectional observational study. Their general information, psychological assessments, and psychiatric symptom assessments were collected online. The Patient Health Questionnaire depression-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), Perceived Deficits Questionnaire-Depression (PDQ-D), and Toronto Alexithymia Scale (TAS-20) with 3 subdomains were used. The obtained scores were analyzed with partial correlation and multiple linear regression analysis models.

RESULTS

Our results showed that females had significantly higher PDQ-D-20 total score than males. However, the differences in TAS-20 and subdomain score according to sex were not significant. Notably, TAS-20 and DDF (difficulty describing feelings) subdomain contributed to cognitive impairment in males, whereas both PHQ-9 total score and TAS-20 or DDF subdomain contributed to cognitive impairment in females.

CONCLUSION

These findings revealed significant sex differences in cognitive impairment and clinical correlates in SD, which should be further followed-up in the future.

Exercise effect on the gut microbiota in young adolescents with subthreshold depression: A randomized psychoeducation-controlled Trial

This 3-month randomized psychoeducation-controlled trial (RCT) of exercise was undertaken in young adolescents with subthreshold depression to examine the impact on gut microbiota. Participants (aged 12-14 years) were randomly assigned to an exercise or a psychoeducation-controlled group. The exercise intervention arm took moderate-intensity exercise, comprised of 30 min of running per day, 4 days a week for 3 months. Psychoeducation intervention consisted of 6 sessions of group activity including gaming, reading, and singing. The gut microbiota was assessed by metagenomic sequencing. After 3-month moderate-intensity exercise, the intervention group increased the relative abundance of Coprococcus, Blautia, Dorea, Tyzzerella at the genus level, as well as Tyzzerella nexilis, Ruminococcus obeum at species level when compared to the psychoeducation-controlled group. Moreover, EggNOG analyses showed that the defense and signal transduction mechanism were highly enriched after the active intervention, and changes were correlated with improvements in depressive symptoms measured by Chinese Patient Depression Questionnaire 9. The KEGG pathway of neurodegenerative diseases was depleted in the microbiome in young adolescents with subthreshold depression after exercise intervention. This 3-month RCT suggests that at both the genus and species levels, aerobic group exercise intervention improved in depressive symptoms and revealed changes in gut microbiota suggesting beneficial effects.

Nonpharmacological interventions for subthreshold depression in adults: A systematic review and network meta-analysis

Subthreshold depression (StD) is very common, with an estimated global incidence of 25%, and is associated with other clinical conditions. Nonpharmacological interventions have been demonstrated to be effective, but which one is best should be further investigated. This study aims to compare and rank the efficacy of nonpharmacological interventions in adults with StD. Ten databases were searched, and comparisons were made using a random-effects network meta-analysis using the frequentist framework. The assumption of local consistency was assessed by using the node-splitting method. The surface under the cumulative ranking curve (SUCRA) was used to separately rank each intervention. A total of 32 randomized controlled trials (RCTs) were included. The results showed that psychotherapy, as an intervention class, had significantly positive effects compared to control groups (SMD = -0.78, 95% CI: -1.06, -0.49) and had the highest rank (SUCRA, 79.0%; mean rank, 1.6). Cognitive behavioral therapy (CBT), as an individual intervention, had significantly positive effects relative to all control groups and had the highest rank (SUCRA, 82.5%; mean rank, 3.1). We speculate that psychotherapy, especially CBT, may be the most effective nonpharmacological intervention to improve StD in adults. More RCTs examining the efficacy of different nonpharmacological interventions are needed.

Impact of cognitive-affective and somatic symptoms in subthreshold depression transition in adults: Evidence from Depression Cohort in China (DCC)

BACKGROUND

Symptoms of subthreshold depression may differentially affect the illness transition. We examined the impact of cognitive-affective and somatic symptoms on different subthreshold depression transitions as well as risk factors influencing the aforementioned symptoms changes.

METHODS

Adults with subthreshold depression in the Depression Cohort in China were enrolled. Data collection was conducted at baseline, 6 and 12 months from 2019 to 2020. Cognitive-affective and somatic symptoms were assessed using the Patient Health Questionnaire-9. A total of 993 participants completed 12-month follow-up and were divided into persistent, intermittent and remission groups according to change in depressive symptoms. The longitudinal change of cognitive-affective and somatic symptoms in the three groups, as well as risk factors was analyzed using the generalized linear mixed-model.

RESULTS

There were 24.07 %, 34.04 % and 41.89 % of participants proceeding into persistent, intermittent and remission subthreshold depression groups, respectively. Cognitive-affective symptoms were the core symptoms for predicting the deterioration in persistent subthreshold depression (t = 2.48, P = 0.013), whereas somatic symptoms improved over time (t = -2.82, P = 0.005). Anxiety symptoms were the primary risk factors for worsening cognitive-affective symptoms (P < 0.001), following by insomnia symptoms, age, marital status, resilience and social functions. Somatic symptoms were affected by insomnia symptoms, anxiety symptoms and Body Mass Index successively.

LIMITATIONS

Major Depressive Episode was not explored in follow-up.

CONCLUSION

Cognitive-affective symptoms in subthreshold depression are at greater risk of illness deterioration. Future studies should endeavor to identify specific risk factors in different symptoms to forestall the transition from subthreshold to Major Depressive Disorder.

Gray and white matter structural examination for diagnosis of major depressive disorder and subthreshold depression in adolescents and young adults: a preliminary radiomics analysis

BACKGROUND

Radiomics is an emerging image analysis framework that provides more details than conventional methods. In present study, we aimed to identify structural radiomics features of gray matter (GM) and white matter (WM), and to develop and validate the classification model for major depressive disorder (MDD) and subthreshold depression (StD) diagnosis using radiomics analysis.

METHODS

A consecutive cohort of 142 adolescents and young adults, including 43 cases with MDD, 49 cases with StD and 50 healthy controls (HC), were recruited and underwent the three-dimensional T1 weighted imaging (3D-T1WI) and diffusion tensor imaging (DTI). We extracted radiomics features representing the shape and diffusion properties of GM and WM from all participants. Then, an all-relevant feature selection process embedded in a 10-fold cross-validation framework was used to identify features with significant power for discrimination. Random forest classifiers (RFC) were established and evaluated successively using identified features.

RESULTS

The results showed that a total of 3030 features were extracted after preprocessing, including 2262 shape-related features from each T1-weighted image representing GM morphometry and 768 features from each DTI representing the diffusion properties of WM. 25 features were selected ultimately, including ten features for MDD versus HC, eight features for StD versus HC, and seven features for MDD versus StD. The accuracies and area under curve (AUC) the RFC achieved were 86.75%, 0.93 for distinguishing MDD from HC with significant radiomics features located in the left medial orbitofrontal cortex, right superior and middle temporal regions, right anterior cingulate, left cuneus and hippocampus, 70.51%, 0.69 for discriminating StD from HC within left cuneus, medial orbitofrontal cortex, cerebellar vermis, hippocampus, anterior cingulate and amygdala, right superior and middle temporal regions, and 59.15%, 0.66 for differentiating MDD from StD within left medial orbitofrontal cortex, middle temporal and cuneus, right superior frontal, superior temporal regions and hippocampus, anterior cingulate, respectively.

CONCLUSION

These findings provide preliminary evidence that radiomics features of brain structure are valid for discriminating MDD and StD subjects from healthy controls. The MRI-based radiomics approach, with further improvement and validation, might be a potential facilitating method to clinical diagnosis of MDD or StD.

Is subthreshold depression in adolescence clinically relevant?

BACKGROUND

Subthreshold depression is highly prevalent in adolescence, but compared to major depressive disorder, the clinical impact is under-researched. The aim of this review was to compare subthreshold depression and major depressive disorder in adolescents by reviewing available literature on epidemiology, risk factors, illness trajectories, brain anatomy and function, genetics, and treatment response.

METHODS

We conducted a scoping review of papers on subthreshold depression and major depressive disorder in adolescence published in English. Studies in adults were included when research in adolescence was not available.

RESULTS

We found that individuals with subthreshold depression were similar to individuals with major depressive disorder in several regards, including female/male ratio, onset, functional impairment, comorbidity, health care utilization, suicidal ideation, genetic predisposition, brain alterations, and treatment response. Further, subthreshold depression was about two times more common than major depressive disorder.

LIMITATIONS

The definition of subthreshold depression is highly variable across studies. Adolescent-specific data are limited in the areas of neurobiology and treatment.

CONCLUSIONS

The findings of the current review support the idea that subthreshold depression is of clinical importance and provide evidence for a spectrum, versus categorical model, for depressive symptomatology. Given the frequency of subthreshold depression escalating to major depressive disorder, a greater recognition and awareness of the significance of subthreshold depression in research, clinical practice and policy-making may facilitate the development and application of early prevention and intervention.

A scoping review

Purpose: In diagnostic systems (e.g., DSM-5, ICD-10), depression is defined categorically. However, the concept of subthreshold depression (SD) has gained increasing interest in recent years. The purpose of the present paper was to review, based on a scoping review, the relevant papers in this field published between October 2011 and September 2020.Materials and methods: Of the 1,160 papers identified, 64 records could be included in further analysis. The scoping review was conducted using both electronic and manual methods.Results: The main result of the analysis is that the operationalisation criteria used are highly heterogeneous, which also leads to very heterogenous epidemiological data.Conclusions: Clear conclusions are not possible scrutinising the reported results. Most definitions seem to be arbitrary, with considerable overlap (e.g., between SD and minor depression). The review also revealed that the impact of SD on quality of life and related parameters appear to be in the range of the respective impact of major depression (MD) and therapeutic approaches might be helpful for SD and also for the prevention of conversion from SD to MD. Keeping the presented difficulties in mind, a proposal for the definition of SD is made in the present paper in order to facilitate the discussion leading to more homogeneous criteria.

Subthreshold lifetime depression and anxiety are associated with increased lifetime suicide attempts: A Korean nationwide study

BACKGROUND

Subthreshold depression and anxiety are highly prevalent and known to be associated with functional limitations and future onset of major depression or anxiety disorders. However, studies regarding suicidality at subthreshold levels of depression and anxiety are limited.

METHODS

A total of 17,639 Koreans aged from 18 to 64 responded to the Korean version of the WHO-composite international diagnostic interview (K-CIDI) version 2.1 between 2006 and 2016. Prevalence of subthreshold depression and anxiety, and information on lifetime suicide attempt (SA) were assessed. Multivariable logistic regression was performed to calculate the risk of SA by the level of depression or anxiety.

RESULTS

The risk of lifetime SA increased incrementally according to the level of depression and anxiety. In the subthreshold depression group, individuals with subthreshold anxiety increased the odds about threefold (OR = 3.15, 95% CI 3.12-3.18) and the threshold anxiety disorder group increased the odds about fivefold (OR = 5.33, 95% CI 5.27-5.38) for SA, compared to the group without any level of anxiety. In threshold depressive disorder, the subthreshold anxiety group showed about 1.8-fold higher odds (OR = 1.76, 95% CI 1.75-1.77) and the threshold anxiety disorder group showed threefold higher odds (OR = 2.93, 95% CI 2.92-2.95) for SA compared to the group without any level of anxiety.

CONCLUSIONS

Subthreshold levels of depression and anxiety were prevalent among Koreans and were associated with an increased prevalence of lifetime SA. A detailed assessment of depression and anxiety symptoms according to their level should be performed on a diagnostic continuum to prevent suicide.

The feasibility and acceptability of a brief psychological intervention for adults with long-term health conditions and subthreshold depression delivered via community pharmacies: a mixed methods evaluation-the Community Pharmacies Mood Intervention Study (CHEMIST)

BACKGROUND

Adults with long-term health conditions (LTCs) are more likely to experience depressive symptoms which can worsen health outcomes and quality of life, and increase healthcare costs. Subthreshold depression may go undetected and/or untreated. The Community Pharmacies Mood Intervention Study (CHEMIST) explored whether community pharmacies represent a suitable setting to offer brief psychological support to people with LTCs and comorbid subthreshold depression.

METHODS

A feasibility intervention study with a nested mixed methods evaluation was employed. Adults with subthreshold depression and a minimum of one LTC were recruited from community pharmacies/local general practices and offered a brief psychological support intervention ('Enhanced Support Intervention' (ESI)), based on behavioural activation within a Collaborative Care framework. The intervention included up to six sessions supported by pharmacy staff ('ESI facilitators') trained to deliver the ESI within the community pharmacy setting. Recruitment, retention rates and engagement with the ESI were assessed. Semi-structured, one-to-one interviews with pharmacy staff and study participants, and a focus group with pharmacy staff, explored experiences and acceptability of the study and the ESI. Themes were mapped onto constructs of the Theoretical Framework of Acceptability.

RESULTS

Recruitment of ESI participants was challenging and slower than anticipated despite the varied methods of recruitment employed; although, this was useful in identifying barriers and enabling factors for participation. Engagament with the ESI was good with n=17 (71%) recruited participants commencing the ESI. The ESI was found to be acceptable to participants and ESI facilitators. Retention rate at 4 months was good n=20 (87.0%). The main barriers to identifying potential participants for pharmacy staff were lack of time, resources and limited experience in research. The ESI training and support manual were acceptable to ESI facilitators. The ESI and supporting patient workbook were acceptable to people with LTCs and subthreshold depression.

CONCLUSIONS

Community pharmacies were viewed as an acceptable setting in which to deliver preventative brief psychological support to people with LTCs at risk of depression. This feasibility study provided important data to inform the design of a pilot randomised controlled trial in this setting and highlighted important considerations for future pharmacy-based research.

TRIAL REGISTRATION

ISRCTN11290592.

Amplitude of low-frequency fluctuation (ALFF) alterations in adults with subthreshold depression after physical exercise: A resting-state fMRI study

BACKGROUND

Physical exercise has been proved to reduce the risk of major depression in Subthreshold depression (StD) individuals effectively, yet little is known about the spontaneous brain activity changes associated with physical exercise.

METHODS

A total of 70 adult subjects, including 38 StD and 32 healthy control (HC) subjects, underwent a resting-state functional magnetic resonance imaging (rs-fMRI) before and after eight-week aerobic exercise respectively. Then, the amplitude of low-frequency fluctuation (ALFF) alterations between the two groups were quantitatively analyzed.

RESULTS

Before exercise intervention, the rs-fMRI data showed increased ALFF of the right putamen in the StD group compared with HC group. After exercise intervention, there was no significant ALFF change observed between the StD and HC groups. The longitudinal ALFF differences from pre- to post- exercise intervention showed significantly decreased ALFF in the right middle and inferior occipital gyrus, right middle and inferior temporal gyrus, right fusiform gyrus (FG), while increased ALFF in the right middle cingulate, right superior parietal louble, right inferior parietal lobule (IPL) (inferior parietal gyrus and supramarginal gyrus), and bilateral precuneus in the StD group. As for HC group, the results showed that decreased ALFF in the right FG and right parahippocampus, while increased ALFF in the right precuneus, right middle cingulate, right supplementary motor area, right superior parietal lobule and right paracentral lobule in the HC group. No significant correlation between changes of ALFF and clinical scale scores in the StD group.

LIMITATIONS

The definitions of StD are varied in terms of different studies, the final sample size was relatively small, and the age range of the subjects in this study was narrow. Meanwhile, the exercise intervention trial was short-term.

CONCLUSIONS

These results further support the standpoint that physical exercise has the potential to reshape the abnormal patterns of spontaneous brain activity in adults with StD.

Group and sex differences in social cognition in bipolar disorder, schizophrenia/schizoaffective disorder and healthy people

BACKGROUND

Impairment of social cognition is documented in bipolar disorder (BD) and schizophrenia/schizoaffective disorder (SCH). In healthy individuals, women perform better than men in some of its sub-domains. However, in BD and SCH the results are mixed. Our aim was to compare emotion recognition, affective Theory of Mind (ToM) and first- and second-order cognitive ToM in BD, SCH and healthy subjects, and to investigate sex-related differences.

METHODS

120 patients (BD = 60, SCH = 60) and 40 healthy subjects were recruited. Emotion recognition was assessed by the Pictures of Facial Affect (POFA) test, affective ToM by the Reading the Mind in the Eyes Test (RMET) and cognitive ToM by several false-belief stories. Group and sex differences were analyzed using parametric (POFA, RMET) and non-parametric (false-belief stories) tests. The impact of age, intelligence quotient (IQ) and clinical variables on patient performance was examined using a series of linear/logistic regressions.

RESULTS

Both groups of patients performed worse than healthy subjects on POFA, RMET and second-order false-belief (p < 0.001), but no differences were found between them. Instead, their deficits were related to older age and/or lower IQ (p < 0.01). Subthreshold depression was associated with a 6-fold increased risk of first-order false-belief failure (p < 0.001). Sex differences were only found in healthy subjects, with women outperforming men on POFA and RMET (p ≤ 0.012), but not on first/second-order false-belief.

LIMITATIONS

The cross-sectional design does not allow for causal inferences.

CONCLUSION

BD and SCH patients had deficits in emotion recognition, affective ToM, and second-order cognitive ToM, but their performance was comparable to each other, highlighting that the differences between them may be subtler than previously thought. First-order cognitive ToM remained intact, but subthreshold depression altered their normal functioning. Our results suggest that the advantage of healthy women in the emotional and affective aspects of social cognition would not be maintained in BD and SCH.

Orbitofrontal and Cingulate Thickness Asymmetry Associated with Depressive Symptom Dimensions

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

Neural extracellular vesicle-derived miR-17 in blood as a potential biomarker of subthreshold depression

Subthreshold depression (StD) is a depressive state that does not fulfil the criteria for major depressive disorder (MDD); however, StD has a risk for progression to MDD, and early intervention is therefore needed. Recently, a method for extracting neural extracellular vesicles (NEVs) excreted from neural cells of the brain from blood has been established, and microRNAs (miRNAs) encapsulated in NEVs are attracting interest because of their potential correlation to the pathogenesis of psychiatric disorders. However, miRNAs closely related to StD are still unknown. Therefore, to try to identify miRNAs closely related to the degree of StD, we examined the correlations between expression levels of some candidate miRNAs in NEVs and Patient Health Questionnaire-9 (PHQ-9) scores in subjects. Total RNAs in NEVs were extracted from serum of young adult males who had PHQ-9 scores of less than 10 (n = 9). Expression levels of eight miRNAs that were previously reported to be depression-associated miRNAs (let-7a-5p, miR-17-5p, miR-26b-5p, miR-34a-5p, miR-132-3p, miR-182-5p, miR-212-3p, and miR-1202) were measured using real-time PCR. Two of the eight miRNAs (miR-17-5p and miR-26b-5p) were stably detected. The relative expression levels of miR-17-5p showed a significant positive correlation with PHQ-9 scores (r = 0.85, p < 0.01), while those of miR-26b-5p showed no significance. Although a larger-scale analysis is needed due to the small number of subjects, these findings suggest that miR-17-5p in NEVs is a potential biomarker for StD.

Impact of subthreshold depression on health-related quality of life in patients with Parkinson's disease based on cognitive status

BACKGROUND

In patients with Parkinson's disease (PD), depression has a strong impact on quality of life (QoL). However, little is known about the influence of subthreshold depression (STD) on QoL in PD patients.

METHODS

A total of 230 hospitalized PD patients with normal and impaired cognitive status were included in this observational study. We collected the following data for analysis: Beck Depression Inventory level, Montreal Cognitive Assessment (MOCA) score, non-motor symptoms questionnaire score, PD questionnaire-39 (PDQ-39) score, Hoehn-Yahr stage, and Movement Disorder Society-sponsored revision of the unified PD rating scale III (MDS-UPDRS III) score. To study the impact of STD on the PDQ-39 summary index (SI) and its domains, we used multivariate analysis of variance and multivariate analysis of covariance.

RESULTS

In this cohort, 80 (34.8%) patients had STD [44 (32.3%) with high MOCA score (> 21) and 36 (38.3%) with low MOCA score (< 21)]. In PDQ-39 SI, there was a significant effect on depression level. In patients with higher MOCA score, STD was associated with worse PDQ-39 domains emotional well-being and cognition, whereas in patients with lower MOCA score, STD had no significant effect on PDQ-39 SI or its subdomains.

CONCLUSION

In PD patients, QoL is significantly affected by STD, and thus, more attention in medical care should be focused on treating STD. However, the impact is only observable in PD patients with normal cognitive function. STD patients show more reduced QoL than non-depressed patients, indicating that STD should be treated as a transition zone between normal mood and depression.

Effects of video viewing smartphone application intervention involving positive word stimulation in people with subthreshold depression: A pilot randomized controlled trial

BACKGROUND

A smartphone application (i.e., SPSRS) was developed to help people with subthreshold depression (StD) improve depressive symptoms by presenting positive word stimuli in videos. However, to date, no randomized controlled trials (RCTs) were conducted to investigate SPSRS application interventions for depressive symptoms in people with StD. Therefore, a pilot RCT was conducted to assess the preliminary efficacy of the SPSRS application intervention for people with StD.

METHODS

In a pilot RCT, 32 participants (female = 34.4%, mean age = 20.06, SD = 1.24) with StD were randomized to SPSRS application intervention for approximately 10 min/a day for 5 weeks (experimental group; n = 16) or no intervention (wait list control group; n = 16). The primary outcome is the change from baseline in the Center for Epidemiologic Studies Depression Scale (CES-D) score after the 5-week intervention. The secondary outcomes are the change from baseline in the Kessler Screening Scale for Psychological Distress (K-6) score and the Generalized Anxiety Disorder 7-item scale (GAD-7) after the 5-week intervention.

RESULTS

No participants dropped out of the study. The experimental group displayed medium, small, and small improvements in CES-D, K-6, and GAD-7 scores (adjusted Hedge's g = -0.64, -0.29, and -0.40), respectively, compared with control.

LIMITATIONS

The observed effects must be considered preliminary due to the small sample size.

CONCLUSIONS

The results suggest the potential of intervention using the SPSRS application to reduce depressive symptoms in people with StD. Future studies should replicate these findings in a full-scale RCT.

The effectiveness of Tai Chi on the depressive symptom of young adults with subthreshold depression: a study protocol for a randomized controlled trial

BACKGROUND

Depression is seriously affecting the physical and mental health of young people worldwide. Subthreshold depression, as an early stage of depression, is essential for early prevention and treatment of depression. Tai Chi, as a traditional Chinese mind-body therapy, may become an alternative intervention. However, the neurophysiological mechanism of Tai Chi for young people with subthreshold depression remains unclear, restricting its further promotion and application. Therefore, rigorous randomized clinical trials are needed to further observe the intervention effect of Tai Chi on young adults with subthreshold depression and explore the neurophysiological mechanism.

METHOD/DESIGN

This report describes a two-arm, randomized, parallel controlled trial with allocation concealment and assessor blinding. A total of 64 eligible participants are randomly allocated to the Tai Chi group and the waiting list group in a 1:1 ratio. Participants in the Tai Chi group receive 12 weeks of Tai Chi training, with a total of 36 times and each for 60 min. Specifically, the participants in the waiting list group are requested to maintain their routine lifestyle. In this study, the primary outcome measure is the mean change in scores on the PHQ-9 and HAMD-17 between baseline and 12 weeks; the secondary outcomes are the mean change in the scores on CES-D, CPSS, GAD-7, and PSQI. Besides, the saliva cortisol levels and fMRI are monitored to explore the mechanism of action of Tai Chi on subthreshold depression.

DISCUSSION

The protocol uses a randomized controlled trial to examine the effectiveness of Tai Chi for young adults with subthreshold depression and explore neurophysiological mechanisms. If the test results are positive, it can be verified that Tai Chi can promote the physical and mental health of young adults with subthreshold depression.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR1900028289 . Registered on 17 December 2019.

Lower recognition thresholds for sad facial expressions in subthreshold depression: a longitudinal study

Subthreshold depression (StD) is more prevalent than major depressive disorder (MDD) all over the world. Previous studies have indicated that depression is associated with impaired perception of facial expressions. However, for individuals with StD, whether perceptual sensitivity toward facial expressions could be altered and whether these alterations could stabilize over time remain largely unknown. Using the QUEST psychometric procedure, here we assessed recognition thresholds of five facial expressions (angry, fear, happy, sad and neutral) for individuals with StD and non-depressed controls. These subjects were retested after approximately 2-month time intervals. At the initial assessment, individuals with StD demonstrated lower recognition thresholds (i.e., stronger sensitivity) for only sadness compared to non-depressed controls. At the follow-up assessment, we classified the StD group as two subgroups: the non-remitted and the remitted group. For the former, lower recognition thresholds for only sadness were again found; for the latter, there was no significant difference. More importantly, individuals displaying lower recognition thresholds for sadness at the initial assessment were less likely to improve in depressive symptoms at the follow-up assessment. These results indicate that the alteration of perceptual sensitivity toward the sad expression for individuals with StD is associated with the current clinical state.

Efficacy of light therapy for a college student sample with non-seasonal subthreshold depression: An RCT study

BACKGROUND

Light therapy has been successfully used to treat seasonal and non-seasonal depression, but there is limited evidence for its efficacy in subthreshold depression. This study examines the efficacy of light therapy for symptoms of depression and anxiety in non-seasonal subthreshold depression.

METHODS

College students with non-seasonal subthreshold depression were recruited. The participants were randomly allocated to one of the three conditions: high- (LT-5000 lux) and low-intensity (LT-500 lux) light therapy conditions and a waiting-list control condition (WLC). The primary outcome was Hamilton Depression Rating Scale (HAMD), and secondary outcomes were Beck Depression Inventory-II (BDI-II) and state anxiety inventory (SAI), which were assessed at baseline (Week 0), during the trial (Week 4), and after completion of the light therapy (Week 8).

RESULTS

A total of 142 participants completed the trial. The LT-5000 (effect size [d] = 1.56, 95% CI: 1.15 to 1.98) and LT-500 conditions (d = 0.84, 95% CI: 0.43 to 1.26) were significantly superior to the WLC condition. For the LT-5000, LT-500, and WLC conditions by the end of the 8-week trial, a response on the HAMD was achieved by 70.0%, 42.0% and 19.0% of the participants, and remission was achieved by 76.0%, 54.0%, and 19.0%, respectively.

LIMITATIONS

The subjects were not followed up regularly after completion of the trial.

CONCLUSION

Light therapy, both at high- and low-intensity, was efficacious in the treatment of college students with non-seasonal subthreshold depression. High-intensity light therapy was superior to low-intensity light therapy by the end of an 8-week trial.

Depression and Cognitive Control across the Lifespan: a Systematic Review and Meta-Analysis

Depression has been shown to negatively impact neurocognitive functions, particularly those governed by fronto-subcortical networks, such as executive functions. Converging evidence suggests that depression-related executive dysfunction is greater at older ages, however, this has not been previously confirmed by meta-analysis. We performed a systematic review and meta-analysis, using three-level models, on peer-reviewed studies that examined depression-related differences in cognitive control in healthy community-dwelling individuals of any age. We focused on studies of cognitive control as defined by the National Institute of Mental Health (NIMH) Research Domain Criteria (RDoC) framework, which centers on goal-directed behavior, such as goal selection (updating, representations, maintenance), response selection (inhibition or suppression), and performance monitoring. In 16,806 participants aged 7 to 97 across 76 studies, both clinical depression and subthreshold depressive symptoms were associated with cognitive control deficits (Hedges' g = -0.31). This relationship was stronger in study samples with an older mean age. Within studies with a mean age of 39 years or higher, which represents the median age in our analyses, the relationship was stronger in clinical compared to subthreshold depression and in individuals taking antidepressant medication. These findings highlight the importance of clinicians screening for cognitive control dysfunction in patients with depression, particularly in later stages of adulthood.

Subthreshold depression may exist on a spectrum with major depressive disorder: Evidence from gray matter volume and morphological brain network

BACKGROUND

Subthreshold depression (StD) is a prevalent condition that may increase the risk of incident major depressive disorder (MDD). However, the relationship between StD and MDD remains unclear.

METHODS

A total of 153 adult subjects, including 53 drug-naive MDD, 50 StD and 50 healthy control (HC) subjects, underwent a T1-weighted magnetic resonance imaging scan, and the gray matter volume (GMV) alterations among the three groups were quantitatively analyzed using voxel-based morphometry (VBM). Then, to capture the whole-brain connectivity characteristics, we constructed morphological brain networks (MBN) based on the similarity among brain regions of individual VBM images and compared the network connection strengths among the three groups.

RESULTS

The StD and MDD subjects had similar patterns of GMV reductions in the orbitofrontal cortex and left temporal gyrus, although the magnitude of the reductions was smaller in StD subjects. Moreover, a total of 21 morphological connections were significantly different among the three groups. For the majority of the different connections (15/21), the connection strength of the StD group took an intermediate position between that of the MDD and HC groups.

LIMITATIONS

There is still a lack of a consistent definition of StD, and the age range of the subjects in this study was wide. Meanwhile the mechanisms and biological significance of the MBN remains to be clarified.

CONCLUSIONS

These results may support the hypothesis that depression is better expressed as a spectrum and that StD exists on a spectrum with MDD.

Association between subthreshold depression and self-care behaviors in people with type 2 diabetes: a systematic review of observational studies

BACKGROUND

Self-care behaviors in people living with type 2 diabetes are important to achieving optimal glycemic control. Major depression in type 2 diabetes is associated with decreased adherence to self-care behaviors. The association between subthreshold depression and self-care behaviors, however, has not previously been systematically reviewed. The objective of this review is to determine the association between subthreshold depression and self-care behaviors.

METHODS

A systematic search was performed in five electronic databases that included MEDLINE, EMBASE, PsycINFO, Emcare, and CINAHL. Any observational studies in adults with type 2 diabetes, investigating the association between subthreshold depression and any self-care behaviors, were included in the review. Qualitative studies, review articles, and gray literature were excluded. Two reviewers independently completed the title and abstract and full-text screening, appraised the study quality, and extracted the data. A third reviewer resolved any discrepancies between the reviewers if needed. Included articles were critically appraised using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist. Meta-analyses were not conducted because criteria for conducting such analyses were not met.

RESULTS

A total of 6408 articles were identified through the database searching. After the abstract and full-text review, two articles met the inclusion criteria. One of the included study was cross-sectional while the other was a longitudinal study. Both studies showed inconsistent findings in the association between subthreshold depression and self-care behaviors. Important risks of bias were identified in the included studies.

DISCUSSION

The evidence from the two included studies on a possible association between subthreshold depression and self-care behaviors in adults with type 2 diabetes was not consistent and potentially biased. Our review established a gap in knowledge and suggests that further high-quality studies are needed to examine the association between subthreshold depression and self-care behaviors in people with type 2 diabetes.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018116373.

Behavioral and neural correlates of memory suppression in subthreshold depression

Many studies have demonstrated that healthy individuals can intentionally control memory. However, little is known about the behavioral and neural mechanisms of memory control in those with subthreshold depression (SD), a highly prevalent condition associated with severe impairments and a significant social burden. In this study, we used functional magnetic resonance imaging (fMRI) and a generalized form of task-dependent psychophysiological interaction (gPPI) analysis during the think/no-think task to examine the brain mechanism of memory suppression in SD participants. The behavioral results revealed that SD participants were unable to suppress negative memories. Neuroimaging data revealed that the SD group showed greater activation than the healthy control (HC) group in the prefrontal gyrus during memory processing. Moreover, gPPI analysis showed that the SD group had significantly lower right hippocampal functional coupling with the dorsolateral prefrontal cortex during negative memory suppression than the HC group. These results indicated that SD participants recruited more frontal control resources for memory suppression because of executive and prefrontal inhibitory dysfunction. However, the abnormal prefrontal-hippocampal inhibitory pathway resulted in a failure of the memory control process when the stimuli were negative. These findings provide some evidence for understanding why SD individuals have inefficient memory control of negative memories.

Usefulness of the 15-item geriatric depression scale (GDS-15) for classifying minor and major depressive disorders among community-dwelling elders

BACKGROUND

The 15-item geriatric depression scale (GDS-15) is a short form of GDS and is used to screen, diagnose, and evaluate depression in elderly individuals. Most previous studies evaluated the ability of GDS-15 to discriminate between depressive and non-depressive states. In this study, we investigated the multi-stage discriminating ability of GDS-15.

METHODS

A total of 774 participants, over 65 years of age were included (normal, n = 650; minor depressive disorder [MnDD], n = 94; major depressive disorder [MDD], n = 30). Multi-category receiver operating characteristic (ROC) surfaces were evaluated to identify three stages of geriatric depression. The optimal cutoff points were selected based on the volume under the ROC surface (VUS) and the Youden index.

RESULTS

In the results of multi-category classification analyses, VUS of the GDS-15 of 0.61 was obtained, and optimal cutoff points of the GDS-15 for multiple stages of depression of 4 (between normal and MnDD) and 11 (between MnDD and MDD) were derived. The Youden index for the GDS-15 was 0.49, and the derived optimal cutoff points were 5 and 10, for the multiple stages, respectively. The overall diagnostic accuracy based on the Youden index was superior to that based on the VUS in the GDS-15.

LIMITATIONS

The participants' cognitive function has potential to affect the GDS-15 score; nevertheless, the study included those with mild cognitive impairment.

CONCLUSIONS

GDS-15 was a useful tool to classify stages of geriatric depression into either minor or major depressive disorder.

Morbidity and mortality in very old individuals with subsyndromal depression: an 8-year prospective study

OBJECTIVES

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.

DESIGN AND SETTING

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

MEASUREMENTS

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.

RESULTS

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.

CONCLUSIONS

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.

Association between subthreshold depression and self-care behaviour in people with type 2 diabetes: a protocol for systematic review of observational studies

BACKGROUND

Depression is a common comorbidity in type 2 diabetes. Studies have consistently shown that major depression is associated with decreased diabetic self-care behaviour. People with subthreshold depression experience greater functional impairment, have a poorer quality of life and use health services more than those without depressive symptoms. Although subthreshold depression impacts self-care behaviour, the relationship between subthreshold depression and diabetes self-care behaviour has not been systematically reviewed. The objective of this systematic review is to determine the association between subthreshold depression and self-care behaviour in adults with type 2 diabetes.

METHODS

This protocol will follow the guideline of the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols 2015 (PRISMA-P-2015). A systematic search of literature will be conducted for observational studies reporting the association between subthreshold depression and self-care behaviour in adults aged 18 years or over and diagnosed with type 2 diabetes. Electronic databases including MEDLINE, EMBASE, PsycINFO, Emcare and CINAHL will be searched using predefined search terms. Title and abstract, full-text screening and data extraction of identified articles will be done by two reviewers independently. Discrepancies will be resolved by a third author. The methodological quality of the included studies will be assessed using The Joanna Briggs Institute (JBI) risk of bias tools. The review results will be presented in the form of narrative synthesis, and if sufficient studies are available and variability among the studies is low, a random effects meta-analysis will be done to quantify the result.

DISCUSSION

This review will synthesise evidence on the association between subthreshold depression and self-care behaviour in type 2 diabetic adults. The findings will be useful to researchers and policymakers to determine the most effective approach to overall diabetes management. The review will also identify research gaps in the current literature and provide direction for future research in this area of study.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018116373.

Course of subthreshold depression into a depressive disorder and its risk factors

BACKGROUND

Information on the natural course of subthreshold depression and risk factors for the development of a full-blown depressive disorder in the general population is scarce. This information is crucial to understand the development of depression and to advance indicated depression prevention.

METHODS

Using longitudinal data from a representative population-based study (the Netherlands Mental Health Survey and Incidence Study-2) we assessed 3-year course of subthreshold depression (depressive symptoms causing clinically significant distress for at least 2 weeks, or for 3 days per month for a year; n = 120), compared to an asymptomatic group (n = 4111) and a depressive disorder group (major depression or dysthymia; n = 294). Next, risk factors for the development of a depressive disorder among adults with subthreshold depression were determined.

RESULTS

Twelve percent of the subthreshold cases developed a full-blown depressive disorder during 3-year follow-up. Risk factors were lower social support, having recurrent short episodes of depressive symptomatology, remitted and current anxiety disorder, remitted substance use disorder, lifetime suicide thoughts, a chronic physical disorder and diminished mental and physical functioning.

LIMITATIONS

The number of subjects with subthreshold depression that developed a depressive disorder was small. This limits the possibility to detect significant risk factors.

CONCLUSION

Only a minority of the subthreshold cases developed a full-blown depressive disorder over three years. This shows that subthreshold depression does not, by itself, carry an a priori risk to warrant focusing indicated prevention. The identified risk factors could help to detect those subthreshold cases in whom depression prevention is economically and practically viable.

Subthreshold depression among diabetes patients in Beijing: Cross-sectional associations among sociodemographic, clinical, and behavior factors

BACKGROUND

This study explores the prevalence of subthreshold depression (SubD) and its association with factors in type 2 diabetes mellitus (T2DM) patients.

METHODS

This cross-sectional study involved 808 outpatients with T2DM from ten hospitals in Beijing between September 2015 and January 2016. All participants completed the Patient Health Questionnaire 9-item (PHQ-9) to evaluate depressive status, with scores between 5 and 14 considered SubD. Conditional logistic regression was conducted to investigate the variables associated with SubD in T2DM patients.

RESULTS

T2DM patients with SubD comprised 11.6% (n = 94) of the sample. The odd ratios for the variables having significant positive associations with SubD were: being a women (OR = 1.90; 95%CI: 1.09-3.32), divorced/widowed (OR = 3.27; 95%CI: 1.46-7.30), comorbidity of cerebrovascular disease (OR = 2.00; 95%CI: 1.06-3.76), more diabetic complications (OR = 8.04; 95%CI: 2.77-23.31), and higher HbA1c in men (OR = 2.41; 95%CI: 1.25-4.64). Being older (OR = 0.78; 95%CI: 0.62-0.98), exercising more (OR = 0.44; 95%CI: 0.22-0.91) and poverty (OR = 0.36; 95%CI: 0.19-0.69) were negatively related to SubD.

LIMITATIONS

The sample was mainly recruited from hospital settings, which limits generalization. The study's cross-sectional design precludes making causal inferences.

CONCLUSIONS

The proportion of SubD was estimated to be 11.6% among T2DM patients in Beijing. Having more diabetic complications and being divorced/widowed made the odds of having SubD 8-fold and 3-fold higher than not having it, respectively. The relationship between SubD and diabetes necessitates early screening for milder forms of depression, which can alleviate the social burden and individual impairment from major depression or other chronic diseases.

Direct Costs of Very Old Persons with Subsyndromal Depression: A 5-Year Prospective Study

OBJECTIVES

This study aimed to compare, over a 5-year period, the prospective direct healthcare costs and service utilization of persons with subsyndromal depression (SSD) and non-depressive persons (ND), in a population of very old persons. A second aim was to develop a model that predicts direct healthcare costs in very old persons with SSD.

DESIGN AND SETTING

A prospective population-based study was undertaken on 85-year-old persons in Sweden.

MEASUREMENTS

Depressiveness was screened with the Geriatric Depression Scale at baseline and at 1-year follow-up, and the results were classified into ND, SSD, and syndromal depression. Data on individual healthcare costs and service use from a 5-year period were derived from national database registers. Direct costs were compared between categories using Mann-Whitney U tests, and a prediction model was identified with linear regression.

RESULTS

For persons with SSD, the direct healthcare costs per month of survival exceeded those of persons with ND by a ratio 1.45 (€634 versus €436), a difference that was significant even after controlling for somatic multimorbidity. The final regression model consisted of five independent variables predicting direct healthcare costs: male sex, activities of daily living functions, loneliness, presence of SSD, and somatic multimorbidity.

CONCLUSIONS

SSD among very old persons is associated with increased direct healthcare costs independently of somatic multimorbidity. The associations between SSD, somatic multimorbidity, and healthcare costs in the very old need to be analyzed further in order to better guide allocation of resources in health policy.

High Beck Depression Inventory 21 scores in adolescents without depression are associated with negative self-image and immature defense style

Beck Depression Inventory (BDI) is widely used in assessing adolescents' psychological wellbeing, but occasionally the result diverges from diagnostics. Our aim was to identify factors associated with discrepancies between BDI scores and diagnostic assessment in adolescent psychiatric patients and general population. The study comprised 206 inpatients (13-17 years old) and 203 age and gender matched non-referred adolescents. Study subjects filled self-reports on depression symptoms (BDI-21), alcohol use (AUDIT), defense styles (DSQ-40) and self-image (OSIQ-R), and on background information and adverse life events. Diagnostics was based on K-SADS-PL interview, and/or clinical interview and clinical records when available. We compared subjects who scored in BDI-21 either 0-15 points or 16-63 points firstly among subjects without current unipolar depression (n = 284), secondly among those with unipolar depression (n = 105). High BDI-21 scores in subjects without depression diagnosis (n = 48) were associated with female sex, adverse life events, parents' psychiatric problems, higher comorbidity, higher AUDIT scores, worse self-image and more immature defense styles. Low BDI-21 scores among subjects with depression diagnosis (n = 23) were associated with male sex, more positive self-image and less immature defense style. In conclusion, high BDI-21 scores in the absence of depression may reflect a broad range of challenges in an adolescent's psychological development.

Depression is associated with the long-term outcome of lumbar spinal stenosis surgery: a 10-year follow-up study

BACKGROUND CONTEXT

Depression is associated with greater postoperative disability in patients with lumbar spinal stenosis (LSS). No previous studies have reported the association in a 10-year follow-up.

PURPOSE

To evaluate the association between preoperative and postoperative depressive symptoms and the surgical outcome among patients with LSS in a 10-year follow-up. In addition, we examined the effects of the depressive burden on the surgical outcome.

DESIGN

A prospective observational follow-up study.

PATIENT SAMPLE

A total of 102 patients with LSS underwent decompressive surgery, and 72 of the original sample participated in the 10-year follow-up study.

OUTCOME MEASURES

Self-report measures: the Oswestry Disability Index (ODI) and visual analog scale (VAS).

METHODS

Data were collected using a questionnaire that was administered seven times during the study period. Depressive symptoms were measured with the Beck Depressive Inventory (BDI). The depressive burden was calculated by summing the preoperative and all follow-up BDI scores. Statistical analysis included cross-sectional group comparisons and linear mixed models. The authors report no conflicts of interest related to this work.

RESULTS

The high depressive burden group had a poorer outcome for pain, disability, and the walking distance at the 10-year follow-up. In linear mixed models, a higher preoperative BDI score associated with higher disability. Furthermore, higher postoperative BDI scores and the depressive burden were associated with higher disability and pain in the 10-year follow-up.

CONCLUSIONS

Patients with LSS with even slightly elevated depressive symptoms have an increased risk of postoperative pain and disability in a 10-year follow-up. To improve the surgical outcome among these patients, screening for depression both preoperatively and during the rehabilitation following surgery is important.

Effects of behavioral activation on default mode network connectivity in subthreshold depression: A preliminary resting-state fMRI study

BACKGROUND

Subthreshold depression is a risk factor for major depressive disorder, and it is known to have a negative impact on quality of life (QOL). Although behavioral activation, which is one type of cognitive behavioral therapy, is an effective psychological intervention for subthreshold depression, neural mechanisms of behavioral activation are unclear. Enhanced functional connectivity between default mode network (DMN) and the other regions has been demonstrated in participants with subthreshold depression. The purpose of this study was to examine the effects of behavioral activation on DMN abnormalities by using resting-state functional MRI (rs-fMRI).

METHODS

Participants with subthreshold depression (N =40) were randomly assigned to either an intervention group or a non-intervention group. They were scanned using rs-fMRI before and after the intervention. Independent component analysis indicated three subnetworks of the DMN.

RESULTS

Analyzing intervention effects on functional connectivity of each subnetwork indicated that connectivity of the anterior DMN subnetwork with the dorsal anterior cingulate was reduced after the intervention. Moreover, this reduction was correlated with an increase in health-related QOL.

LIMITATIONS

We did not compare the findings with healthy participants. Further research should be conducted by including healthy controls to verify the results of this study.

CONCLUSIONS

Mechanisms of behavioral activation might be related to enhanced ability to independently use the dACC and the DMN, which increases an attention control to positive external stimuli. This is the first study to investigate neural mechanisms of behavioral activation using rs-fMRI.

Depressive states among adults with diabetes: Findings from the National Health and Nutrition Examination Survey, 2007-2012

AIMS

To determine (1) the prevalence of SubD states among adults with diabetes, and (2) whether evidence exists of an independent association between diabetes status and SubD, controlling for selected confounders.

METHODS

Data from the 2007-2012 National Health and Nutrition Examination Surveys were combined to estimates of depressive states by diabetes status among the noninstitutionalized U.S. adult population, and to assess the association of diabetes status and depressive states using a polytomous logistic regression model.

RESULTS

An estimated 17%, or 3.7 million, of U.S. adults with diabetes (diagnosed and undiagnosed) met criteria for either mD or ssD. The majority of SubD cases with diabetes were found to be ssD (10.1%) compared with mD (6.9%). After controlling for the effects of age, sex, race and ethnicity, education, body mass index, and poverty as covariates, an independent association persists between diagnosed diabetes and each SubD grouping (ssD: OR=1.82, CIs 1.33, 2.47; mD: OR=1.95, CIs 1.39, 2.74) compared with respondents having no diabetes. No association was found between depression and undiagnosed diabetes or prediabetes compared with those having no diabetes.

CONCLUSION

Milder forms of depression such as ssD and mD are more extant than major depressive episodes among adults with diabetes. The odds that an adult with diagnosed diabetes meets the criteria for ssD or mD are higher by 80% and 95%, respectively, after controlling for age, sex, race and ethnicity, education, body mass index, and poverty factors when compared against adults with no diabetes.

Prevalence and correlates of DSM-5 major depressive and related disorders in the community

Although the DSM-5 has suggested the two new categories of Persistent Depressive Disorders (PDD) and Other Specified Depressive Disorders (OSDD), no study so far has applied the DSM-5 criteria throughout the range of depressive disorders. The aims of the present study were to 1) establish the lifetime prevalence of specific depressive disorders according to the new DSM-5 definitions in a community sample, and 2) determine their clinical relevance in terms of socio-demographic characteristics, comorbidity, course and treatment patterns. The semi-structured Diagnostic Interview for Genetic Studies was administered by masters-level psychologists to a random sample of an urban area (n=3720). The lifetime prevalence was 15.2% for PDD with persistent major depressive episode (MDE), 3.3% for PDD with pure dysthymia, 28.2% for Major Depressive Disorder (MDD) and 9.1% for OSDD. Subjects with PDD with persistent MDE were the most severely affected, followed by those with recurrent MDD, single episode MDD, PDD with pure dysthymia and OSDD and finally those without depressive disorders. Our data provide further evidence for the clinical significance of mild depressive disorders (OSDD), but cast doubt on the pertinence of lumping together PDD with persistent MDE and the former DSM-IV dysthymic disorder within the new PDD category.

Severity of complicated versus uncomplicated subthreshold depression: New evidence on the "Monotonicity Thesis" from the national comorbidity survey

BACKGROUND

"Complicated" subthreshold depression (CsD) includes at least one of six pathosuggestive "complicated" symptoms: >6 months duration, marked role impairment, sense of worthlessness, suicidal ideation, psychotic ideation, and psychomotor retardation. "Uncomplicated" subthreshold depression (UsD) has no complicated features. Whereas studies show that complicated (CMDD) versus uncomplicated (UMDD) major depression differ substantially in severity and prognosis, UsD and CsD severity has not been previously compared. This study evaluates UsD and CsD pathology validator levels and examines whether the complicated/uncomplicated distinction offers incremental concurrent validity over the standard number-of-symptoms dimension as a depression severity measure.

METHODS

Using nationally representative community data from the National Comorbidity Survey, seven depression lifetime history subgroups were identified: one MDD screener symptom (n=1432); UsD (n=430); CsD (n=611); UMDD (n=182); and CMDD with 5-6 symptoms (n=518), 7 symptoms (n=217), and 8-9 symptoms (n=291). Severity was evaluated using five concurrent pathology validators: suicide attempt, interference with life, help seeking, hospitalization, and generalized anxiety disorder.

RESULTS

CsD validator levels are substantially higher than both UsD and UMDD levels, and similar to mild CMDD, disconfirming the "monotonicity thesis" that severity increase with symptom number. Complicated/uncomplicated status predicts severity, and when complicatedness is controlled, number of symptoms no longer predicts validator levels.

LIMITATIONS

Diagnoses were based on respondents' fallible retrospective symptom reports during a lay-administered structured interview, which may not yield diagnoses comparable to clinicians' assessments.

CONCLUSION

CsD is more severe than UsD and comparable to mild MDD. Complicated status more validly indicates depression severity than the standard number-of-symptoms measure.

Anatomical brain difference of subthreshold depression in young and middle-aged individuals

BACKGROUND

Subthreshold depression (StD) is associated with substantial functional impairments due to depressive symptoms that do not fully meet the diagnosis of major depressive disorder (MDD). Its high incidence in the general population and debilitating symptoms has recently put it at the forefront of mood disorder research.

AIM

In this study we investigated common volumetric brain changes in both young and middle-aged StD patients.

METHODS

Two cohorts of StD patients, young and middle-aged, (n = 57) and matched controls (n = 76) underwent voxel-based morphometry (VBM).

RESULTS

VBM analysis found that: 1) compared with healthy controls, StD patients showed decreased gray matter volume (GMV) in the bilateral globus pallidus and precentral gyrus, as well as increased GMV in the left thalamus and right rostral anterior cingulate cortex/medial prefrontal cortex; 2) there is a significant association between Center for Epidemiological Studies Depression Scale scores and the bilateral globus pallidus (negative) and left thalamus (positive); 3) there is no interaction between age (young vs. middle-age) and group (StD vs. controls).

CONCLUSIONS

Our findings indicate significant VBM brain changes in both young and middle-aged individuals with StD. Individuals with StD, regardless of age, may share common neural characteristics.

Process evaluation of a stepped-care program to prevent depression in primary care: patients' and practice nurses' experiences

Background

Depression is common in patients with diabetes type 2 (DM2) and/or coronary heart disease (CHD), with high personal and societal burden and may even be preventable. Recently, a cluster randomized trial of stepped care to prevent depression among patients with DM2 and/or CHD and subthreshold depression in Dutch primary care (Step-Dep) versus usual care showed no effectiveness. This paper presents its process evaluation, exploring in-depth experiences from a patient and practice nurse perspective to further understand the results.

Methods

A qualitative study was conducted. Using a purposive sampling strategy, data were collected through semi-structured interviews with 24 participants (15 patients and nine practice nurses). All interviews were audiotaped and transcribed verbatim. Atlas.ti 5.7.1 software was used for coding and structuring of themes. A thematic analysis of the data was performed.

Results

The process evaluation showed, even through a negative trial, that Step-Dep was perceived as valuable by both patients and practice nurses; perceived effectiveness on improving depressive symptoms varied greatly, but most felt that it had been beneficial for patients’ well-being. Facilitators were: increased awareness of mental health problems in chronic disease management and improved accessibility and decreased experienced stigma of receiving mental health care. The Patient Health Questionnaire 9 (PHQ-9), used to determine depression severity, functioned as a useful starting point for the conversation on mental health and patients gained more insight into their mental health by regularly filling out the PHQ-9. However, patients and practice nurses did not widely support its use for monitoring depressive symptoms or making treatment decisions. Monitoring mental health was deemed important in chronically ill patients by both patients and practice nurses and was suggested to start at the time of diagnosis of a chronic disease. Appointed barriers were that patients were primarily motivated to participate in scientific research rather than their intrinsic need to improve depressive symptoms. Additionally, various practice nurses preferred offering individually based therapy over pre-determined interventions in a protocolled sequence and somatic practice nurses expressed a lack of competence to recognise and treat mental health problems.

Conclusion

This study demonstrates both the benefits and unique demands of programs such as Step-Dep. The appointed facilitators and barriers could guide the development of future studies aiming to prevent depression in similar patient groups.

Symptom quality versus quantity in judging prognosis: Using NESARC predictive validators to locate uncomplicated major depression on the number-of-symptoms severity continuum

BACKGROUND

Uncomplicated major depressive disorder (UMDD) is defined as MDD that does not include any of six pathosuggestive features: more than six months duration, marked functional impairment, sense of worthlessness, suicidal ideation, psychotic ideation, and psychomotor retardation. Complicated MDD (CMDD) includes all episodes containing one or more of these features. UMDD has been shown to be lower than CMDD and indistinguishable from no-MDD-history on predictive pathology validators. This study's purpose is to establish where on the number-of-symptoms depressive continuum UMDD is located, using the criterion of predictive validity.

METHODS

Using two-wave longitudinal community data, seven baseline depression history subgroups were identified: no MDD symptoms (n=23,214), one MDD screener symptom (n=609), subthreshold or "minor" depression (mD; 2-4 MDD symptoms; n=2,623), UMDD (n=505), and complicated MDD with 5-6 symptoms (n=1,106), 7 symptoms (n=1,200), and 8-9 symptoms (n=2,408). Predictive validity was evaluated by four follow-up variables: major depressive episode; generalized anxiety disorder; suicide attempt; and manic/hypomanic episode.

RESULTS

UMDD predictive pathology validator rates are not significantly different from rates for subthreshold mD but significantly different from those for all other depression categories; UMDD is higher in symptoms but lower in validator levels than 5-6 symptom CMDD.

LIMITATIONS

Baseline and follow-up diagnoses were based on respondents' fallible retrospective symptom reports in response to a lay-administered structured questionnaire, which may not yield diagnoses comparable to clinicians' assessments.

CONCLUSION

Uncomplicated MDD's follow-up outcomes resemble subthreshold depression, not CMDD, even when CMDD has less symptoms. Clinical decisions should reflect the relatively benign prognosis of uncomplicated MDD.

The relevance of 'mixed anxiety and depression' as a diagnostic category in clinical practice

According to ICD-10 criteria, mixed anxiety and depressive disorder (MADD) is characterized by co-occurring, subsyndromal symptoms of anxiety and depression, severe enough to justify a psychiatric diagnosis, but neither of which are clearly predominant. MADD appears to be very common, particularly in primary care, although prevalence estimates vary, often depending on the diagnostic criteria applied. It has been associated with similarly pronounced distress, impairment of daily living skills, and reduced health-related quality of life as fully syndromal depression and anxiety. Although about half of the patients affected remit within a year, non-remitting patients are at a high risk of transition to a fully syndromal psychiatric disorder. The validity and clinical usefulness of MADD as a diagnostic category are under debate. It has not been included in the recently released DSM-5 since the proposed diagnostic criteria turned out to be not sufficiently reliable. Moreover, reviewers have disputed the justification of MADD based on divergent results regarding its prevalence and course, diagnostic stability over time, and nosological inconsistencies between subthreshold and threshold presentations of anxiety and depressive disorders. We review the evidence in favor and against MADD and argue that it should be included into classification systems as a diagnostic category because it may enable patients to gain access to appropriate treatment early. This may help to reduce patients' distress, prevent exacerbation to a more serious psychiatric disorder, and ultimately reduce the societal costs of this very common condition.