Investigating the association between body fat and depression via Mendelian randomization

Association of whole-body and regional body fat mass indexes with depressive symptoms and suicidal behaviors in Korean adults: The moderating role of age

BACKGROUND

The coexistence of obesity and mental health problems has been widely reported; however, the moderating role of age in these associations has been scarcely examined. We explored age-specific variations in the association of fat mass indexes (FMIs) with depressive symptoms and suicidal behaviors.

METHODS

This study included a nationwide sample of 4185 Korean adults. Whole-body and regional body fat mass were measured using bioelectrical impedance analysis. Depressive symptoms were determined based on the Patient Health Questionnaire-9, and suicidal ideation and planning over the past year were evaluated. Logistic regression was employed to assess the relationship between FMIs and mental health outcomes, and stratified analyses were conducted to assess age-specific variations in these associations.

RESULTS

In the younger age group (<45 years), a 1-standard deviation increase in the whole-body FMI was associated with 1.38 (95 % CI: 1.18-1.61) and 1.48 (95 % CI: 1.50-2.08) times higher odds of depressive symptoms and suicidal planning, respectively. Similar positive associations between FMIs and depressive symptoms and suicidal planning were observed for regional FMIs, including trunk, arm, and leg fat mass. However, no clear associations were observed among individuals aged ≥45 years between whole-body or regional FMIs and mental health problems.

LIMITATIONS

The cross-sectional design hinders causal interpretation.

CONCLUSION

This study observed significant age-specific variations in the relationship between FMIs and depressive symptoms and suicidal behaviors.

Development of a nomogram for predicting depression risk in patients with chronic kidney disease: an analysis of data from the US National Health and Nutrition Examination Survey, 2007-2014

OBJECTIVES

Depression frequently occurs among individuals suffering from chronic kidney disease (CKD), diminishing life quality considerably while accelerating the disease course. This study aims to create a predictive model to identify patients with CKD at high risk for depression.

DESIGN

Analysis of cross-sectional data.

SETTING

US National Health and Nutrition Examination Survey (2007-2014).

PARTICIPANTS

A total of 2303 patients with CKD (weighted=17 422 083) with complete data were included in the analysis.

OUTCOME MEASURES

We used the least absolute shrinkage and selection operator regression for variable selection and constructed a weighted logistic regression model through stepwise backward elimination based on minimisation of the Akaike information criterion, visualised with a nomogram. Internal validation was conducted using 1000 bootstrap resamples. Model discrimination was assessed using receiver operating characteristic curves, calibration was evaluated using the Hosmer-Lemeshow test and calibration curves, and net benefits and clinical impact were analysed using decision curve analysis and comparative impact chart curves.

RESULTS

The final model included 10 predictors: age, gender, poverty income ratio, body mass index, smoking, sleep time, sleep disorder, chest pain, diabetes and arthritis. The model achieved an area under the curve of 0.776 (95% CI 0.745 to 0.806) with good fit (Hosmer-Lemeshow p=0.805). Interventions within the 0.1-0.6 probability range showed significant benefits.

CONCLUSION

We have crafted a predictive model with good discriminative power that could potentially help clinicians identify patients with CKD at high risk for depression, thereby facilitating early intervention and improving the prognosis of these patients.

Association between body fat percentage and depression: A cross-sectional study of NHANES

BACKGROUND

Obesity and depression often co-occur and are interdependent. However, evidence regarding the association between body fat percentage in different regions and depression is scarce. Additionally, the impacts of sex-specific and BMI-stratified differences on the relationship between body fat percentage and depression remain unclear.

METHODS

Data were drawn from the NHANES for the years 2005-2006 and 2011-2018. Body fat percentage was assessed using dual-energy X-ray absorptiometry (DXA). Depression was evaluated using the Patient Health Questionnaire-9 (PHQ-9). Survey-weighted binary logistic regression analyses were employed to investigate the relationship between body fat percentage and depression. Stratification analysis were stratified by sex and BMI.

RESULTS

This study comprised 10,694 participants. Controlling confounders, the higher quartile of total body fat percentage was associated with increased OR for depression (Q4 vs Q1: OR, 1.46; 95 % CI, 1.04-2.05) as well as for leg (Q4 vs Q1: OR, 1.48; 95 % CI, 1.07-2.05), gynoid (Q4 vs Q1: OR, 1.51; 95 % CI, 1.11-2.05), subtotal (Q4 vs Q1: OR, 1.47; 95 % CI, 1.06-2.03) and head (Q3 vs Q1: OR, 1.30; 95 % CI, 1.00-1.68). In stratification analysis by sex and BMI, body fat percentage seemed to be more closely associated with depression in males or in the underweight and overweight groups.

LIMITATION

Cross-sectional study design and self-reported depression.

CONCLUSIONS

Elevated body fat percentage was strongly associated with higher prevalence of depression, especially in males or in the underweight and overweight groups.

Obesity and Cardiometabolic Disease: Insights From Genetic Studies

Obesity is a highly prevalent chronic disease and major driver of both atherosclerotic heart disease and heart failure. Obesity is also a heritable neuronal disease with heritability estimates of up to 70%. In this work I review how common genetic variants, usually with small effect sizes, contribute to the risk for developing obesity and cardiometabolic disease in the majority of people and how this can be further modulated by environmental factors. In some individuals, rare genetic variants with large effect sizes can influence the risk of developing obesity, in some cases in a Mendelian manner. I also address how identification of these rare variants has led to fundamental biologic insights into how satiety and reward are biologic processes, has led to more personalized treatments, and has identified potential novel drug treatments. Biologic insights derived from genetic studies of obesity have also improved our understanding of the causal mediators between obesity and cardiovascular disease. A major limitation of studies to date is that they involved mostly people of European ancestry. Studying more diverse populations will improve our understanding of obesity and cardiometabolic disease. Lessons derived from genetic studies make a compelling case for increasing accessibility to therapies that have sustained efficacy in managing obesity and improving health. This increased knowledge must also inform public health initiatives that will reduce the prevalence of obesity in the coming decades.

Somatization and Body Composition: Findings from a Cross-Sectional Study on Non-Clinical Young Adults

BACKGROUND/OBJECTIVES

Lifestyle is a significant, common, and easily modifiable factor capable of increasing or reducing the risk of acquiring many diseases. Currently, there is a research gap as too little scientific attention has been focused on exploring the relationship between mental health and nutritional status in various populations. Moreover, the association between body composition and somatization has not been fully disclosed. Therefore, this study aimed to assess the associations of body composition with the symptomatology of somatization in an environmentally vulnerable sample of young adults.

METHODS

A single cross-sectional study included young non-clinical Lithuanian students (n = 1223) aged 21.7 ± 3.9. The body adiposity status of the study participants was estimated using both the body mass index (BMI) and the Body Adiposity Estimator (CUN-BAE) method. Fat-free mass was evaluated via the adjusted fat-free mass index equation (FFMIadj). The Patient Health Questionnaire (PHQ-15) was applied to assess the severity of the perceived symptoms of a somatic symptom disorder (SSD).

RESULTS

The CUN-BAE was considered to be a better predictor of adiposity than the BMI because 14.7% of females and 6.2% of males were interpreted as obese using the CUN-BAE, while the BMI equation identified participants as having a normal body weight. The highest rates of somatization were found in 18.6% of the cohort. Young adults with higher amounts of body fat mass (β: 0.050, 95% confidence interval (95% CI): 0.013; 0.084, p = 0.007) and lower FFMI are prone to a higher risk for developing somatization (β: -0.429, 95% CI: -0.597; -0.260, p < 0.001).

CONCLUSIONS

Our study revealed that body composition is significantly related to multiple somatic complaints throughout a range of measurements. However, in contrast to the CUN-BAE tool, the BMI equation underestimated the relationship between body fat and mental health outcomes in young adults. Even though nutritional status along with targeted physical load, as the mediators, are likely to play a significant role in the maintenance of optimal body composition and mental health outcomes, healthcare providers are recommended to advise individuals to lower their body fat percentage and increase fat-free mass in order to reduce the risk of somatization.

Investigating the causal effects of childhood and adulthood adiposity on later life mental health outcome: a Mendelian randomization study

BACKGROUND

Obesity particularly during childhood is considered a global public health crisis and has been linked with later life health consequences including mental health. However, there is lack of causal understanding if childhood body size has a direct effect on mental health or has an indirect effect after accounting for adulthood body size.

METHODS

Two-sample Mendelian randomization (MR) was performed to estimate the total effect and direct effect (accounting for adulthood body size) of childhood body size on anxiety and depression. We used summary statistics from a genome-wide association study (GWAS) of UK Biobank (n = 453,169) and large-scale consortia of anxiety (Million Veteran Program) and depression (Psychiatric Genomics Consortium) (n = 175,163 and n = 173,005, respectively).

RESULTS

Univariable MR did not indicate genetically predicted effects of childhood body size with later life anxiety (beta = - 0.05, 95% CI = - 0.13, 0.02) and depression (OR = 1.06, 95% CI = 0.94, 1.20). However, using multivariable MR, we observed that the higher body size in childhood reduced the risk of later life anxiety (beta = - 0.19, 95% CI = - 0.29, - 0.08) and depression (OR = 0.83, 95% CI = 0.71, 0.97) upon accounting for the effect of adulthood body size. Both univariable and multivariable MR indicated that higher body size in adulthood increased the risk of later life anxiety and depression.

CONCLUSIONS

Higher body size in adulthood may increase the risk of anxiety and depression, independent of childhood higher body size. In contrast, higher childhood body size does not appear to be a risk factor for later life anxiety and depression.

Anthropometric Measurements and Weight Management Nutrition Knowledge: A Cross-Sectional Study in Turkey

This study aimed to examine the relationships between academic programs, gender, anthropometric measurements, and the Weight Management Nutrition Knowledge Questionnaire (WMNKQ) score. Results indicated that 37.7% of male and 15.3% of female students were overweight, with significant gender differences in BMI, waist/height ratio, waist/hip ratio, and waist circumference (all p < .001, except waist circumference p = .024). WMNKQ scores also varied significantly by gender and BMI classification (p < .05). Students in health-related fields scored higher on nutrition knowledge than those in other faculties (p = .000). Findings emphasize the importance of weight management among university students, who may face lifestyle changes affecting healthy eating habits.

Association between different diet quality scores and depression risk: the REGICOR population-based cohort study

BACKGROUND

Our aim was to determine the association between diet quality and depression incidence in the population-based REGICOR cohort study, Catalonia, Spain.

METHODS

Prospective observational study using participants' baseline (2003-2006), follow-up (2007-2013) and clinical records data. Five diet quality scores were derived from a food frequency questionnaire (FFQ) at baseline: the relative Mediterranean Diet Score (rMED), the Modified Mediterranean Diet Score (ModMDS), a Dietary Approaches to Stop Hypertension (DASH) score, a Healthful Plant-based Diet Index (HPDI) and the World Health Organization Healthy Diet Indicator (WHO-HDI). Participants using pharmacological antidepressant treatment were excluded as a proxy for presence of depression at baseline. At follow-up, the Patient Health Questionnaire (PHQ-9) was applied to assess depressive symptoms (≥ 10 defining depressive disorder). A secondary outcome was depression diagnosis assessed through clinical records. Logistic regression and Cox proportional hazards models were used.

RESULTS

Main analysis included 3046 adults (50.3% women) with a mean age of 54.7 (SD = 11.6) years. After 6-years follow-up, 184 (6.04%) cases of depressive disorder were identified. There was 16% lower odds of depressive disorder per 1SD increase of rMED (OR = 0.84; 95%CI = 0.71-0.98). Secondary outcome analysis (n = 4789) identified 261 (5.45%) incident cases of clinical depression diagnosis over 12 years follow-up, and 19% lower risk of clinical depression was observed with the WHO-HDI (HR = 0.81; 95%CI = 0.70-0.93). Adjusting for BMI did not attenuate the findings.

CONCLUSIONS

A significant inverse association between diet quality and depression incidence was found in this population-based cohort study, independent of sociodemographic, health and lifestyle. Adherence to a healthy diet could be a complementary intervention for the prevention of depression.

Microbiota Alters and Its Correlation with Molecular Regulation Underlying Depression in PCOS Patients

Depression is one of the complications in patients with polycystic ovary syndrome (PCOS) that leads to considerable mental health. Accumulating evidence suggests that human gut microbiomes are associated with the progression of PCOS and depression. However, whether microbiota influences depression development in PCOS patients is still uncharacterized. In this study, we employed metagenomic sequencing and transcriptome sequencing (RNA-seq) to profile the composition of the fecal microbiota and gene expression of peripheral blood mononuclear cells in depressed women with PCOS (PCOS-DP, n = 27) in comparison to mentally healthy women with PCOS (PCOS, n = 18) and compared with healthy control (HC, n = 27) and patients with major depressive disorder (MDD, n = 29). Gut microbiota assessment revealed distinct patterns in the relative abundance in the PCOS-DP compared to HC, MDD, and PCOS groups. Several gut microbes exhibited uniquely and significantly higher abundance in the PCOS-DP compared to PCOS patients, inducing EC Ruminococcus torques, Coprococcus comes, Megasphaera elsdenii, Acidaminococcus intestini, and Barnesiella viscericola. Bacteroides eggerthii was a potential gut microbial biomarker for the PCOS-DP. RNA-seq profiling identified that 35 and 37 genes were significantly elevated and downregulated in the PCOS-DP, respectively. The enhanced differential expressed genes (DEGs) in the PCOS-DP were enriched in pathways involved in signal transduction and endocrine and metabolic diseases, whereas several lipid metabolism pathways were downregulated. Intriguingly, genes correlated with the gut microbiota were found to be significantly enriched in pathways of neurodegenerative diseases and the immune system, suggesting that changes in the microbiota may have a systemic impact on the expression of neurodegenerative diseases and immune genes. Gut microbe-related DEGs of CREB3L3 and CCDC173 were possible molecular biomarkers and therapeutic targets of women with PCOS-DP. Our multi-omics data indicate shifts in the gut microbiome and host gene regulation in PCOS patients with depression, which is of possible etiological and diagnostic importance.

Mendelian randomization analysis reveals causal association of anthropometric measures on sepsis risk and mortality

The objective of this study was to explore the potential causalities of fat mass, nonfat mass and height (henceforth, 'anthropometric measures') with sepsis risk and mortality. We conducted the Mendelian randomization (MR) investigation using genome-wide association study (GWAS) summary statistics of anthropometric measures, sepsis, and sepsis mortality. The GWAS summary data from the UK Biobank was used. Firstly, MR analysis was performed to estimate the causal effect of anthropometric measures on the risk of sepsis. The inverse-variance weighted (IVW) method was utilized as the primary analytical approach, together with weighted median-based method. Cochrane's Q test and MR-Egger intercept test were performed to assess heterogeneity and pleiotropy, respectively. Finally, we performed a series of sensitivity analyses to enhance the precision and veracity of our findings. The IVW method showed that genetically predicted weight-related measures were suggestively linked to an increased risk of sepsis. However, height displayed no causal association with sepsis risk and mortality. Furthermore, weight-related measures also displayed significant MR association with the sepsis mortality, except body nonfat mass and right leg nonfat mass. However, MVMR analysis indicated the observed effects for weight-related measures in the univariable MR analyses are more likely a bias caused by the interrelationship between anthropometric measures. According to the MR-Egger intercept assessment, our MR examination was not influenced by horizontal pleiotropy (all p>0.05). Moreover, the reliability of the estimated causal association was confirmed by the sensitivity analyses. In conclusion, these findings provided vital new knowledge on the role of anthropometric-related measures in the sepsis etiology.

Associations between Waist Circumference and Sex Steroid Hormones in US Adult Men: Cross-Sectional Findings from the NHANES 2013-2016

Background

Obesity is recognized as a major public health issue worldwide, characterized by a growing prevalence among adult males. Several studies have identified an association between obesity and sex steroid hormone levels but only a few have considered the relationship between waist circumference (WC) and sex hormone levels in adult males. This study therefore aimed to evaluate the relationships between waist circumference (WC) and various sex steroid hormone levels in adult males in the United States.

Methods

This study analyzed data from 3,359 adult males aged 20 years and above, who participated in the National Health and Nutrition Examination Survey (NHANES) from 2013-2016 in the United States. We collected demographic data, including WC, and serum levels of testosterone, estradiol, SHBG, FAI, and T/E2 ratio. We adjusted the variables using multiple linear regression models with R 4.2.2 and EmpowerStats.

Results

After adjusting for confounders, WC was found to be negatively associated with testosterone (β = -0.117, P < 0.001) but positively correlated with estradiol (β = 0.002, P=0.002), especially beyond a WC of 104.5 cm (β = 0.004, P < 0.001). Underweight individuals showed a contrasting positive correlation between WC and testosterone (β = 0.351, P=0.016). WC was inversely related to SHBG, particularly when WC was ≤99.1 cm (β = -0.036, P < 0.001). The FAI initially increased and then decreased with WC, peaking at 98.6 cm. The T/E2 ratio negatively correlated with WC (β = -0.074, P < 0.001). These relationships varied among subgroups but remained unaffected by age or physical activity time.

Conclusions

Waist circumference is inversely correlated with testosterone, SHBG, and T/E2 ratio but positively correlated with estradiol, except for a positive correlation with testosterone in underweight males. Waist circumference serves as a crucial anthropometric measurement indicator for predicting sex steroid hormone levels in adult males.

Childhood obesity and adolescent follow-up depressive symptoms: exploring a moderated mediation model of body esteem and gender

Obesity is a well-recognized risk factor for adolescent depressive symptoms, but mediating mechanisms of this association have scarcely been studied. This study is unique in examining an indirect pathway of this link via body esteem (BE) prospectively from childhood (8-12 years) to adolescence (13-18 years). In addition, potential gender moderation was examined. This study utilized data from a case-control study comparing 100 children with and without obesity matched on important confounders (age, gender, and socioeconomic status). Our findings provide support for the mediating role of BE in the link between childhood weight status and adolescent depressive symptoms at a 5-year follow-up. This mediation effect did not differ between boys and girls. The findings suggest the relevance of specifically targeting children's BE in preventive intervention programs among children with obesity to prevent future mental health problems.

Sugar-Sweetened Beverages and Adverse Human Health Outcomes: An Umbrella Review of Meta-Analyses of Observational Studies

Our aim was to conduct an umbrella review of evidence from meta-analyses of observational studies investigating the link between sugar-sweetened beverage consumption and human health outcomes. Using predefined evidence classification criteria, we evaluated evidence from 47 meta-analyses encompassing 22,055,269 individuals. Overall, 79% of these analyses indicated direct associations between greater sugar-sweetened beverage consumption and higher risks of adverse health outcomes. Convincing evidence (class I) supported direct associations between sugar-sweetened beverage consumption and risks of depression, cardiovascular disease, nephrolithiasis, type 2 diabetes mellitus, and higher uric acid concentrations. Highly suggestive evidence (class II) supported associations with risks of nonalcoholic fatty liver disease and dental caries. Out of the remaining 40 meta-analyses, 29 were graded as suggestive or weak in the strength of evidence (classes III and IV), and 11 showed no evidence (class V). These findings inform and provide support for population-based and public health strategies aimed at reducing sugary drink consumption for improved health.

Brain-derived neurotrophic factor and C-reactive protein (CRP) biomarkers in suicide attempter and non-attempter major depression disorder (MDD) patients

BACKGROUND

In the available literature, levels of BDNF and CRP have been reported to correlate with suicide in depressive patients but there are inconsistencies in the results. We aimed to evaluate and compare BDNF and CRP concentrations in MDD patients with(MDD + SA) and without suicide attempts (MDD-SA) and healthy controls.

METHODS

30 (MDD + SA) patients, 30 (MDD-SA) patients, and 26 healthy controls were enrolled in the study. Age, sex, and BMI of patients were recorded. Blood sample was obtained for measurement of BDNF and CRP. Smoking and drug history, family history of suicide, and history of self-harm were also documented. Data were analyzed with SPSS version 22 and R version 4.1.1.

RESULTS

86 patients in three groups were evaluated (mean age: 28.45 ± 9.27 years, 56.71% female). Baseline and demographic parameters except for self-harm (40%, 3.3%, and 0% for MDD + SA, MDD-SA, and healthy controls, respectively, p = 0.001) did not differ between groups. CRP level was not significantly different between groups. BDNF showed a significant difference between groups (17.35, 16.45, and 19.43 for three groups, respectively, p < 0.001). An increase in BDNF decreased the odds of both depression and suicide. Roc curve showed excellent power for BDNF in discriminating MDD groups With healthy group.Roc can notdicrimiate MDD + SA and MDD-SA.

CONCLUSION

In our study, the concentration of BDNF differed significantly between depressed patients with/without suicide attempts and healthy controls which shows the association of BDNF with depression development and not suicide attempts. We could not find any association between CRP level and suicide attempt but still larger cohorts are needed for a definite conclusion.

Familial confounding of internalising symptoms and obesity in adolescents and young adults; a co-twin analysis

BACKGROUND

Obesity and internalising disorders, including depression and anxiety, often co-occur. There is evidence that familial confounding contributes to the co-occurrence of internalising disorders and obesity in adults. However, its impact on this association among young people is unclear. Our study investigated the extent to which familial factors confound the association between internalising disorders and obesity in adolescents and young adults.

SUBJECTS/METHODS

We used a matched co-twin design to investigate the impact of confounding by familial factors on associations between internalising symptoms and obesity in a sample of 4018 twins aged 16 to 27 years.

RESULTS

High levels of internalising symptoms compared to low levels increased the odds of obesity for the whole cohort (adjusted odds ratio [AOR] = 3.1, 95% confidence interval [CI]: 1.5, 6.8), and in females (AOR = 4.1, 95% CI 1.5, 11.1), but not in males (AOR = 2.8 95% CI 0.8, 10.0). We found evidence that internalising symptoms were associated with an increased between-pair odds of obesity (AOR 6.2, 95% CI 1.7, 22.8), using the paired analysis but not using a within-pair association, which controls for familial confounding. Sex-stratified analyses indicated high internalising symptoms were associated with increased between-pair odds of obesity for females (AOR 12.9, 95% CI 2.2, 76.8), but this attenuated to the null using within-pair analysis. We found no evidence of between or within-pair associations for males and weak evidence that sex modified the association between internalising symptoms and obesity (likelihood ratio test p = 0.051).

CONCLUSIONS

Some familial factors shared by twins confound the association between internalising symptoms and obesity in adolescent and young adult females. Internalising symptoms and obesity were not associated for adolescent and young adult males. Therefore, prevention and treatment efforts should especially address familial shared determinants of obesity, particularly targeted at female adolescents and young adults with internalising symptoms and those with a family history of these disorders.

Prevalence of sarcopenia and depressive symptoms among older adults: a scoping review

Sarcopenia causes a loss of skeletal muscle mass and decreases muscle strength and function. Depressive symptoms are a common cause of distress among geriatrics, significantly affecting the quality of life of older adults. Recently, studies have shown that a correlation exists between sarcopenia and depression. To determine the prevalence of sarcopenia and depressive symptoms and identify the factors associated with sarcopenia, we systematically searched the SCOPUS, Science Direct, and PubMed databases for papers on sarcopenia and depressive symptoms published from 2012 to 2022. We reviewed the literature on sarcopenia, depressive symptom prevalence, the prevalence of subjects with both sarcopenia and depressive symptoms, and the factors associated with sarcopenia. Only cross-sectional studies were included. Nineteen articles met the inclusion criteria for review, with overall sarcopenia prevalence ranging from 3.9% to 41.7%. The prevalence of depressive symptoms was reported in seven studies, ranging from 8.09% to 40%. The most commonly used tools to diagnose sarcopenia and depressive symptoms were the European Working Group on Sarcopenia in Older People consensus and the Geriatric Depression Scale, respectively. Being aged, malnourished, obese, having comorbidities (hypertension and diabetes), having impaired cognitive function, and having polypharmacy were found to be the factors associated with sarcopenia. Sarcopenia and depressive symptoms have been found to cause adverse health outcomes among older people. Appropriate nutritional assessments and interventions should be taken to manage these two geriatric conditions. Further studies should be planned, considering multidomain intervention strategies to improve sarcopenia and older people's mental health.

Body composition, lifestyle, and depression: a prospective study in the UK biobank

BACKGROUND

Obesity has been related to depression and adhering healthy lifestyle was beneficial to lower the risk of depression; however, little is known about the relationship between body composition and fat distribution with depression risk and the influence of body composition and fat distribution on the association of lifestyle and depression. Therefore, we aimed to investigate whether body composition and fat distribution were associated with the adverse events of depression and the relationship between lifestyle and depression.

METHODS

We included 330,131 participants without depression at baseline in the UK Biobank (mean age, 56.9 years; 53.83% females). The assessment of depression was sourced from health outcomes across self-report, primary care, hospital inpatient data, and death data. Body composition was determined by bioelectrical impedance. Seven lifestyles (no current smoking, moderate alcohol consumption, regular physical activity, healthy diet, less sedentary behavior, healthy sleep pattern, and appropriate social connection) were used to generate a lifestyle score.

RESULTS

During a median of 11.7 years of follow-up, 7576 incident depression occurred. All the body composition measures were positively associated with depression risk, with the Hazard ratios (HR) for the uppermost tertile (T3) versus the lowest tertile (T1) ranging from 1.26 (95% CI: 1.15-1.39) for trunk fat-free mass (TFFM) to 1.78 (1.62-1.97) for leg fat percentage (LFP). In addition, we found significant interactions between fat mass-related indices, especially leg fat mass (LFM) (p = 1.65 × 10-9), and lifestyle score on the risk of depression, for which the beneficial associations of a healthy lifestyle with the risk of depression were more evident among participants with low body fat measurement.

CONCLUSIONS

High levels of body composition measures were associated with an increased depression risk. Adverse body composition measures may weaken the link between a healthy lifestyle and a reduced risk of depression.

Composite healthy lifestyle, socioeconomic deprivation, and mental well-being during the COVID-19 pandemic: a prospective analysis

The adverse psychological and social impacts of COVID-19 pandemic are well characterized, but the role of composite, modifiable lifestyle factors that may interact to mitigate these impacts is not. The effect of socioeconomic deprivation on these lifestyle risks also remains unclear. Based on a nationally representative, longitudinal cohort, we assessed the association between a combination of pre-pandemic lifestyle factors and mental health conditions during pandemic, and the contribution of deprivation to it. Composite lifestyle factors included BMI, smoking status, alcohol consumption, physical activity, sedentary time, sleep duration, and fruit and vegetable intake, with lifestyle scores and lifestyle categories calculated for each participant. Symptoms of depression and anxiety, and personal well-being were assessed by validated scales during the pandemic. Socioeconomic deprivation was characterized by both individual-level (income, wealth, and education) and group-level factors (Index of Multiple Deprivation). Of the 5049 eligible participants (mean [SD] age, 68.1 [10.9] years; 57.2% were female) included in the study, 41.6% followed a favorable lifestyle, 48.9% followed an intermediate lifestyle, and 9.5% followed an unfavorable lifestyle. Compared with favorable lifestyle category, participants in the intermediate and unfavorable lifestyle category were at increased risk of mental health conditions, with the hazard ratio (HR) for trend per increment change towards unfavorable category of 1.17 (95% CI 1.09-1.26) for depression, 1.23 (1.07-1.42) for anxiety, and 1.39 (1.20-1.61) for low well-being. A significant trend of lower risk for mental health conditions with increasing number of healthy lifestyle factors was observed (P < 0.001 for trend). There were no significant interactions between lifestyle factors and socioeconomic deprivation for any of the outcomes, with similar HRs for trend per one increment change in lifestyle category observed in each deprivation group. Compared with those in the least deprived group with favorable lifestyle, participants in the most deprived group adherent to unfavorable lifestyle had the highest risk of mental health outcomes. These results suggest that adherence to a broad combination of healthy lifestyle factors was associated with a significantly reduced risk of mental health conditions during the COVID-19 pandemic. Lifestyle factors, in conjunction with socioeconomic deprivation, independently contribute to the risk of mental health issues. Although further research is needed to assess causality, the current findings support public health strategies and individual-level interventions that provide enhanced support in areas of deprivation and target multiple lifestyle factors to reduce health inequalities and promote mental well-being during the ongoing COVID-19 pandemic.

Multi-ancestry genome-wide association study of major depression aids locus discovery, fine mapping, gene prioritization and causal inference

Most genome-wide association studies (GWAS) of major depression (MD) have been conducted in samples of European ancestry. Here we report a multi-ancestry GWAS of MD, adding data from 21 cohorts with 88,316 MD cases and 902,757 controls to previously reported data. This analysis used a range of measures to define MD and included samples of African (36% of effective sample size), East Asian (26%) and South Asian (6%) ancestry and Hispanic/Latin American participants (32%). The multi-ancestry GWAS identified 53 significantly associated novel loci. For loci from GWAS in European ancestry samples, fewer than expected were transferable to other ancestry groups. Fine mapping benefited from additional sample diversity. A transcriptome-wide association study identified 205 significantly associated novel genes. These findings suggest that, for MD, increasing ancestral and global diversity in genetic studies may be particularly important to ensure discovery of core genes and inform about transferability of findings.

Mendelian randomization studies of depression: evidence, opportunities, and challenges

BACKGROUND

Major depressive disorder (MDD) poses a significant social and economic burden worldwide. Identifying exposures, risk factors, and biological mechanisms that are causally connected to MDD can help build a scientific basis for disease prevention and development of novel therapeutic approaches.

METHODS

In this systematic review, we assessed the evidence for causal relationships between putative causal risk factors and MDD from Mendelian randomization (MR) studies, following PRISMA. We assessed methodological quality based on key elements of the MR design: use of a full instrumental variable analysis and validation of the three key MR assumptions.

RESULTS

We included methodological details and results from 52 articles. A causal link between lifestyle, metabolic, inflammatory biomarkers, particular pathological states and MDD is supported by MR investigations, although results for each category varied substantially.

CONCLUSIONS

While this review shows how MR can offer useful information for examining prospective treatment targets and better understanding the pathophysiology of MDD, some methodological flaws in the existing literature limit reliability of results and probably underlie their heterogeneity. We highlight perspectives and recommendations for future works on MR in psychiatry.

The Influence of Adiposity Levels on the Relation between Perfluoroalkyl Substances and High Depressive Symptom Scores in Czech Adults

The extensive use and bioaccumulation of Perfluoroalkyl Substances (PFAS) over time raise concerns about their impact on health, including mental issues such as depression. This study aims to evaluate the association between PFAS and depression. In addition, considering the importance of PFAS as an endocrine disruptor and in adipogenesis, the analyses will also be stratified by body fat status. A cross-sectional study with 479 subjects (56.4% women, 25-89 years) was conducted. Four PFAS were measured: perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluorooctane sulfonate (PFOS). The Poisson regression model was applied using robust error variances. The fully adjusted model included age, sex, educational level, income, smoking, physical activity, body fat percentage, and the questionnaire to assess depression. The prevalence of depression and high body fat was 7.9% and 41.1%, respectively. Only PFOA was significantly associated with depression in the entire sample (prevalence rate (PR): 1.91; confidence interval (CI95%): 1.01-3.65). However, in the group with normal adiposity, PFOA (3.20, CI95%: 1.46-7.01), PFNA (2.54, CI95%: 1.29-5.00), and PFDA (2.09, CI95%: 1.09-4.00) were also significant. Future research should investigate the role of obesity as well as the biological plausibility and possible mechanisms increasing the limited number of evidences between PFAS and depression.

Obesity and psychological distress

The relationship between high body weight and mental health has been studied for several decades. Improvements in the quality of epidemiological, mechanistic and psychological research have brought greater consistency to our understanding of the links. Large-scale population-based epidemiological research has established that high body weight is associated with poorer mental health, particularly depression and subclinical depressive symptoms. There is some evidence for bidirectional relationships, but the most convincing findings are that greater body weight leads to psychological distress rather than the reverse. Particular symptoms of depression and distress may be specifically related to greater body weight. The psychological stress induced by weight stigma and discrimination contributes to psychological distress, and may in turn handicap efforts at weight control. Heightened systemic inflammation and dysregulation of the hypothalamic-pituitary-adrenal axis are biological mechanisms that mediate in part the relationship of greater body weight with poorer mental health. Changing negative societal attitudes to high body weights would improve the wellbeing of people living with obesity, and promote more effective weight-inclusive attitudes and behaviours in society at large, particularly in healthcare settings. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.

Comorbidity between major depressive disorder and physical diseases: a comprehensive review of epidemiology, mechanisms and management

Populations with common physical diseases - such as cardiovascular diseases, cancer and neurodegenerative disorders - experience substantially higher rates of major depressive disorder (MDD) than the general population. On the other hand, people living with MDD have a greater risk for many physical diseases. This high level of comorbidity is associated with worse outcomes, reduced adherence to treatment, increased mortality, and greater health care utilization and costs. Comorbidity can also result in a range of clinical challenges, such as a more complicated therapeutic alliance, issues pertaining to adaptive health behaviors, drug-drug interactions and adverse events induced by medications used for physical and mental disorders. Potential explanations for the high prevalence of the above comorbidity involve shared genetic and biological pathways. These latter include inflammation, the gut microbiome, mitochondrial function and energy metabolism, hypothalamic-pituitary-adrenal axis dysregulation, and brain structure and function. Furthermore, MDD and physical diseases have in common several antecedents related to social factors (e.g., socioeconomic status), lifestyle variables (e.g., physical activity, diet, sleep), and stressful live events (e.g., childhood trauma). Pharmacotherapies and psychotherapies are effective treatments for comorbid MDD, and the introduction of lifestyle interventions as well as collaborative care models and digital technologies provide promising strategies for improving management. This paper aims to provide a detailed overview of the epidemiology of the comorbidity of MDD and specific physical diseases, including prevalence and bidirectional risk; of shared biological pathways potentially implicated in the pathogenesis of MDD and common physical diseases; of socio-environmental factors that serve as both shared risk and protective factors; and of management of MDD and physical diseases, including prevention and treatment. We conclude with future directions and emerging research related to optimal care of people with comorbid MDD and physical diseases.

Body mass index and inflammation in depression and treatment-resistant depression: a Mendelian randomisation study

BACKGROUND

Major depressive disorder (MDD) has a significant impact on global burden of disease. Complications in clinical management can occur when response to pharmacological modalities is considered inadequate and symptoms persist (treatment-resistant depression (TRD)). We aim to investigate inflammation, proxied by C-reactive protein (CRP) levels, and body mass index (BMI) as putative causal risk factors for depression and subsequent treatment resistance, leveraging genetic information to avoid confounding via Mendelian randomisation (MR).

METHODS

We used the European UK Biobank subcohort ([Formula: see text]), the mental health questionnaire (MHQ) and clinical records. For treatment resistance, a previously curated phenotype based on general practitioner (GP) records and prescription data was employed. We applied univariable and multivariable MR models to genetically predict the exposures and assess their causal contribution to a range of depression outcomes. We used a range of univariable, multivariable and mediation MR models techniques to address our research question with maximum rigour. In addition, we developed a novel statistical procedure to apply pleiotropy-robust multivariable MR to one sample data and employed a Bayesian bootstrap procedure to accurately quantify estimate uncertainty in mediation analysis which outperforms standard approaches in sparse binary outcomes. Given the flexibility of the one-sample design, we evaluated age and sex as moderators of the effects.

RESULTS

In univariable MR models, genetically predicted BMI was positively associated with depression outcomes, including MDD ([Formula: see text] ([Formula: see text] CI): 0.133(0.072, 0.205)) and TRD (0.347(0.002, 0.682)), with a larger magnitude in females and with age acting as a moderator of the effect of BMI on severity of depression (0.22(0.050, 0.389)). Multivariable MR analyses suggested an independent causal effect of BMI on TRD not through CRP (0.395(0.004, 0.732)). Our mediation analyses suggested that the effect of CRP on severity of depression was partly mediated by BMI. Individuals with TRD ([Formula: see text]) observationally had higher CRP and BMI compared with individuals with MDD alone and healthy controls.

DISCUSSION

Our work supports the assertion that BMI exerts a causal effect on a range of clinical and questionnaire-based depression phenotypes, with the effect being stronger in females and in younger individuals. We show that this effect is independent of inflammation proxied by CRP levels as the effects of CRP do not persist when jointly estimated with BMI. This is consistent with previous evidence suggesting that overweight contributed to depression even in the absence of any metabolic consequences. It appears that BMI exerts an effect on TRD that persists when we account for BMI influencing MDD.

Obesity as a causal risk factor for depression: Systematic review and meta-analysis of Mendelian Randomization studies and implications for population mental health

BACKGROUND/OBJECTIVES

Obesity has been associated with elevated risk of depression. If this association is causal, the increasing obesity prevalence might lead to worsening population mental health, but the strength of the causal effect has not been systematically evaluated.

SUBJECTS/METHODS

The current study provides a systematic review and meta-analysis of studies examining associations between body mass index and depression using Mendelian randomization with multiple genetic variants as instruments for body mass index. We used this estimate to calculate the expected changes in prevalence of population psychological distress from the 1990s-2010s, which were compared with the empirically observed trends in psychological distress in the Health Survey for England (HSE) and U.S. National Health Interview Surveys (NHIS).

RESULTS

Meta-analysis of 8 Mendelian randomization studies indicated an OR = 1.33 higher depression risk associated with obesity (95% confidence interval 1.19, 1.48). Between 15% and 20% of the participants of HSE and NHIS reported at least moderate psychological distress. The increase of obesity prevalence from the 1990s-2010s in HSE and NHIS would have led to a 0.6 percentage-point increase in population psychological distress.

CONCLUSIONS

Mendelian randomization studies suggest that obesity is a causal risk factor for elevated risk of depression. The increasing obesity rates may have modestly increased the prevalence of depressive symptoms in the general population. Mendelian randomization relies on methodological assumptions that may not always hold, so other quasi-experimental methods are needed to confirm the current conclusions.

Shared biological mechanisms of depression and obesity: focus on adipokines and lipokines

Depression and obesity are both common disorders currently affecting public health, frequently occurring simultaneously within individuals, and the relationship between these disorders is bidirectional. The association between obesity and depression is highly co-morbid and tends to significantly exacerbate metabolic and related depressive symptoms. However, the neural mechanism under the mutual control of obesity and depression is largely inscrutable. This review focuses particularly on alterations in systems that may mechanistically explain the in vivo homeostatic regulation of the obesity and depression link, such as immune-inflammatory activation, gut microbiota, neuroplasticity, HPA axis dysregulation as well as neuroendocrine regulators of energy metabolism including adipocytokines and lipokines. In addition, the review summarizes potential and future treatments for obesity and depression and raises several questions that need to be answered in future research. This review will provide a comprehensive description and localization of the biological connection between obesity and depression to better understand the co-morbidity of obesity and depression.

Dissecting the causal association between social or physical inactivity and depression: a bidirectional two-sample Mendelian Randomization study

A growing body of research suggests that social or physical activity can affect the risk of Major depressive disorder (MDD). However, the bidirectional relationship between them remains to be clarified further, especially between inactivity and MDD. Here, we performed a two-sample Mendelian Randomization analysis using genetic variants associated with social/physical activities and MDD, and assessed the mediating effect of obesity-related measures and brain imaging phenotypes. The dataset on MDD, social activities, and physical activities included 500,199; 461,369; 460,376 individuals, respectively. Information regarding body mass index (BMI), body fat percentage (BFP), IDPs for 454,633; 461,460; 8,428 participants, respectively. We identified bidirectional causal relationships between sport clubs or gyms, strenuous sports, heavy do-it-youself, other exercises and MDD. We also observed that leisure/social inactivity (odds ratio [OR] = 1.64; P = 5.14 × 10-5) or physical inactivity (OR = 3.67; P = 1.99 × 10-5) caused an increased risk of MDD, which were partially mediated by BMI or BFP and masked by the weighted-mean orientation dispersion index of left acoustic radiation or volume of right caudate. Furthermore, we discovered that MDD increased the risk of leisure/social inactivity (OR = 1.03; P = 9.89 × 10-4) or physical inactivity (OR = 1.01; P = 7.96 × 10-4). In conclusions, we found that social/physical activities reduced the risk of MDD, while MDD in turn hindered social/physical activities. Inactivity may increase the risk of MDD, which was mediated or masked by brain imaging phenotypes. These results help to understand the manifestations of MDD and provide evidence and direction for the advancement of intervention and prevention.

Appropriate Macronutrients or Mineral Elements Are Beneficial to Improve Depression and Reduce the Risk of Depression

Depression is a common mental disorder that seriously affects the quality of life and leads to an increasing global suicide rate. Macro, micro, and trace elements are the main components that maintain normal physiological functions of the brain. Depression is manifested in abnormal brain functions, which are considered to be tightly related to the imbalance of elements. Elements associated with depression include glucose, fatty acids, amino acids, and mineral elements such as lithium, zinc, magnesium, copper, iron, and selenium. To explore the relationship between these elements and depression, the main literature in the last decade was mainly searched and summarized on PubMed, Google Scholar, Scopus, Web of Science, and other electronic databases with the keywords "depression, sugar, fat, protein, lithium, zinc, magnesium, copper, iron, and selenium". These elements aggravate or alleviate depression by regulating a series of physiological processes, including the transmission of neural signals, inflammation, oxidative stress, neurogenesis, and synaptic plasticity, which thus affect the expression or activity of physiological components such as neurotransmitters, neurotrophic factors, receptors, cytokines, and ion-binding proteins in the body. For example, excessive fat intake can lead to depression, with possible mechanisms including inflammation, increased oxidative stress, reduced synaptic plasticity, and decreased expression of 5-Hydroxytryptamine (5-HT), Brain Derived Neurotrophic Factor (BDNF), Postsynaptic density protein 95(PSD-95), etc. Supplementing mineral elements, such as selenium, zinc, magnesium, or lithium as a psychotropic medication is mostly used as an auxiliary method to improve depression with other antidepressants. In general, appropriate nutritional elements are essential to treat depression and prevent the risk of depression.

The impact of obesity: a narrative review

Obesity is a disease with a major negative impact on human health. However, people with obesity may not perceive their weight to be a significant problem and less than half of patients with obesity are advised by their physicians to lose weight. The purpose of this review is to highlight the importance of managing overweight and obesity by discussing the adverse consequences and impact of obesity. In summary, obesity is strongly related to >50 medical conditions, with many of them having evidence from Mendelian randomisation studies to support causality. The clinical, social and economic burdens of obesity are considerable, with these burdens potentially impacting future generations as well. This review highlights the adverse health and economic consequences of obesity and the importance of an urgent and concerted effort towards the prevention and management of obesity to reduce the burden of obesity.

Prediction of Suicidal Behaviors in the Middle-aged Population: Machine Learning Analyses of UK Biobank

BACKGROUND

Suicidal behaviors, including suicide deaths and attempts, are major public health concerns. However, previous suicide models required a huge amount of input features, resulting in limited applicability in clinical practice.

OBJECTIVE

We aimed to construct applicable models (ie, with limited features) for short- and long-term suicidal behavior prediction. We further validated these models among individuals with different genetic risks of suicide.

METHODS

Based on the prospective cohort of UK Biobank, we included 223 (0.06%) eligible cases of suicide attempts or deaths, according to hospital inpatient or death register data within 1 year from baseline and randomly selected 4460 (1.18%) controls (1:20) without such records. We similarly identified 833 (0.22%) cases of suicidal behaviors 1 to 6 years from baseline and 16,660 (4.42%) corresponding controls. Based on 143 input features, mainly including sociodemographic, environmental, and psychosocial factors; medical history; and polygenic risk scores (PRS) for suicidality, we applied a bagged balanced light gradient-boosting machine (LightGBM) with stratified 10-fold cross-validation and grid-search to construct the full prediction models for suicide attempts or deaths within 1 year or between 1 and 6 years. The Shapley Additive Explanations (SHAP) approach was used to quantify the importance of input features, and the top 20 features with the highest SHAP values were selected to train the applicable models. The external validity of the established models was assessed among 50,310 individuals who participated in UK Biobank repeated assessments both overall and by the level of PRS for suicidality.

RESULTS

Individuals with suicidal behaviors were on average 56 years old, with equal sex distribution. The application of these full models in the external validation data set demonstrated good model performance, with the area under the receiver operating characteristic (AUROC) curves of 0.919 and 0.892 within 1 year and between 1 and 6 years, respectively. Importantly, the applicable models with the top 20 most important features showed comparable external-validated performance (AUROC curves of 0.901 and 0.885) as the full models, based on which we found that individuals in the top quintile of predicted risk accounted for 91.7% (n=11) and 80.7% (n=25) of all suicidality cases within 1 year and during 1 to 6 years, respectively. We further obtained comparable prediction accuracy when applying these models to subpopulations with different genetic susceptibilities to suicidality. For example, for the 1-year risk prediction, the AUROC curves were 0.907 and 0.885 for the high (>2nd tertile of PRS) and low (<1st) genetic susceptibilities groups, respectively.

CONCLUSIONS

We established applicable machine learning-based models for predicting both the short- and long-term risk of suicidality with high accuracy across populations of varying genetic risk for suicide, highlighting a cost-effective method of identifying individuals with a high risk of suicidality.

Longitudinal association between cardiovascular risk factors and depression in young people: a systematic review and meta-analysis of cohort studies

BACKGROUND

Depression is a common and serious mental illness that begins early in life. An association between cardiovascular disease (CVD) and subsequent depression is clear in adults. We examined associations between individual CVD risk factors and depression in young people.

METHODS

We searched MEDLINE, EMBASE, and PsycINFO databases from inception to 1 January 2020. We extracted data from cohort studies assessing the longitudinal association between CVD risk factors [body mass index (BMI), smoking, systolic blood pressure (SBP), total cholesterol, high-density lipoprotein] and depression, measured using a validated tool in individuals with mean age of 24 years or younger. Random effect meta-analysis was used to combine effect estimates from individual studies, including odds ratio (OR) for depression and standardised mean difference for depressive symptoms.

RESULTS

Based on meta-analysis of seven studies, comprising 15 753 participants, high BMI was associated with subsequent depression [pooled OR 1.61; 95% confidence interval (CI) 1.21-2.14; I2 = 31%]. Based on meta-analysis of eight studies, comprising 30 539 participants, smoking was associated with subsequent depression (pooled OR 1.73; 95% CI 1.36-2.20; I2 = 74%). Low, but not high, SBP was associated with an increased risk of depression (pooled OR 3.32; 95% CI 1.68-6.55; I2 = 0%), although this was based on a small pooled high-risk sample of 893 participants. Generalisability may be limited as most studies were based in North America or Europe.

CONCLUSIONS

Targeting childhood/adolescent smoking and obesity may be important for the prevention of both CVD and depression across the lifespan. Further research on other CVD risk factors including blood pressure and cholesterol in young people is required.

Mendelian randomisation study of body composition and depression in people of East Asian ancestry highlights potential setting-specific causality

BACKGROUND

Extensive evidence links higher body mass index (BMI) to higher odds of depression in people of European ancestry. However, our understanding of the relationship across different settings and ancestries is limited. Here, we test the relationship between body composition and depression in people of East Asian ancestry.

METHODS

Multiple Mendelian randomisation (MR) methods were used to test the relationship between (a) BMI and (b) waist-hip ratio (WHR) with depression. Firstly, we performed two-sample MR using genetic summary statistics from a recent genome-wide association study (GWAS) of depression (with 15,771 cases and 178,777 controls) in people of East Asian ancestry. We selected 838 single nucleotide polymorphisms (SNPs) correlated with BMI and 263 SNPs correlated with WHR as genetic instrumental variables to estimate the causal effect of BMI and WHR on depression using the inverse-variance weighted (IVW) method. We repeated these analyses stratifying by home location status: China versus UK or USA. Secondly, we performed one-sample MR in the China Kadoorie Biobank (CKB) in 100,377 participants. This allowed us to test the relationship separately in (a) males and females and (b) urban and rural dwellers. We also examined (c) the linearity of the BMI-depression relationship.

RESULTS

Both MR analyses provided evidence that higher BMI was associated with lower odds of depression. For example, a genetically-instrumented 1-SD higher BMI in the CKB was associated with lower odds of depressive symptoms [OR: 0.77, 95% CI: 0.63, 0.95]. There was evidence of differences according to place of residence. Using the IVW method, higher BMI was associated with lower odds of depression in people of East Asian ancestry living in China but there was no evidence for an association in people of East Asian ancestry living in the USA or UK. Furthermore, higher genetic BMI was associated with differential effects in urban and rural dwellers within China.

CONCLUSIONS

This study provides the first MR evidence for an inverse relationship between BMI and depression in people of East Asian ancestry. This contrasts with previous findings in European populations and therefore the public health response to obesity and depression is likely to need to differ based on sociocultural factors for example, ancestry and place of residence. This highlights the importance of setting-specific causality when using genetic causal inference approaches and data from diverse populations to test hypotheses. This is especially important when the relationship tested is not purely biological and may involve sociocultural factors.

‘I don't know which is the chicken and which is the egg’: A qualitative study of weight loss‐related beliefs and behaviours among adults with psoriasis and comorbid obesity

OBJECTIVES

Obesity is a common (30%-40%) comorbidity of psoriasis. Weight loss is shown to improve the severity of psoriasis; however, little is known about the factors that may influence successful weight loss in the context of obesity and psoriasis. The current qualitative study aimed to explore the obesity-associated beliefs, perceptions, and behaviours related to weight loss in psoriasis. Preferences for a weight loss intervention were also explored.

DESIGN

Qualitative in-depth semi-structured interviews were conducted with 24 adults (62.5% male) with moderate-to-severe psoriasis and obesity (mean body mass index = 35.2 kg/m² , SD = 4.1), recruited through a patient organization website in the UK. Data were analysed using inductive thematic analysis.

RESULTS

Most participants viewed psoriasis as unrelated to obesity. A well-controlled psoriasis and improvements in psoriasis symptoms were considered as major motivators for engaging in a weight loss program by individuals who viewed psoriasis and obesity as related conditions. Comfort eating was perceived as an escape strategy from the psoriasis-induced negative emotions. Participants shared their dissatisfaction with current weight loss recommendations which were too generic. They suggested that a desirable weight loss program would require both emotional and behavioural support, with an emphasis on psoriasis' burden.

CONCLUSION

The findings accentuate the importance of (1) clinicians discussing the link between obesity and psoriasis with patients, (2) weight loss advice to include both behavioural and emotional support, and (3) a weight loss advice to consider the psoriasis burden and the perceived barriers which may potentially lead to improved outcomes to obesity management in psoriasis.

Mendelian randomization analysis identified causal Association of Childhood Obesity with adult major depressive disorder

BACKGROUND

Childhood obesity is associated with adult major depressive disorder (MDD), but their causality is not clear.

METHODS

We performed a two-sample Mendelian randomization (MR) analysis to explore the causality of childhood body mass index (BMI) and childhood obesity on MDD, followed by a multivariable MR (MVMR) analysis to investigate the potential role of adult BMI in mediating such effect. We accessed genome-wide association summary statistics of childhood BMI, childhood obesity, adult BMI and adult MDD from the Early Growth Genetics consortium (n_BMI  = 47 541, n_obesity  = 24 160), the Genetic Investigation of Anthropometric Traits consortium (n_{adult_BMI}  = ∼700 000) and the Psychiatric Genomics consortium (n_MDD  = 500 199), respectively. The MR-PRESSO test was performed to remove SNPs with potential pleiotropic effect. The MR analysis was performed by inverse-variance weighted test. Further sensitivity analyses, including the MR-Egger intercept test and leave-one-out analysis, were performed to evaluate the reliability of the results.

RESULTS

Our study found that childhood obesity might increase the odds of developing MDD in adults (OR = 1.03, 95% CI: 1.01-1.06, p = 2.6 × 10^-3 ). Children with higher BMI were more likely to develop MDD in adulthood, with an OR of 1.12 per standard deviation score (SDS) increase in BMI (95% CI: 1.07-1.17, p = 4.4 × 10^-7 ). Sensitivity analyses verified the reliability of the causality between childhood BMI/obesity and MDD. Further MVMR results revealed that the impact of childhood BMI on MDD risk was predominantly mediated by adult BMI.

CONCLUSION

Our findings provided evidence of a causal relationship between childhood BMI/obesity and adult MDD, thus providing new insights into the prevention of MDD.

Obesity, type 2 diabetes, and testosterone in ageing men

In the absence of obesity, adverse lifestyle behaviours, and use of medication such as opioids serum testosterone concentrations decrease by only a minimal amount at least until very advanced age in most men. Obesity is heterogeneous in its phenotype, and it is the accumulation of excess adipose tissue viscerally associated with insulin resistance, dyslipidaemia, inflammation, hypothalamic leptin resistance and gliosis that underpins the functional hypogonadism of obesity. Both central (hypothalamic) and peripheral mechanisms are involved resulting in a low serum total testosterone concentration, while LH and FSH are typically in the normal range. Peripherally a decrease in serum sex hormone binding globulin (SHBG) concentration only partially explains the decrease in testosterone and there is increasing evidence for direct effects in the testis. Men with obesity associated functional hypogonadism and serum testosterone concentrations below 16 nmol/L are at increased risk of incident type 2 diabetes (T2D); high testosterone concentrations are protective. The magnitude of weight loss is linearly associated with an increase in serum testosterone concentration and with the likelihood of preventing T2D or reverting newly diagnosed disease; treatment with testosterone for 2 years increases the probability of a positive outcome from a lifestyle intervention alone by approximately 40%. Whether the additional favourable benefits of testosterone treatment on muscle mass and strength and bone density and quality in the long-term remains to be determined.

The importance of illness severity and multimorbidity in the association between mental health and body weight in psoriasis: Cross-sectional and longitudinal analysis

Background

High body weight is common in psoriasis and is associated with depression and anxiety. Past studies are mostly cross-sectional and may underestimate the role of demographic and illness-related factors in the association between mental health and body weight in psoriasis.

Objectives

This study explored the association between depression and anxiety with waist circumference and body mass index (BMI) cross-sectionally and at 12 months follow-up, adjusting for demographic and illness-related factors in people with psoriasis.

Method

Routine psoriasis care data were combined with data on depression and anxiety from a large specialist psoriasis centre. The analytical samples consisted of patients with complete data on either waist circumference (N = 326 at time 1; N = 191 at follow-up) or BMI (N = 399 at time 1; N = 233 at follow-up) and corresponding mental health, demographic, and illness-related information. Associations between weight-related outcomes and mental health variables were assessed at time one and at 12 months follow-up, after adjusting for demographic and illness-related factors.

Results

We found no evidence of associations between mental health and waist circumference or BMI, after adjusting for age, gender and illness-related factors. Higher age, male gender and illness-related factors, specifically multimorbidity and psoriasis severity, were positively associated with waist circumference and BMI at both time points.

Conclusion

This study revealed the important role of factors related to illness severity in body weight in psoriasis. The contribution of depression and anxiety to weight was not observed here likely due to the sample and methodology used. Future work should explore other psychosocial factors such as weight-related attitudes and emotional eating in the context of weight in psoriasis, to help inform the development of successful weight-management treatments.

Genetic and Environmental Contribution to the Co-Occurrence of Endocrine-Metabolic Disorders and Depression: A Nationwide Swedish Study of Siblings

OBJECTIVE

Depression is common in individuals with endocrine-metabolic disorders and vice versa, and a better understanding of the underlying factors contributing to the comorbidity of these disorders is needed. This study investigated the familial coaggregation of depression and endocrine-metabolic disorders and estimated the contribution of genetic and environmental factors to their co-occurrence.

METHODS

This population-based cohort study included 2.2 million individuals born in Sweden between 1973 and 1996, with follow-up through 2013. Participants were linked to their biological parents, allowing identification of full siblings, maternal half siblings, and paternal half siblings. Diagnoses of depression and endocrine-metabolic conditions were investigated, with the latter grouped into autoimmune disorders (autoimmune hypothyroidism, Graves' disease, and type 1 diabetes) and non-autoimmune disorders (type 2 diabetes, obesity, and polycystic ovary syndrome). Logistic regression and Cox regression were used to estimate the associations between endocrine-metabolic disorders and depression within the same individual and across siblings. Quantitative genetic modeling was performed to investigate the relative contribution of genetic and environmental influences.

RESULTS

Individuals with endocrine-metabolic disorders had a significantly higher risk of depression, with odds ratios ranging from 1.43 (95% CI=1.30, 1.57) for Graves' disease to 3.48 (95% CI=3.25, 3.72) for type 2 diabetes. Increased risks extended to full and half siblings. These correlations were mainly explained by shared genetic influences for non-autoimmune conditions, and by nonshared environmental factors for autoimmune disorders, especially for type 1 diabetes.

CONCLUSIONS

These findings provide phenotypic and etiological insights into the co-occurrence of depression and various endocrine-metabolic conditions, which could guide future research aiming at identifying pathophysiological mechanisms and intervention targets.

Overweight, obesity, and individual symptoms of depression: A multicohort study with replication in UK Biobank

OBJECTIVES

Obesity is associated with increased risk of depression, but the extent to which this association is symptom-specific is unknown. We examined the associations of overweight and obesity with individual depressive symptoms.

METHODS

We pooled data from 15 population-based cohorts comprising 57,532 individuals aged 18 to 100 years at study entry. Primary analyses were replicated in an independent cohort, the UK Biobank study (n = 122,341, age range 38 to 72). Height and weight were assessed at baseline and body mass index (BMI) was computed. Using validated self-report measures, 24 depressive symptoms were ascertained once in 16 cross-sectional, and twice in 7 prospective cohort studies (mean follow-up 3.2 years).

RESULTS

In the pooled analysis of the primary cohorts, 22,045 (38.3 %) participants were overweight (BMI between 25 and 29.9 kg/m2), 12,025 (20.9 %) class I obese (BMI between 30 and 34.9 kg/m2), 7,467 (13.0 %) class II-III obese (BMI ≥ 35 kg/m2); and 7,046 (12.3 %) were classified as depressed. After multivariable adjustment, obesity class I was cross-sectionally associated with 1.11-fold (95 % confidence interval 1.01-1.22), and obesity class II-III with 1.31-fold (1.16-1.49) higher odds of overall depression. In symptom-specific analyses, robust associations were apparent for 4 of the 24 depressive symptoms ('could not get going/lack of energy', 'little interest in doing things', 'feeling bad about yourself, and 'feeling depressed'), with confounder-adjusted odds ratios of having 3 or 4 of these symptoms being 1.32 (1.10-1.57) for individuals with obesity class I, and 1.70 (1.34-2.14) for those with obesity class II-III. Elevated C-reactive protein and 21 obesity-related diseases explained 23 %-31 % of these associations. Symptom-specific associations were confirmed in longitudinal analyses where obesity preceded symptom onset, were stronger in women compared with men, and were replicated in UK Biobank.

CONCLUSIONS

Obesity is associated with a distinct set of depressive symptoms. These associations are partially explained by systemic inflammation and obesity-related morbidity. Awareness of this obesity-related symptom profile and its underlying biological correlates may inform better targeted treatments for comorbid obesity and depression.

Social jetlag and depression in female rotating-shift nurses: A secondary analysis

PURPOSE

This study aimed to identify the predictors of depression among female rotating-shift nurses.

DESIGN AND METHODS

This secondary data analysis used data of 190 Korean female rotating-shift nurses from the parent study conducted in 2018. A multiple logistic regression analysis was performed to identify the predictors of depression.

FINDINGS

Young age, poor sleep quality, and greater morning-shift social jetlag predicted depression among female nurses working a three-shift schedule.

PRACTICE IMPLICATIONS

Nursing management should consider scheduling shifts to minimize nurses' social jetlag and develop interventions for improving sleep quality to prevent depression among female rotating-shift nurses.

Mental Health Symptom Reduction Using Digital Therapeutics Care Informed by Genomic SNPs and Gut Microbiome Signatures

Neuropsychiatric diseases and obesity are major components of morbidity and health care costs, with genetic, lifestyle, and gut microbiome factors linked to their etiology. Dietary and weight-loss interventions can help improve mental health, but there is conflicting evidence regarding their efficacy; and moreover, there is substantial interindividual heterogeneity that needs to be understood. We aimed to identify genetic and gut microbiome factors that explain interindividual differences in mental health improvement after a dietary and lifestyle intervention for weight loss. We recruited 369 individuals participating in Digbi Health’s personalized digital therapeutics care program and evaluated the association of 23 genetic scores, the abundance of 178 gut microbial genera, and 42 bacterial pathways with mental health. We studied the presence/absence of anxiety or depression, or sleep problems at baseline and improvement on anxiety, depression, and insomnia after losing at least 2% body weight. Participants lost on average 5.4% body weight and >95% reported improving mental health symptom intensity. There were statistically significant correlations between: (a) genetic scores with anxiety or depression at baseline, gut microbial functions with sleep problems at baseline, and (b) genetic scores and gut microbial taxa and functions with anxiety, depression, and insomnia improvement. Our results are concordant with previous findings, including the association between anxiety or depression at baseline with genetic scores for alcohol use disorder and major depressive disorder. As well, our results uncovered new associations in line with previous epidemiological literature. As evident from previous literature, we also observed associations of gut microbial signatures with mental health including short-chain fatty acids and bacterial neurotoxic metabolites specifically with depression. Our results also show that microbiome and genetic factors explain self-reported mental health status and improvement better than demographic variables independently. The genetic and microbiome factors identified in this study provide the basis for designing and personalizing dietary interventions to improve mental health.

Genetics in psychiatry: Methods, clinical applications and future perspectives

Psychiatric disorders and related traits have a demonstrated genetic component, with heritability estimated by twin studies generally between 80% and 40%. Their pathogenesis is complex and multi-determined: environmental factors interact with a polygenic architecture, making difficult the development of models able to stratify patients or predict mental health outcomes. Despite this difficult challenge, relevant progress has been made in the field of psychiatric genetics in recent years. This review aims to present the main current methods in psychiatric genetics, their output, limitations, clinical applications, and possible future developments. Genome-wide association studies (GWASs) performed in increasingly large samples have led to the identification of replicated genetic loci associated with the risk of major psychiatric disorders, including schizophrenia and mood disorders. Statistical and biological approaches have been developed to improve our understanding of the etiopathogenetic mechanisms behind genome-wide significant associations, as well as for estimating the cumulative effect of risk variants at the individual level and the genetic overlap between different disorders, as pleiotropy is the rule rather than the exception. Clinical applications are available in the pharmacogenetics field. The main issues that remain to be addressed include improving ethnic diversity in genetic studies and the optimization of statistical power through methodological improvements, such as the definition of dimensional phenotypes with specific biological correlates and the integration of different types of omics data.

The impact of obesity-related neuroinflammation on postpartum depression: A narrative review

Obesity is currently one of the most serious health problems, affecting 13% of the world's adult population. Obesity is characterized by persistent low-grade chronic inflammation that assumes systemic proportions and triggers several associated metabolic diseases. Furthermore, obesity has been associated with an increased occurrence of central disorders such as impaired cognitive function, reward system dysfunction, and depression. In summary, there is a quantitative reduction in the release of neurotransmitters in depression. Postsynaptic cells capture lower concentrations of neurotransmitters, which leads to a functional reduction in the central nervous system (CNS). Globally, approximately 15-65% of women experience depressive symptoms during pregnancy, depending on their location. Depressive symptoms persist in some women, leading to postpartum depression (PPD). Thus, obesity may be considered a risk factor for PPD development. This study aimed to synthesize studies on the impact of obesity-related neuroinflammation and PPD. We conducted a narrative review of the relevant literature. The search was performed in electronic databases, specifically PubMed, selecting articles in English published from 2014 to 2021 using the narrative review methodology.

The role of body fat in multiple sclerosis susceptibility and severity: A Mendelian randomisation study

OBJECTIVE

The objective of this study was to explore the potential causal associations of body mass index, height, weight, fat mass, fat percentage and non-fat mass in the whole body, arms, legs and trunk (henceforth, 'anthropometric measures') with multiple sclerosis (MS) risk and severity. We also investigated the potential for reverse causation between anthropometric measures and MS risk.

METHODS

We conducted a two-sample univariable, multivariable and bidirectional Mendelian randomisation (MR) analysis.

RESULTS

A range of features linked to obesity (body mass index, weight, fat mass and fat percentage) were risk factors for MS development and worsened the disease's severity in MS patients. Interestingly, we were able to demonstrate that height and non-fat mass have no association with MS risk or MS severity. We demonstrated that the association between anthropometric measures and MS is not subject to bias from reverse causation.

CONCLUSIONS

Our findings provide evidence from human genetics that a range of features linked to obesity is an important contributor to MS development and MS severity, but height and non-fat mass are not. Importantly, these findings also identify a potentially modifiable factor that may reduce the accumulation of further disability and ameliorate MS severity.

Association of Physical Performance, Muscle Strength and Body Composition with Self-Assessed Quality of Life in Hemodialyzed Patients: A Cross-Sectional Study

(1) Patients on chronic hemodialysis (HD) experience impaired quality of life (QoL). We analyzed HD’s relationship with physical performance, body composition, and muscle strength; (2) QoL was assessed with the Short Form-36, composed of physical (PCS) and mental (MCS) health dimensions. Physical performance was assessed with the Short Physical Performance Battery (SPPB), body composition (lean tissue mass% (LTM%), fat tissue mass% (FTM%), and skeletal muscle mass% (SMM%)) was assessed with bioelectrical impedance, and lower extremity strength was assessed with a handheld dynamometer; and (3) we enrolled 76 patients (27 F, 49 M), age 62.26 ± 12.81 years, HD vintage 28.45 (8.65−77.49) months. Their QoL score was 53.57 (41.07−70.64); their PCS and MCS scores were 52.14 (38.69−65.95) and 63.39 (44.64−76.79) and strongly correlated (p < 0.0001, R = 0.738). QoL correlated positively with SPPB (R = 0.35, p ≤ 0.001), muscle strength (R from 0.21 to 0.41, p < 0.05), and LTM% (R = 0.38, p < 0.001) and negatively with FTM% (R = −0.32, p = 0.006). PCS correlated positively with SPPB (R = 0.42 p < 0.001), muscle strength (R 0.25−0.44, p < 0.05), and LTM% (R = 0.32, p = 0.006) and negatively with FTM% (R = −0.25, p = 0.031). MCS correlated positively with SPPB (R = 0.23, p = 0.047), SMM% (R = 0.25; p = 0.003), and LTM% (R = 0.39, p < 0.001) and negatively with FTM% (R = −0.34; p = 0.003). QoL was unrelated to sex (p = 0.213), age (p = 0.157), HD vintage (p = 0.156), and BMI (p = 0.202); (4) Better physical performance, leaner body composition, and higher muscle strength are associated with better mental and physical QoL in HD.

Socioeconomic status, individual behaviors and risk for mental disorders: A Mendelian randomization study

BACKGROUND

There is increasing attention on the association of socioeconomic status and individual behaviors (SES/IB) with mental health. However, the impacts of SES/IB on mental disorders are still unclear. To provide evidence for establishing feasible strategies on disease screening and prevention, we implemented Mendelian randomization (MR) design to appraise causality between SES/IB and mental disorders.

METHODS

We conducted a two-sample MR study to assess the causal effects of SES and IB (dietary habits, habitual physical activity, smoking behaviors, drinking behaviors, sleeping behaviors, leisure sedentary behaviors, risky behaviors, and reproductive behaviors) on three mental disorders, including bipolar disorder, major depressive disorder and schizophrenia. A series of filtering steps were taken to select eligible genetic instruments robustly associated with each of the traits. Inverse variance weighted was used for primary analysis, with alternative MR methods including MR-Egger, weighted median, and weighted mode estimate. Complementary methods were further used to detect pleiotropic bias.

RESULTS

After Bonferroni correction and rigorous quality control, we identified that SES (educational attainment), smoking behaviors (smoking initiation, number of cigarettes per day), risky behaviors (adventurousness, number of sexual partners, automobile speeding propensity) and reproductive behavior (age at first birth) were causally associated with at least one of the mental disorders.

CONCLUSIONS

MR study provides robust evidence that SES/IB play broad impacts on mental disorders.

Abnormal dynamic functional connectivity in first-episode, drug-naïve adolescents with major depressive disorder

Previous neuroimaging studies have identified disrupted large-scale functional brain networks in major depressive disorder (MDD); however, most of them focused on adult patients and were based on static functional connectivity (FC). Thus, we aimed to investigate the patterns of change in dynamic FC in depressed adolescents. Resting-state functional magnetic resonance imaging data were acquired from 60 first-episode, drug-naïve adolescents with MDD and 60 matched healthy controls (HCs). Then, the dynamic FC properties were analyzed using a sliding windows approach, k-means clustering, and graph theory methods. The intrinsic brain FC were clustered into two configuration states-a more frequent and relatively sparsely connected State 1 and a less frequent and more strongly interconnected State 2. Compared with HCs, depressed adolescents had higher reoccurrence fraction and dwell time in State 1, and lower reoccurrence fraction and dwell time in State 2, and higher total number of transitions between the two states. Depressed adolescents showed decreased FC within the default mode network (DMN) and between the DMN and other networks in State 1. Additionally, the MDD group showed higher variances in the global and local efficiency. Furthermore, the duration of illness was positively correlated with the number of state transitions, and the 17-item Hamilton Depression Rating Scale score was positively correlated with the mean dwell time in State 1. This study demonstrated abnormal dynamic FC in depressed adolescents, which provided new insights into the pathophysiological mechanisms of adolescent-onset depression.

Food addiction comorbid to mental disorders in adolescents: a nationwide survey and register-based study

PURPOSE

Adolescence is a high-risk period for development of addictive behavior. This may also apply to addiction-like eating of highly processed foods-commonly referred to as "food addiction". Adolescents with mental disorder may be at particularly elevated risk of developing food addiction as addiction often accompanies mental disorder. However, there are only few studies in adolescents investigating this potential comorbidity. Therefore, the primary aim of this study was to examine the food addiction symptom load, as measured by the dimensional Yale Food Addiction Scale for Children-version 2.0 (dYFAS-C 2.0), among adolescents with a clinically verified mental disorder.

METHOD

A total of 3529 adolescents aged 13-17 were drawn from the Danish Psychiatric Central Research Register, stratified on six major diagnostic categories of mental disorders; psychotic disorders, affective disorders, anxiety disorders, eating disorders, autism spectrum disorders, and attention deficit disorders. Via their parents, these adolescents were invited to participate in a web-based survey. Data on health and socioeconomic factors from the Danish registers were linked to both respondents and non-respondents, allowing for thorough attrition analysis and estimation of weighted dYFAS-C 2.0 scores.

RESULTS

A total of 423 adolescents participated in the survey (response rate 12.0%). The mean weighted dYFAS-C 2.0 total score was 13.9 (95% CI 12.6; 14.9) for the entire sample and varied substantially across the diagnostic categories being highest for those with psychotic disorder, mean 18.4 (95% CI 14.6; 14.9), and affective disorders, mean 19.4. (95% CI 16.3; 22.5). Furthermore, the dYFAS-C 2.0 total score was positively correlated with body mass index (BMI) (r = 0.33, p < 0.05).

CONCLUSION

Food addiction symptomatology seems to be prevalent among adolescents with mental disorder, particularly affective and psychotic disorders. As obesity is a tremendous problem in individuals with mental disorder further investigation of food addiction in young people with mental disorder is called for. This could potentially aid in the identification of potential transdiagnostic targets for prevention and treatment of obesity in this group.

LEVEL OF EVIDENCE

Level IV, Observational cross-sectional descriptive study combined with retrospective register data.