Combined healthy lifestyles and risk of depressive symptoms: A baseline survey in China

BACKGROUND

Little evidence exists about whether a combination of healthy lifestyle factors is associated with a lower risk of depressive symptoms among Chinese population. We aimed to investigate the association between combined healthy lifestyle factors and risk of depressive symptoms.

METHODS

We conducted a baseline survey from July 2021 to December 2023, including 53,642 Chinese adults from general population. A healthy lifestyle score was constructed based on six lifestyle factors (physical activity, smoking status, alcohol consumption, diet, sleep duration, and body mass index). Logistic regression models were used to estimate odds ratios (ORs) and 95 % confidence intervals (CIs) adjusted for confounding variables.

RESULTS

Each additional healthy lifestyle score was associated with a 20 % lower risk of having depressive symptoms (OR (95 % CI): 0.80 (0.78-0.81)). Compared with individuals with ≤2 healthy lifestyle factors, individuals with all the six healthy lifestyle factors had a 58 % reduced risk of having depressive symptoms (0.42 (0.37-0.47)). After stratification by gender, education and urbanization, the significant inverse association with healthy lifestyle score was stronger in women, individuals with high education, and urban residents. Besides, the significant negative association between healthy lifestyle score and depressive symptoms remained for different severity of depressive symptoms.

LIMITATIONS

Given the cross-sectional nature of data, we cannot make causal inferences.

CONCLUSIONS

Our study indicated that adherence to healthy lifestyle factors was associated with a reduced risk of having depressive symptoms among Chinese adults. The observed associations were modified by gender, education and urbanization. These findings warrant further verification in interventional studies.

Depressive disorder, bipolar disorder, and associated factors among adults, in the Eastern part of Ethiopia

BACKGROUND

Depressive disorder is one of the severe and common mental illnesses in the general population. Bipolar disorder is a severe, persistent mental illness associated with significant morbidity and mortality. However, there is a paucity of data on the prevalence of depressive disorder, and bipolar disorder in our study area.

OBJECTIVE

This study aimed to assess the prevalence of depressive and bipolar disorders among adults in Kersa, Haramaya, and Harar Health and Demographic Surveillance Sites in Eastern Ethiopia.

METHODS

A community-based cross-sectional study was conducted among 1,416 participants. A multi-stage sampling was employed to select the participants. DSM-5 diagnostic criteria was used to assess depressive disorder and bipolar disorder. Data was collected using a standard questionnaire. Data were entered into Epi-Data 3.1 and analyzed using SPSS version 26. Both binary and multivariate logistic regression analyses were done. Those with a p-value < 0.05 in the final model were considered statistically significant.

RESULTS

The overall prevalence of depressive and bipolar disorders among our study participants was 6.7% (95% CI: 5.40, 8.20) and 2.1% (95% CI: (1.40, 3.00), respectively. The independent predictors of depressive disorder included a family history of mental illness, chronic medical illnesses, unemployment, low educational status, divorced or widowed, poor social support, and current alcohol use or khat chewing. Single, males, divorced or widowed, and current consumers of alcohol were independent predictors for bipolar disorder.

CONCLUSIONS AND RECOMMENDATION

The results of our investigation showed that bipolar illness and depression were significant public health issues. It was shown that although bipolar disorder is highly prevalent in the society, depression is a widespread concern. As a result, it is imperative that the relevant body grow and enhance the provision of mental health services. Furthermore, research on the effects and burdens of bipolar disorder in the community is required.

Applications of Mendelian randomization in psychiatry: a comprehensive systematic review

Psychiatric diseases exact a heavy socioeconomic toll, and it is particularly difficult to identify their risk factors and causative mechanisms due to their multifactorial nature, the limited physiopathological insight, the many confounding factors, and the potential reverse causality between the risk factors and psychiatric diseases. These characteristics make Mendelian randomization (MR) a precious tool for studying these disorders. MR is an analytical method that employs genetic variants linked to a certain risk factor, to assess if an observational association between that risk factor and a health outcome is compatible with a causal relationship. We report the first systematic review of all existing applications and findings of MR in psychiatric disorders, aiming at facilitating the identification of risk factors that may be common to different psychiatric diseases, and paving the way to transdiagnostic MR studies in psychiatry, which are currently lacking. We searched Web of Knowledge, Scopus, and Pubmed databases (until 3 May 2022) for articles on MR in psychiatry. The protocol was preregistered in PROSPERO (CRD42021285647). We included methodological details and results from 50 articles, mainly on schizophrenia, major depression, autism spectrum disorders, and bipolar disorder. While this review shows how MR can offer unique opportunities for unraveling causal links in risk factors and etiological elements of specific psychiatric diseases and transdiagnostically, 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.

Using Mendelian randomization as the cornerstone for causal inference in epidemiology

Mendelian randomization (MR) is attracting considerable critical attention. This paper aimed to explore the characteristics of the publications of MR, to reach an insight in this field and prospect the future trend. A bibliometric analysis was performed to identify published MR-related research. The articles were selected from the Web of Science Core Collection database. Excel 2019, VOSviewer 1.6.9, and CiteSpace 5.7.R3 were used to analyze the information. A total of 1783 papers of MR were identified, and the first included literature appeared in 2003. A total of 2829 institutions from 72 countries participated in the relevant research, while the UK contributed to 852 articles and were in a leading position. The most productive institution was the University of Bristol, and Smith GD who has posted the most articles (n=202) was also from there. The Int J Epidemiol (100 publications, 6861 citations) was the most prolific and high citation journal. Related topics of frontiers will still focus on coronary heart disease, diabetes, cancer, psychiatric disorder, body mass index, and lifestyle factors. We summarized the publication information of MR-related literature from 2003 to 2020, including country and institution of origin, authors, and publication journal. We analyzed former research hotspots in the field of MR and predicted future areas of interest. Exposures and outcomes detected in this paper will be the hotspots and frontiers of research in the next few years.

Using Mendelian randomization analysis to better understand the relationship between mental health and substance use: a systematic review

BACKGROUND

Poor mental health has consistently been associated with substance use (smoking, alcohol drinking, cannabis use, and consumption of caffeinated drinks). To properly inform public health policy it is crucial to understand the mechanisms underlying these associations, and most importantly, whether or not they are causal.

METHODS

In this pre-registered systematic review, we assessed the evidence for causal relationships between mental health and substance use from Mendelian randomization (MR) studies, following PRISMA. We rated the quality of included studies using a scoring system that incorporates important indices of quality, such as the quality of phenotype measurement, instrument strength, and use of sensitivity methods.

RESULTS

Sixty-three studies were included for qualitative synthesis. The final quality rating was '-' for 16 studies, '- +' for 37 studies, and '+'for 10 studies. There was robust evidence that higher educational attainment decreases smoking and that there is a bi-directional, increasing relationship between smoking and (symptoms of) mental disorders. Another robust finding was that higher educational attainment increases alcohol use frequency, but decreases binge-drinking and alcohol use problems, and that mental disorders causally lead to more alcohol drinking without evidence for the reverse.

CONCLUSIONS

The current MR literature increases our understanding of the relationship between mental health and substance use. Bi-directional causal relationships are indicated, especially for smoking, providing further incentive to strengthen public health efforts to decrease substance use. Future MR studies should make use of large(r) samples in combination with detailed phenotypes, a wide range of sensitivity methods, and triangulate with other research methods.

Potential causal effect of posttraumatic stress disorder on alcohol use disorder and alcohol consumption in individuals of European descent: A Mendelian Randomization Study

BACKGROUND

Posttraumatic stress disorder (PTSD) often co-occurs with alcohol consumption (AC) and alcohol use disorder (AUD). However, it is unknown whether the same etiologic influences that underlie PTSD co-occurring with AUD are those that underlie PTSD and AC individually.

METHODS

This study used large-scale genome-wide association study (GWAS) data to test whether PTSD and drinks per week [DPW]/AUD are causally related to one another, and, if so, whether PTSD precedes DPW/AUD and/or vice versa. We used Mendelian Randomization methods to analyze European ancestry GWAS summary statistics from the Psychiatric Genomics Consortium (PGC; PTSD), GWAS & Sequencing Consortium of Alcohol and Nicotine Use (GSCAN; DPW), and the Million Veteran Program (MVP; AUD).

RESULTS

PTSD exerted a potentially causal effect on AUD (β = 0.039, SE = 0.014, p = 0.005), but not on DPW (β = 0.002, SE = 0.003, p = 0.414). Additionally, neither DPW (β = 0.019, SE = 0.041, p = 0.637) nor AUD (β = 8.87 × 10^-4 , SE = 0.001, p = 0.441) exerted a causal effect on PTSD.

CONCLUSIONS

These findings are consistent with the self-medication model, in which individuals misuse alcohol to cope with aversive trauma-related symptoms. These findings extend latent analysis and molecular findings of shared and correlated risk between PTSD and alcohol phenotypes. Given the health behaviors associated with these phenotypes, these findings are important in that they suggest groups to prioritize for prevention efforts. Further, they provide a rationale for future preclinical and clinical studies examining the biological mechanisms by which PTSD may impact AUD.

Effect of alcohol use disorders and alcohol intake on the risk of subsequent depressive symptoms: a systematic review and meta-analysis of cohort studies

BACKGROUND AND AIMS

Alcohol use disorders (AUD) are often comorbid with depressive symptoms. Cohort studies on the association between AUD and subsequent depressive symptoms have produced inconsistent results. Moreover, regarding alcohol intake, the risk of developing depressive symptoms might vary with alcohol intake level. We aimed to investigate the association between AUD, alcohol intake and subsequent depressive symptoms.

DESIGN AND SETTING

We conducted a systematic search in PubMed, Embase and PsycINFO for cohort studies on the association between AUD or alcohol intake and subsequent depressive symptoms.

PARTICIPANTS

We included 338 426 participants from 42 studies. Six and four studies analyzed only females and males, respectively.

MEASUREMENTS

We combined risk estimates for developing depressive symptoms using a random-effects model. We divided alcohol intake into abstinence, light (0-84 g/week), moderate (85-168 g/week) and heavy drinking (> 168 g/week or > 48 g/day at least weekly). We conducted a categorical analysis to compare the risk of depressive symptoms between abstinence and different intake categories. Further, we conducted a dose-response analysis to investigate the alcohol-depression association.

FINDINGS

We analyzed 42 studies (follow-up time: 1-40 years). AUD was associated with significantly increased risk of subsequent depressive symptoms [relative risk (RR) = 1.57, 95% confidence interval (CI) = 1.41-1.76]. Regarding alcohol intake, heavy drinking had an increased risk of depressive symptoms; however, the association was only significant when controls were limited to non-heavy drinkers (RR = 1.13, 95% CI = 1.05-1.22). Taking into consideration the possibility of publication bias and confounding factors made the association non-significant. We observed J-shaped associations in both categorical and dose-response analyses where light-moderate drinking had a significantly decreased risk of depression, while heavy drinking did not show a significant association with depressive symptoms compared with non-drinkers.

CONCLUSION

Alcohol use disorders are associated with increased the risk of subsequent depressive symptoms. Heavy drinking does not significantly predict occurrence of depressive symptoms after adjusting for potential confounders.

Moderate alcohol consumption and depression - a longitudinal population-based study in Sweden

BACKGROUND AND AIMS

The interrelationship between alcohol consumption and depression is complex, and the direction of the association is unclear. We investigated whether alcohol consumption influences the risk of depression while accounting for this potential bidirectionality.

METHODS

A total of 10 441 individuals participated in the PART study in 1998-2000, 8622 in 2001-2003, and 5228 in 2010. Participants answered questions on their alcohol consumption, symptoms of depression, childhood adversity, and sociodemographic, socioeconomic, psychosocial, and lifestyle factors. A total of 5087 participants provided repeated information on alcohol consumption. We used marginal structural models to analyze the association between alcohol consumption and depression while controlling for previous alcohol consumption and depressive symptoms and other time-varying confounders.

RESULTS

Non-drinkers had a higher depression risk than light drinkers (≤7 drinks/week) (risk ratio: 1.7; 95% confidence interval 1.3-2.1). Consumers of seven-fourteen drinks/week had a depression risk similar to that of light drinkers. Hazardous drinking was associated with a higher risk of depression than non-hazardous alcohol consumption (risk ratio: 1.8, 95% confidence interval: 1.4-2.4).

CONCLUSION

Light and moderate alcohol consumption and non-hazardous drinking were associated with the lowest risk of subsequent depression after accounting for potential bidirectional effects. Hazardous drinking increased the risk of depression.

Evidence of causal effect of major depression on alcohol dependence: findings from the psychiatric genomics consortium

BACKGROUND

Despite established clinical associations among major depression (MD), alcohol dependence (AD), and alcohol consumption (AC), the nature of the causal relationship between them is not completely understood. We leveraged genome-wide data from the Psychiatric Genomics Consortium (PGC) and UK Biobank to test for the presence of shared genetic mechanisms and causal relationships among MD, AD, and AC.

METHODS

Linkage disequilibrium score regression and Mendelian randomization (MR) were performed using genome-wide data from the PGC (MD: 135 458 cases and 344 901 controls; AD: 10 206 cases and 28 480 controls) and UK Biobank (AC-frequency: 438 308 individuals; AC-quantity: 307 098 individuals).

RESULTS

Positive genetic correlation was observed between MD and AD (rgMD-AD = + 0.47, P = 6.6 × 10-10). AC-quantity showed positive genetic correlation with both AD (rgAD-AC quantity = + 0.75, P = 1.8 × 10-14) and MD (rgMD-AC quantity = + 0.14, P = 2.9 × 10-7), while there was negative correlation of AC-frequency with MD (rgMD-AC frequency = -0.17, P = 1.5 × 10-10) and a non-significant result with AD. MR analyses confirmed the presence of pleiotropy among these four traits. However, the MD-AD results reflect a mediated-pleiotropy mechanism (i.e. causal relationship) with an effect of MD on AD (beta = 0.28, P = 1.29 × 10-6). There was no evidence for reverse causation.

CONCLUSION

This study supports a causal role for genetic liability of MD on AD based on genetic datasets including thousands of individuals. Understanding mechanisms underlying MD-AD comorbidity addresses important public health concerns and has the potential to facilitate prevention and intervention efforts.

Mapping risk factors for depression across the lifespan: An umbrella review of evidence from meta-analyses and Mendelian randomization studies

The development of depression may involve a complex interplay of environmental and genetic risk factors. PubMed and PsycInfo databases were searched from inception through August 3, 2017, to identify meta-analyses and Mendelian randomization (MR) studies of environmental risk factors associated with depression. For each eligible meta-analysis, we estimated the summary effect size and its 95% confidence interval (CI) by random-effects modeling, the 95% prediction interval, heterogeneity with I², and evidence of small-study effects and excess significance bias. Seventy meta-analytic reviews met the eligibility criteria and provided 134 meta-analyses for associations from 1283 primary studies. While 109 associations were nominally significant (P < 0.05), only 8 met the criteria for convincing evidence and, when limited to prospective studies, convincing evidence was found in 6 (widowhood, physical abuse during childhood, obesity, having 4-5 metabolic risk factors, sexual dysfunction, job strain). In studies in which depression was assessed through a structured diagnostic interview, only associations with widowhood, job strain, and being a Gulf War veteran were supported by convincing evidence. Additionally, 8 MR studies were included and provided no consistent evidence for the causal effects of obesity, smoking, and alcohol consumption. The proportion of variance explained by genetic risk factors was extremely small (0.1-0.4%), which limited the evidence provided by the MR studies. Our findings suggest that despite the large number of putative risk factors investigated in the literature, few associations were supported by robust evidence. The current findings may have clinical and research implications for the early identification of individuals at risk for depression.

Alcohol Intake and Risk of Ischemic and Haemorrhagic Stroke: Results from a Mendelian Randomisation Study

BACKGROUND AND PURPOSE

To test whether alcohol intake, both observational and estimated by genetic instruments, is associated with risk of ischemic and haemorrhagic stroke.

METHODS

We used data from the Copenhagen City Heart Study 1991 to 1994 and 2001 to 2003, and the Copenhagen General Population Study 2003 to 2012 (n=78,546). As measure of alcohol exposure, self-reported consumption and genetic variation in alcohol metabolizing genes (alcohol dehydrogenase ADH1B and ADH1C) as instrumental variables were used. Stroke diagnoses were obtained from a validated hospital register.

RESULTS

During follow-up 2,535 cases of ischemic and haemorrhagic stroke occurred. Low and moderate alcohol intake (1 to 20 drinks/week) was associated with reduced risk of stroke. The hazard ratios associated with drinking 1 to 6, 7 to 13, and 14 to 20 drinks/week were 0.84 (95% confidence interval [CI], 0.76 to 0.92), 0.83 (95% CI, 0.73 to 0.94), and 0.84 (95% CI, 0.73 to 0.97), respectively, compared with drinking <1 drink/day. ADH1B and ADH1C genotypes were not associated with risk of stroke. Further analysis to test the included measures revealed that increasing alcohol intake (per 1 drink/day) was positively associated with risk of alcoholic liver cirrhosis, but not associated with risk of stroke, and that increasing blood pressure (per systolic 10 mm Hg) was not associated with risk of alcoholic liver cirrhosis, but positively associated with risk of stroke.

CONCLUSIONS

Low and moderate self-reported alcohol intake was associated with reduced risk of stroke. The result was not supported by the result from the causal genetic analysis.

Adaptive and non-adaptive models of depression: A comparison using register data on antidepressant medication during divorce

Divorce is associated with an increased probability of a depressive episode, but the causation of events remains unclear. Adaptive models of depression propose that depression is a social strategy in part, whereas non-adaptive models tend to propose a diathesis-stress mechanism. We compare an adaptive evolutionary model of depression to three alternative non-adaptive models with respect to their ability to explain the temporal pattern of depression around the time of divorce. Register-based data (304,112 individuals drawn from a random sample of 11% of Finnish people) on antidepressant purchases is used as a proxy for depression. This proxy affords an unprecedented temporal resolution (a 3-monthly prevalence estimates over 10 years) without any bias from non-compliance, and it can be linked with underlying episodes via a statistical model. The evolutionary-adaptation model (all time periods with risk of divorce are depressogenic) was the best quantitative description of the data. The non-adaptive stress-relief model (period before divorce is depressogenic and period afterwards is not) provided the second best quantitative description of the data. The peak-stress model (periods before and after divorce can be depressogenic) fit the data less well, and the stress-induction model (period following divorce is depressogenic and the preceding period is not) did not fit the data at all. The evolutionary model was the most detailed mechanistic description of the divorce-depression link among the models, and the best fit in terms of predicted curvature; thus, it offers most rigorous hypotheses for further study. The stress-relief model also fit very well and was the best model in a sensitivity analysis, encouraging development of more mechanistic models for that hypothesis.

High alcohol consumption causes high IgE levels but not high risk of allergic disease

BACKGROUND

High alcohol consumption is associated with high IgE levels in observational studies; however, whether high alcohol consumption leads to high IgE levels and allergic disease is unclear.

OBJECTIVE

We tested the hypothesis that high alcohol consumption is associated with high IgE levels and allergic disease both observationally and genetically using a Mendelian randomization design free of reverse causation and largely free of confounding.

METHODS

Among 111,408 subjects aged 20 to 100 years from the general population, 50,019 had plasma IgE measurements, and 102,270 were genotyped for the alcohol-metabolizing enzymes alcohol dehydrogenase 1B (ADH-1B; rs1229984) and alcohol dehydrogenase 1c (ADH-1C; rs698). Observationally, we investigated associations between IgE levels and allergic disease (allergic asthma, rhinitis, and eczema) and between alcohol consumption and IgE levels and allergic disease. Genetically, we explored potential causal relationships between alcohol consumption and IgE levels and allergic disease.

RESULTS

The multivariable adjusted odds ratio for IgE levels greater than versus less than 150 kU/L and compared with subjects without allergic disease was 2.3 (95% CI, 2.2-2.5) for 1 allergic disease, 3.9 (95% CI, 3.5-4.4) for 2 allergic diseases, and 7.5 (95% CI, 6.2-9.0) for 3 allergic diseases. High alcohol consumption was associated with high IgE levels but not with high risk of allergic disease. The odds ratio for high versus low IgE levels per 1 alcoholic drink per week higher consumption was 1.12 (95% CI, 1.02-1.23) genetically and 1.01 (95% CI, 1.01-1.02) observationally; for allergic disease, the corresponding odds ratios were 0.96 (95% CI, 0.92-1.00) genetically and 1.00 (95% CI, 1.00-1.00) observationally.

CONCLUSION

High alcohol consumption is associated observationally and genetically with high IgE levels but not with high risk of allergic disease.