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Objectives: To evaluate temporal dynamics between loneliness and both objective and subjective health (i.e., functional impairment and self-rated health) in mid- to late-adulthood. Method: We applied Bivariate Dual-Change-Score Models to longitudinal data from 3 Swedish twin studies (N = 1,939) to explore dynamic associations between loneliness and health across 3 age ranges (50-70, 70-82, and >82 years) to investigate whether associations between loneliness and health change with age due to increasing incidence of chronic health conditions and bereavement.Results: Results showed bidirectional associations between loneliness and both objective and subjective health, with adverse impacts of loneliness observed on subsequent subjective and objective health beginning at age 70. Associations between health and subsequent loneliness were observed after age 82 and varied for subjective and objective health, with subjective health associated with less loneliness and objective health associated with greater loneliness.Conclusions: Our results indicate dynamic associations between loneliness and health with age in mid- to late-adulthood, with earlier impacts of loneliness on health and later impacts of health on loneliness that vary for objective and subjective measures of health. These findings suggest impacts of health on loneliness may arise later in life when worsening health or mobility interfere with social interaction.

Importance Parkinson disease (PD) and inflammatory bowel disease (IBD) have been associated, implying shared pathophysiology. Characterizing genetic pleiotropy between the two conditions aids the exploration of common etiology. Objective To estimate the genetic correlation between PD and IBD and to identify specific loci influencing both conditions. Design Genetic study with applications of high definition likelihood and conditional false discovery rate (FDR) framework. Setting The study was based on summary statistics of genome-wide association studies (GWAS). Participants The PD GWAS comprised 37,688 cases and 981,372 controls, and the IBD GWAS included 25,042 cases and 34,915 controls. Participants were of mixed ethnicity. Exposures None. Main Outcomes and Measures The main outcomes were a set of single nucleotide polymorphisms (SNPs) identified by conditional FDR analysis as jointly associated with PD and IBD. Results Weak but statistically significant genetic correlations were detected for PD with both Crohn's disease (CD) and ulcerative colitis (UC), the two main subtypes of IBD. A total of 1333 SNPs in 28 genomic loci and 1915 SNPs in 22 loci were jointly associated with PD-CD and PD-UC, respectively, at conjunctional FDR under 0.01. The pleiotropic loci appeared distinctive for PD-CD and PD-UC, are mostly novel and comprise loci with either same or opposing genetic effects on the two phenotypes. Positional and eQTL mapping prioritized 316 PD-CD and 303 PD-UC genes, among which only

Electroconvulsive therapy (ECT) is the treatment of choice for severe and treatment-resistant\ud depression; disorder severity and unfavorable treatment outcomes are shown to be influenced\ud by an increased genetic burden for major depression (MD). Here, we tested whether ECT assignment\ud and response/nonresponse are associated with an increased genetic burden for major\ud depression (MD) using polygenic risk score (PRS), which summarize the contribution of diseaserelated\ud common risk variants. Fifty-one psychiatric inpatients suffering from a major depressive\ud episode underwent ECT. MD-PRS were calculated for these inpatients and a separate\ud population-based sample (n = 3,547 healthy; n = 426 self-reported depression) based on summary\ud statistics from the Psychiatric Genomics Consortium MDD-working group (Cases:\ud n = 59,851; Controls: n = 113,154). MD-PRS explained a significant proportion of disease status\ud between ECT patients and healthy controls (p = .022, R2 = 1.173%); patients showed higher\ud MD-PRS. MD-PRS in population-based depression self-reporters were intermediate between\ud ECT patients and controls (n.s.). Significant associations between MD-PRS and ECT response\ud (50% reduction in Hamilton depression rating scale scores) were not observed. Our findings indicate\ud that ECT cohorts show an increased genetic burden for MD and are consistent with the\ud hypothesis that treatment-resistant MD patients represent a subgroup with an increased genetic\ud risk for MD. Larger samples are needed to better substantiate these findings.

Given previous findings from animal studies and small-scale studies in humans, variation in the μ-opioid receptor gene (

BackgroundDespite 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.MethodsThis study was conducted using genome-wide data from the Psychiatric Genomics Consortium (MD: 135,458 cases and 344,901 controls; AD: 10,206 cases and 28,480 controls) and UK Biobank (AC-Frequency: from “daily or almost daily” to “never”, 438,308 individuals; AC-Quantity: total units of alcohol per week, 307,098 individuals). Linkage disequilibrium score regression and Mendelian Randomization (MR) analyses were applied to investigate shared genetic mechanisms (horizontal pleiotropy) and causal relationships (mediated pleiotropy) among these traits.OutcomesPositive 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 traits. However, the MD-AD results reflect a mediated-pleiotropy mechanism (i.e., causal relationship) with a causal role of MD on AD (beta=0.28, P=1.29×10-6) that does not appear to be biased by confounding such as horizontal pleiotropy. No evidence of reverse causation was observed as the AD genetic instrument did not show a causal effect on MD.InterpretationResults support a causal role for MD on AD based on genetic datasets including thousands of individuals. Understanding mechanisms underlying MD-AD comorbidity not only addresses important public health concerns but also has the potential to facilitate prevention and intervention efforts.FundingNational Institute of Mental Health and National Institute on Drug Abuse.Putting data into contextEvidence before this studyWe searched PubMed up to August 24, 2018, for research studies that investigated causality among alcohol-and depression related phenotypes using Mendelian randomization approaches. We used the search terms “alcohol” AND “depression” AND “Mendelian Randomization”. No restrictions were applied to language, date, or article type. Ten articles were retrieved, but only two were focused on alcohol consumption and depression-related traits. The studies were based on genetic variants in alcohol dehydrogenase (ADH) genes only, did not find evidence for a causal effect of alcohol consumption on depression phenotypes, with one study finding a causal effect of alcohol consumption on alcoholism. Both studies noted that future studies are needed with increased sample sizes and clinically derived phenotypes. To our knowledge, no previous study has applied two-sample Mendelian randomization to investigate causal relationships between alcohol dependence and major depression.Twin studies show genetic factors influence susceptibility to MD, AD, and alcohol consumption. Differently from observational approaches where several studies have investigated the relationship between alcohol-and depression-related phenotypes, very limited use of molecular genetic data has been applied to investigate this issue. Additionally, the use of genetic information has been shown to be less biased by confounders and reverse causation than observation data. However, genetic approaches, like Mendelian randomization, require large sample sizes to be informative.Added value of this studyIn this study, we used genome-wide data from the Psychiatric Genomic Consortium and UK Biobank, which include information regarding hundred thousands of individuals, to test the presence of shared genetic mechanisms and causal relationships among major depression, alcohol dependence, and alcohol consumption. The results support a causal influence of MD on AD, while alcohol consumption showed shared genetic mechanisms with respect to both major depression and alcohol dependence.Implications of all the available evidenceGiven the significant morbidity and mortality associated with MD, AD, and the comorbid condition, understanding mechanisms underlying these associations not only address important public health concerns but also has the potential to facilitate prevention and intervention efforts.

Results from 2 twin studies of aging differ concerning the heritability of memory performance in adulthood. Heritability estimates from the Minnesota Twin Study of Adult Development and Aging (MTSADA; D. FinkelM. McGue, 1993) are larger than estimates from the Swedish data (N. L. Pedersen, R. Plomin, J. R. Nesselroade,G. E. McClearn, 1992). Memory data were available from MTSADA on a sample of 112 monozygotic (MZ) twin pairs and 111 dizygotic (DZ) twin pairs ages 27 to 88 years and from the Swedish study on a sample of 86 MZ and 110 DZ twin pairs who were reared together and were ages 27 to 85 years. Univariate and multivariate behavior genetic analyses were conducted to determine the significance and source of differences in heritability across studies. No significant age differences were found in either study. Study differences were found at the level of specific memory measures, but not at the level of a general memory factor.

The influence of genetic factors for two personality dimensions was analyzed using data from 12,898 unselected twin pairs of the Swedish Twin Registry. The heritability index was 0.50 (men) and 0.58 (women) for psychosocial instability. Corresponding figures for psychosocial extraversion were 0.54 and 0.66. Thus, about half the phenotypic variation may be attributed to genetic factors.