Background: A growing number of studies suggest that maternal stress during pregnancy promotes atopic disorders in the offspring. This is the first systematic review to address prenatal maternal stress (PNMS) and the subsequent risk of atopy‐related outcomes in the child.Methods: The review was performed in accordance to the PRISMA criteria. We searched and selected studies in PubMed, Scopus, Embase and PsychINFO until November 2014.Results: Sixteen (with 25 analyses) of 426 identified articles met the review criteria. Five main PNMS exposures (negative life events, anxiety/depression, bereavement, distress and job strain) and five main atopic outcomes (asthma, wheeze, atopic dermatitis, allergic rhinitis and IgE) were assessed across the studies. Overall, 21 of the 25 analyses suggested a positive association between PNMS and atopic outcomes. Of the 11 exposure–response analyses reported, six found statistically significant trends.Conclusion: This systematic review suggests a relationship between maternal stress during pregnancy and atopic disorders in the child. However, the existing studies are of diverse quality. The wide definitions of often self‐reported stress exposures imply a substantial risk for information bias and false‐positive results. Research comparing objective and subjective measures of PNMS exposure as well as objective measures for atopic outcome is needed.

Background: Preliminary research suggests an association between depression and subsequent increased risk of infections, yet little is known on this topic. This study investigated the association between depression and risk of various types of infections, including temporal and dose-response relationships.

Background.: Autoimmune diseases are associated with substantial morbidity and mortality, yet the etiology remains unclear. Depression has been implicated as a risk factor for various immune-related disorders but little is known about the risk of autoimmune disease. This study examined the association between depression and the risk of autoimmune disease, and investigated the temporal and dose-response nature of these relationships.Method.: A prospective population-based study including approximately 1.1 million people was conducted using linked Danish registries. Depression and autoimmune diseases were diagnosed by physicians and documented in medical records. In total, 145 217 individuals with depression were identified between 1995 and 2012. Survival analyses were used to estimate the relative risk of autoimmune disease among those with, compared to without, depression. Analyses were adjusted for gender, age, and co-morbid mental disorders.Results.: Depression was associated with a significantly increased risk of autoimmune disease [incidence rate ratio (IRR) 1.25, 95% CI 1.19–1.31], compared to those without a history of depression. Results suggest a general increased risk of autoimmune diseases following the onset of depression during first year (IRR 1.29, 95% CI 1.05–1.58), which remained elevated for the ensuing 11 years and beyond (IRR 1.53, 95% CI 1.34–1.76). Findings did not support a dose-response relationship.Conclusions.: Depression appears to be associated with an increased risk of a range of autoimmune diseases. Depression may play a role in the etiology of certain autoimmune conditions. If replicated, findings could highlight additional clinical implications in the treatment and management of depression. Future studies are needed to investigate the possible social, genetic, and neurobiological underpinnings of these relationships.

Aims.: Literature suggests an association between loneliness and mortality for both males and females. Yet, the linkage of loneliness to mortality is not thoroughly examined, and need to be replicated with a long follow-up time. This study assessed the association between loneliness and mortality, including associations to gender, in 1363 adult swedes.Methods.: This community-based prospective cohort study from the Swedish Lundby Study included 1363 individuals of whom 296 individuals (21.7%) were identified as lonely with use of semi-structured interviews in 1997. The cohort was followed until 2011 and survival analyses were used to estimate the relative risk of death.Results.: Death occurred with an incidence rate of 2.63 per 100 person-years and 2.09 per 100 person-years for lonely and non-lonely individuals, respectively. In crude analysis, loneliness was associated with a significant increased mortality risk of 27% compared with non-lonely individuals [hazard ratio (HR) 1.27; 95% CI 1.01–1.60]. Unadjusted, lonely females had a significant increased risk (HR 1.76; 95% CI 1.31–2.34) and adjusted insignificant increased mortality risk of 27% (HR 1.27; 95% CI 0.92–1.74), compared with non-lonely females. Lonely males were found to have an adjusted significant decreased risk of mortality (HR 0.50; 95% CI 0.32–0.80), compared with non-lonely males.Conclusions.: Findings suggest an association between loneliness and increased risk of mortality and that gender differences may exist, which have not been previously reported. If replicated, our results indicate that loneliness may have differential physical implications in some subgroups. Future studies are needed to further investigate the influence of gender on the relationship.

Objective: To estimate the effectiveness of the bivalent mRNA booster vaccines containing the original SARS-CoV-2 and omicron BA.4-5 or BA.1 subvariants as the fourth dose against severe covid-19. Design: Nationwide cohort analyses, using target trial emulation. Setting: Denmark, Finland, Norway, and Sweden, from 1 July 2022 to 10 April 2023. Participants: People aged ≥50 years who had received at least three doses of covid-19 vaccine (that is, a primary course and a first booster). Main outcome measures: The Kaplan-Meier estimator was used to compare the risk of hospital admission and death related to covid-19 in people who received a bivalent Comirnaty (Pfizer-BioNTech) or Spikevax (Moderna) BA.4-5 or BA.1 mRNA booster vaccine as a fourth dose (second booster) with three dose (first booster) vaccinated people and between four dose vaccinated people. Results: A total of 1 634 199 people receiving bivalent BA.4-5 fourth dose booster and 1 042 124 receiving bivalent BA.1 fourth dose booster across the four Nordic countries were included. Receipt of a bivalent BA.4-5 booster as a fourth dose was associated with a comparative vaccine effectiveness against admission to hospital with covid-19 of 67.8% (95% confidence interval 63.1% to 72.5%) and a risk difference of –91.9 (95% confidence interval –152.4 to –31.4) per 100 000 people at three months of follow-up compared with having received three doses of vaccine (289 v 893 events). The corresponding comparative vaccine effectiveness and risk difference for bivalent BA.1 boosters (332 v 977 events) were 65.8% (59.1% to 72.4%) and –112.9 (–179.6 to –46.2) per 100 000, respectively. Comparative vaccine effectiveness and risk difference against covid-19 related death were 69.8% (52.8% to 86.8%) and –34.1 (–40.1 to –28.2) per 100 000 for bivalent BA.4-5 booster (93 v 325 events) and 70.0% (50.3% to 89.7%) and –38.7 (–65.4 to –12.0) per 100 000 for BA.1 booster (86 v 286) as a fourth dose. Comparing bivalent BA.4-5 and BA.1 boosters as a fourth dose directly resulted in a three month comparative vaccine effectiveness and corresponding risk difference of –14.9% (–62.3% to 32.4%) and 10.0 (–14.4 to 34.4) per 100 000 people for admission to hospital with covid-19 (802 v 932 unweighted events) and –40.7% (–123.4% to 42.1%) and 8.1 (–3.3 to 19.4) per 100 000 for covid-19 related death (229 v 243 unweighted events). The comparative vaccine effectiveness did not differ across sex and age (</≥70 years) and seemed to be sustained up to six months from the day of vaccination with modest waning. Conclusion: Vaccination with bivalent BA.4-5 or BA.1 mRNA booster vaccines as a fourth dose was associated with reduced rates of covid-19 related hospital admission and death among adults aged ≥50 years. The protection afforded by the bivalent BA.4-5 and BA.1 boosters did not differ significantly when directly compared, and any potential difference would most likely be very small in absolute numbers.