Staying connected: An umbrella review of meta-analyses on the push-and-pull of social connection in depression.

BACKGROUND: Depression affects approximately 4 % of the global population and has huge social and economic implications. Social factors, including support, engagement, and stigma, play a crucial role in the development and severity of depression. METHODS: We provide a synthesis of the consistency and magnitude of the association between measures of social connection and depression. We searched PubMed, PsycINFO, Cochrane Library, and EMBASE and 47 meta-analyses were included in the umbrella review. The strength of the associations was extracted and compared among different populations. The quality/certainty of evidence was assessed using AMSTAR-2 and GRADE tool. RESULTS: Results indicate that social support serves as a protective factor against depression, particularly in peripartum populations, while its impact is weaker in clinical populations. No association was found between social support and depression in post-disaster populations. Stigma and discrimination favour the development and maintenance of depressive symptoms in clinical populations, but have a weaker effect in ethnic minorities. LIMITATIONS: The quality and certainty of evidence should be taken into account when interpreting our findings. Further research with more rigorous methodology and higher-quality evidence is needed to better understand the complex relationship between depression and social connection across various populations and contexts. CONCLUSIONS: Our findings confirm the role of social determinants in the emergence and severity of depression, particularly in the case of vulnerable populations. Efforts to counteract disconnection at the societal and individual levels and to reduce stigma should be central to an effective depression prevention agenda.

Bdnf-Nrf-2 crosstalk and emotional behavior are disrupted in a sex-dependent fashion in adolescent mice exposed to maternal stress or maternal obesity.

Maternal obesity has been recognized as a stressor affecting the developing fetal brain, leading to long-term negative outcomes comparable to those resulting from maternal psychological stress, although the mechanisms have not been completely elucidated. In this study, we tested the hypothesis that adverse prenatal conditions as diverse as maternal stress and maternal obesity might affect emotional regulation and stress response in the offspring through common pathways, with a main focus on oxidative stress and neuroplasticity. We contrasted and compared adolescent male and female offspring in two mouse models of maternal psychophysical stress (restraint during pregnancy - PNS) and maternal obesity (high-fat diet before and during gestation - mHFD) by combining behavioral assays, evaluation of the hypothalamic-pituitary-adrenal (HPA) axis reactivity, immunohistochemistry and gene expression analysis of selected markers of neuronal function and neuroinflammation in the hippocampus, a key region involved in stress appraisal. Prenatal administration of the antioxidant N-acetyl-cysteine (NAC) was used as a strategy to protect fetal neurodevelopment from the negative effects of PNS and mHFD. Our findings show that these two stressors produce overlapping effects, reducing brain anti-oxidant defenses (Nrf-2) and leading to sex-dependent impairments of hippocampal Bdnf expression and alterations of the emotional behavior and HPA axis functionality. Prenatal NAC administration, by restoring the redox balance, was able to exert long-term protective effects on brain development, suggesting that the modulation of redox pathways might be an effective strategy to target common shared mechanisms between different adverse prenatal conditions.