Chronic dysregulation of peripheral lipids has been found to be associated with depression and cognition, but their interaction has not been investigated. Growing evidence has highlighted the association between peripheral lipoprotein levels with depression and cognition with inconsistent results. We assessed the association between peripheral lipids, depression, and cognition while evaluating their potential interactions using robust clinically relevant predictors such as lipoprotein levels and chronic medical disorders that dysregulate lipoproteins. We report an association between peripheral lipids, depression, and cognition, suggesting a common underlying biological mechanism driven by lipid dysregulation in two independent studies. Analysis of a longitudinal study of a cohort at high or low familial risk for major depressive disorder (MDD) (n = 526) found metabolic diseases, including diabetes, hypertension, and other cardiovascular diseases, were associated with MDD and cognitive outcomes. Investigating a cross-sectional population survey of adults in the National Health and Nutrition Examination Survey 2011–2014 (NHANES) (n = 2377), depression was found to be associated with high density lipoprotein (HDL) and cognitive assessments. In the familial risk study, medical conditions were found to be associated with chronic lipid dysregulation and were significantly associated with MDD using the structural equation model. A positive association between chronic lipid dysregulation and cognitive scores was found in an exploratory analysis of the familial risk study. In a complementary study, analysis of NHANES revealed a positive association of HDL levels with cognition. Further analysis of the NHANES cohort indicated that depression status mediated the interaction between HDL levels and cognitive tests. Importantly, the protective effect of HDL on cognition was absent in those with depressive symptoms, which may ultimately result in worse outcomes leading to cognitive decline. These findings highlight the potential for the early predictive value of medical conditions with chronic lipid dyshomeostasis for the risk of depression and cognitive decline.

Several studies have shown protective effects between health outcomes and subjective reports of religious/spiritual (R/S) importance, as measured by a single self-report item. In a 3-generation study of individuals at high or low familial risk for depression, R/S importance was found to be protective against depression, as indicated by clinical and neurobiological outcomes. The psychological components underlying these protective effects, however, remain little understood. Hence, to clarify the meaning of answering the R/S importance item, we employed a comprehensive set of validated scales assessing religious beliefs and experiences and exploratory factor analysis to uncover latent R/S constructs that strongly and independently correlated with the single-item measure of R/S importance. A Varimax-rotated principal component analysis (PCA) resulted in a 23-factor solution (Eigenvalue > 1; 71.5% explained variance) with 8 factors that, respectively, accounted for at least 3% of the total variance. The first factor (15.8%) was directly related to the R/S importance item (r = .819), as well as personal relationship with the Divine, forgiveness by God, religious activities, and religious coping, while precluding gratitude, altruism, and social support, among other survey subscales. The corresponding factor scores were greater in older individuals and those at low familial risk. Moreover, Spearman rank-order correlations between the R/S importance item and other subscales revealed relative consistency across generations and risk groups. Taken together, the single R/S importance item constituted a robust measure of what may be generally conceived of as “religious importance,” ranking highest among a diverse latent factor structure of R/S. As this suggests adequate single-item construct validity, it may be adequate for use in health studies lacking the resources for more extensive measures. Nonetheless, given that this single item accounted for only a small fraction of the total survey variance, results based on the item should be interpreted and applied with caution.

The personal importance of religion or spirituality (R/S) has been associated with a lower risk for major depression (MDD), suicidal behavior, reduced cortical thinning and increased posterior EEG alpha, which has also been linked to antidepressant treatment response in MDD. Building on prior event-related potential (ERP) findings using an emotional hemifield paradigm, this study examined whether abnormal early (preconscious) responsivity to negative arousing stimuli, which is indicative of right parietotemporal dysfunction in both MDD patients and individuals at clinical high risk for MDD, is likewise moderated by R/S. We reanalyzed 72-channel ERP data from 127 individuals at high or low family risk for MDD (Kayser et al. 2017 NeuroImage Clin 14:692-707) after R/S stratification (low R/S importance, low/high risk, n = 38/61; high R/S importance, n = 15/13). ERPs were transformed to reference-free current source density (CSD) and quantified by temporal principal components analysis (tPCA). This report focused on N2 sink (peak latency 212 ms), the earliest prominent CSD-tPCA component previously found to be sensitive to emotional content. While overall N2 sink reflected activation of occipitotemporal cortex (prestriate/cuneus), as estimated via a distributed inverse solution, affective significance was marked by a relative (i.e., superimposed) positivity. Statistical analyses employed both nonparametric permutation tests and repeated measures ANOVA for mixed factorial designs with unstructured covariance matrix, including sex, age and clinical covariates. Participants with low R/S importance, independent of risk status, showed greater ERP responsivity to negative than neutral stimuli, particularly over the right hemisphere. In contrast, early emotional ERP responsivity and asymmetry was substantially reduced for high risk individuals with high R/S importance, however, enhanced for low risk individuals with high R/S importance. Hemifield modulations of these effects (i.e., emotional ERP enhancements with left visual field/right hemisphere stimulus presentations) further corroborated these observations. Results suggest down-regulation of a right-lateralized network for salience detection at an early processing stage in high risk and high R/S importance individuals, presumably to prevent overactivation of ventral brain regions further downstream. These findings may point to a neurophysiological mechanism underlying resilience of families at risk for depression with high R/S prioritization.