Time-lagged associations between two adverse childhood experiences and later-life cognitive function through educational attainment and stroke.

OBJECTIVE: Adverse childhood experiences (ACEs) have been associated with worse cognitive health in older adulthood. This study aimed to extend findings on the specificity, persistence, and pathways of associations between two ACEs and cognition by using a comprehensive neuropsychological battery and a time-lagged mediation design. METHOD: Participants were 3304 older adults in the Health and Retirement Study Harmonized Cognitive Assessment Protocol. Participants retrospectively reported whether they were exposed to parental substance abuse or experienced parental physical abuse before age 18. Factor scores derived from a battery of 13 neuropsychological tests indexed cognitive domains of episodic memory, executive functioning, processing speed, language, and visuospatial function. Structural equation models examined self-reported years of education and stroke as mediators, controlling for sociodemographics and childhood socioeconomic status. RESULTS: Parental substance abuse in childhood was associated with worse later-life cognitive function across all domains, in part via pathways involving educational attainment and stroke. Parental physical abuse was associated with worse cognitive outcomes via stroke independent of education. CONCLUSIONS: This national longitudinal study in the United States provides evidence for broad and persistent indirect associations between two ACEs and cognitive aging via differential pathways involving educational attainment and stroke. Future research should examine additional ACEs and mechanisms as well as moderators of these associations to better understand points of intervention.

Specific aspects of religious involvement protect against depressive symptoms among immigrant versus U.S.-born, Hispanic older adults.

OBJECTIVES: This study investigates religious involvement and depressive symptoms in Hispanic older adults in the United States. We hypothesized that private prayer, religious attendance, and religious belief would have an inverse association with depressive symptoms, and that these associations would be stronger among immigrants, compared to U.S.-born participants. METHOD: This cross-sectional, within-group study included 1,566 participants from the Health and Retirement Study. Multivariate linear regression evaluated the association between religious involvement and depressive symptoms in the whole sample and in subgroups stratified by immigrant status. RESULTS: Overall, only more frequent religious attendance was associated with fewer depressive symptoms. Stratified models revealed an additional inverse association between private prayer and depressive symptoms only in the immigrant group. CONCLUSION: These findings may help incorporate religious preferences into mental health prevention and treatment to reduce depressive symptoms among older Hispanic adults.

Riding the merry-go-round of racial disparities in ADRD research.

INTRODUCTION: With the rapid expansion of the aging population, the burden of Alzheimer's disease related dementias (ADRD) is anticipated to increase in racialized and minoritized groups who are at disproportionately higher risk. To date, research emphasis has been on further characterizing the existence of racial disparities in ADRD through comparisons to groups racialized as White that are assumed to be normative. Much of the literature on this comparison insinuates that racialized and minoritized groups experience poorer outcomes due to genetics, culture, and/or health behaviors. METHODS: This perspective shines a light on a category of ADRD research that employs ahistorical methodological approaches to describe racial disparities in ADRD that puts us on a merry-go-round of research with no benefits to society. METHODS: This commentary provides historical context for the use of race in ADRD research and justification for the study of structural racism. The commentary concludes with recommendations to guide future research.

Depressive Symptoms Longitudinally Mediate the Effect of Hyperglycemia on Memory Decline in Type 2 Diabetes.

OBJECTIVE: We sought to examine the mediating role of changes in depressive symptoms in the association between chronic hyperglycemia and longitudinal cognition in a sample of older adults with type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS: We conducted a longitudinal mediation analysis using structural equation modeling of observational data collected over 6 years from 2,155 participants with T2D (aged ≥51 years) in the U.S.-wide Health and Retirement Study. T2D was defined using self-reported diagnosis, and HbA1c was assessed at study baseline. Self-reported depressive symptoms were assessed at two time points 4 years apart. Episodic memory was measured using a list-learning test administered at three time points over 6 years. We adjusted for sociodemographics, chronic health comorbidities, medication adherence, study enrollment year, and prior years' depressive symptoms and memory scores. RESULTS: At baseline, participants' mean age was 69.4 (SD = 9.1), mean HbA1c was 7.2% (SD = 1.4%), 55.0% were women, 19.3% were non-Latinx Black, and 14.0% were Latinx. Higher baseline levels of HbA1c were associated with increases in depressive symptoms over 4 years, which, in turn, were associated with poorer memory 2 years later. Depressive symptoms accounted for 19% of the longitudinal effect of HbA1c on memory over the 6-year period. Sensitivity analyses ruled out alternative directions of associations. CONCLUSIONS: Incident elevations in depressive symptoms mediated the longitudinal association between hyperglycemia and 6-year episodic memory scores. For older adults with T2D, interventions to prevent HbA1c-related incident depressive symptoms may be beneficial in reducing the neurotoxic effects of chronic hyperglycemia on cognition.

Longitudinal associations between racial discrimination and hippocampal and white matter hyperintensity volumes among older Black adults.

RATIONALE: Non-Hispanic Black older adults are at higher risk of Alzheimer's disease and related dementias (ADRD) than non-Hispanic Whites, which reflects racial disparities in both brain and cognitive health. Discrimination may contribute to these disparities, but much of the research on discrimination and ADRD outcomes is cross-sectional and/or does not disaggregate experiences of discrimination by attribution. Focusing specifically on racial discrimination and considering longitudinal brain outcomes may advance our understanding of the role of discrimination in explaining disproportionate rates of ADRD among non-Hispanic Black older adults. METHODS: In total, 221 non-Hispanic Black participants in the Washington Heights-Inwood Columbia Aging Project completed multiple measures of discrimination at one time point and structural magnetic resonance imaging (MRI) scans at two time points. Everyday discrimination and lifetime discrimination were operationalized first as aggregate experiences of discrimination (regardless of identity attributions) and then as racial discrimination per se. MRI outcomes included hippocampal and white matter hyperintensity (WMH) volumes. Latent difference score models estimated associations between the discrimination measures and each MRI outcome over four years. RESULTS: Aggregate discrimination (regardless of attributions) was not associated with either outcome. Lifetime racial discrimination was associated with lower initial hippocampal volume. Everyday racial discrimination was associated with faster accumulation of WMH over time. CONCLUSIONS: Racial discrimination may be detrimental for brain aging among non-Hispanic Black older adults, which may contribute to their disproportionate dementia burden. Disaggregating discrimination by attribution may clarify research on racial inequalities in brain and cognitive aging, as racial discrimination appears to be particularly toxic.

Social engagement and its links to cognition differ across non-Hispanic Black and White older adults.

OBJECTIVE: Racial inequalities in dementia have been linked to disparities in socioeconomic status, chronic diseases, and psychosocial stress. Less focus has been given to psychosocial protective factors. Previous studies suggest that social engagement promotes better cognitive aging, but few have examined whether social engagement or its associations with cognition vary across non-Hispanic Whites (NHW) and Blacks (NHB). METHOD: Participants included 465 adults (53% NHB) from the Michigan Cognitive Aging Project (Mage = 63.59 ± 3.15) who completed a comprehensive neuropsychological battery. Social engagement was operationalized as network size, frequency of social activity participation, and social support. Cognition was operationalized using factor scores corresponding to five domains: episodic memory, executive functioning, processing speed, language, and visuospatial functioning. Cross-sectional associations between social engagement and cognitive outcomes were examined using race-stratified regressions controlling for age, sex/gender, education, wealth, marital status, depressive symptoms, and chronic diseases. RESULTS: There were no racial differences in social network size or social support. NHB participants reported less social activity participation than NHW participants. Social activity participation was positively associated with memory in NHW, but not NHB. CONCLUSIONS: These findings may suggest a threshold effect whereby NHB older adults are less likely to participate in social activities at the level needed to yield cognitive benefits. Lower social activity participation among NHB may reflect structural barriers and/or cultural differences in patterns of social engagement. This study highlights the need to improve measurement of and access to culturally relevant social activities for NHB to combat racial inequalities in cognitive aging. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Genetic and Metabolite Variability in One-Carbon Metabolism Applied to an Insulin Resistance Model in Patients With Schizophrenia Receiving Atypical Antipsychotics.

Background: Patients with schizophrenia are at high risk of pre-mature mortality due to cardiovascular disease (CVD). Our group has completed studies in pharmacogenomics and metabolomics that have independently identified perturbations in one-carbon metabolism as associated with risk factors for CVD in this patient population. Therefore, this study aimed to use genetic and metabolomic data to determine the relationship between folate pharmacogenomics, one-carbon metabolites, and insulin resistance as measured using the homeostatic model assessment for insulin resistance (HOMA-IR) as a marker of CVD. Methods: Participants in this pilot analysis were on a stable atypical antipsychotic regimen for at least 6 months, with no diabetes diagnosis or use of antidiabetic medications. Participant samples were genotyped for MTHFR variants rs1801131 (MTHFR A1298C) and rs1801133 (MTHFR C677T). Serum metabolite concentrations were obtained with NMR. A least squares regression model was used to predict log(HOMA-IR) values based on the following independent variables: serum glutamate, glycine, betaine, serine, and threonine concentrations, and carrier status of the variant alleles for the selected genotypes. Results: A total of 67 participants were included, with a median age of 47 years old (IQR 42-52), 39% were female, and the median BMI was 30.3 (IQR 26.3-37.1). Overall, the model demonstrated an ability to predict log(HOMA-IR) values with an adjusted R 2 of 0.44 and a p-value of < 0.001. Glutamate, threonine, and carrier status of the MTHFR 1298 C or MTHFR 677 T allele were positively correlated with log(HOMA-IR), whereas glycine, serine, and betaine concentrations trended inversely with log(HOMA-IR). All factors included in this final model were considered as having a possible effect on predicting log(HOMA-IR) as measured with a p-value < 0.1. Conclusions: Presence of pharmacogenomic variants that decrease the functional capacity of the MTHFR enzyme are associated with increased risk for cardiovascular disease, as measured in this instance by log(HOMA-IR). Furthermore, serine, glycine, and betaine concentrations trended inversely with HOMA-IR, suggesting that increased presence of methyl-donating groups is associated with lower measures of insulin resistance. Ultimately, these results will need to be replicated in a significantly larger population.

Associations between life course marital biography and late-life memory decline.

Late-life marital status is associated with cognitive aging; however, the influence of life course marital biography (i.e., changes in marital status) on late-life cognitive trajectories, as well as gender differences in the effects of marital biography, remain to be explored. Associations between (a) marital status at study baseline (currently married, previously married, never married) and (b) retrospectively reported life course marital biography (i.e., age at first marriage, time spent unmarried following initial marriage, history of divorce, history of widowhood) and up to 20 years of subsequent episodic memory trajectories were examined using latent growth curve models in 3,061 participants aged 51 + in the Health and Retirement Study 2017 Life History Mail Survey. Gender differences were examined with multiplicative interaction terms and stratified models. Participants who were married at study baseline demonstrated higher initial memory than previously and never married individuals. Older age at first marriage and shorter duration spent unmarried were each associated with better initial episodic memory among previously married individuals only; longer duration spent unmarried was associated with slower memory decline. Stratified models suggested that these associations may be driven by women. These results highlight the importance of considering multiple aspects of marital biography, not just current marital status, in cognitive aging research. Marital biography may have an enduring influence on cognitive aging, particularly among previously married older women. Future work is needed to identify mechanisms (e.g., socioeconomic resources, cognitive stimulation, self and spousal health, emotional support) through which marital histories influence cognitive aging. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Socioeconomic and psychosocial mechanisms underlying racial/ethnic disparities in cognition among older adults.

Objective: Racial/ethnic disparities in cognitive aging are only partly attributable to socioeconomic indicators. Psychosocial factors, such as discrimination and perceived control, also differ across racial/ethnic groups, and emerging literature highlights their potential role in contributing to cognitive disparities in addition to socioeconomic status. Method: 1,463 older adults (51% Hispanic, 27% non-Hispanic Black, and 22% non-Hispanic White) in the Washington Heights-Inwood Columbia Aging Project completed cognitive and psychosocial measures, including a comprehensive neuropsychological battery, Everyday and Major Experiences of Lifetime Discrimination scales, and the Perceived Control scale. Mediation models quantified separate indirect effects of Black race and Hispanic ethnicity on global cognitive composite scores through education, income, discrimination, and external perceived control. Results: Educational attainment, income, and perceived control each mediated racial/ethnic disparities in global cognition. Socioeconomic indicators (i.e., lower education and lower income) explained approximately 50% of the Black-White and Hispanic-White disparities in global cognition, and more external perceived control explained an additional 5%-8%. Hispanics reported the lowest levels of discrimination, while non-Hispanic Blacks reported the highest levels. However, neither everyday nor major lifetime discrimination was associated with global cognition. Significant racial/ethnic disparities in global cognition remained after accounting for the included socioeconomic and psychosocial factors. Conclusions: This study suggests that psychosocial factors may explain racial/ethnic disparities in cognitive aging above and beyond socioeconomic indicators. More external perceived control, which could reflect chronic exposure to interpersonal and institutional marginalization, may be a particularly salient psychosocial risk factor for poorer cognitive aging among non-Hispanic Black and Hispanic older adults. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Subjective age, depressive symptoms, and cognitive functioning across five domains.

Objective: Younger subjective age predicts better episodic memory and executive functioning performance independent of chronological age. This study examined whether subjective age is associated with performance in five cognitive domains, quantified the extent to which these relationships are mediated by depressive symptoms, and tested whether these associations are moderated by chronological age.Method: Participants in this cross-sectional study included 993 adults aged 65 and older from the Health and Retirement Study's 2016 Harmonized Cognitive Assessment Protocol. Moderated mediation models estimated direct and indirect effects of subjective age on factor scores representing episodic memory, executive functioning, language, visuoconstruction, and speed through depressive symptoms and tested whether associations differed according to chronological age.Results: Depressive symptoms explained 21-32% of the associations between subjective age and language, speed, episodic memory, and executive functioning. Chronological age moderated the indirect effect involving language, such that depressive symptoms were more strongly related to worse language performance at older chronological ages. After accounting for indirect effects, direct effects of younger subjective age remained for language and speed domains.Conclusions: This study extends research on the cognitive correlates of subjective age and demonstrates that depressive symptoms partly mediate these relationships. Subjective age may bemost strongly associated with language among individuals at older chronological ages not because they are more sensitive to the negative mental health impact of feeling older than they are but because they may be particularly vulnerable to the negative effects of depressive symptoms on language ability. Additional longitudinal research is needed to determine whether links between subjective age and cognition are causal versus predictive.

Measurement Invariance of Social Media Use in Younger and Older Adults and Links to Socioemotional Health.

BACKGROUND AND OBJECTIVES: Social media use has been linked to socioemotional health; however, less is known regarding whether these associations are moderated by age. Additionally, as the use of social media in older adult populations is rapidly increasing, there is a greater need for the investigation of psychometric properties of social media usage scales before determining age differences in the impact of social media on socioemotional health outcomes. RESEARCH DESIGN AND METHODS: Using an online adult life-span sample (n = 592), the current cross-sectional study tested the measurement invariance of the general social media usage subscale of the Media and Technology Usage and Attitudes Scale across younger (aged 19-54) versus older (aged 55-81) adults and whether age moderated associations between social media use and socioemotional health (depressive symptoms, self-esteem, and envy). RESULTS: Confirmatory factor analyses revealed that posting-related and checking-related items were noninvariant across age groups. In multigroup structural equation models accounting for differential item functioning, higher social media use was associated with more depressive symptoms in younger adults, but not in older adults. While higher social media use was associated with higher envy in both age groups, this association was stronger in younger adults. DISCUSSION AND IMPLICATIONS: Findings suggest younger adults may be more susceptible to the detrimental effects of social media use on socioemotional health. Future directions regarding the measurement of social media use and the salience of social media use across the life span are discussed.

Functional reserve: The residual variance in instrumental activities of daily living not explained by brain structure, cognition, and demographics.

OBJECTIVE: Cognitive reserve is a concept that explains individual differences in resilience to brain pathology and susceptibility to poor late-life cognitive outcomes. We evaluate the analogous concept of "Functional Reserve," defined as the difference between observed functional abilities and those predicted by brain structure, cognitive performance, and demographics. This study aims to validate the construct of functional reserve by testing its utility in predicting clinical outcomes and exploring its predictors. METHOD: Longitudinal data collected annually for up to 7 years from 1,084 older adults (ndementia = 163; nMCI = 333; nCN = 523) were analyzed. Functional reserve was operationalized as the residual variance in the Lawton-Brody Instrumental Activities of Daily Living (IADL) Scale after accounting for demographics (sex/gender, race, ethnicity, education), neuropathology (gray matter, hippocampal, and white matter hyperintensity volumes), and cognition (executive function, verbal episodic memory, semantic memory, and spatial function). Structural equation models estimated (a) functional reserve's associations with 7-year changes in clinical diagnosis and disease severity and (b) predictors of functional reserve. RESULTS: Functional reserve was lower in dementia versus cognitively normal individuals. Higher baseline functional reserve was associated with lower concurrent dementia severity and slower clinical progression and attenuated the association of cognition with concurrent dementia severity. Physical function and apathy were the strongest predictors of functional reserve. CONCLUSIONS: Results provide preliminary validation of functional reserve for explaining individual differences in susceptibility to IADL dysfunction independent of neuropathology, cognition, and demographics. Physical functioning and apathy are promising modifiable intervention targets to enhance functional reserve in the context of brain atrophy and cognitive decline. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Physical Activity in Early- and Mid-Adulthood Are Independently Associated With Longitudinal Memory Trajectories in Later Life.

BACKGROUND: Physical activity (PA) in later life may reduce dementia risk, but little is known regarding long-term cognitive effects of PA that occurred earlier in adulthood or mechanisms underlying associations. PA patterns at different ages may independently contribute to dementia risk, which would implicate multiple critical periods for intervention. The current study tested whether retrospective reports of PA in early and mid-adulthood were independently associated with later-life longitudinal memory outcomes and whether associations were mediated by late-life cardiometabolic diseases. METHOD: Participants comprised 5200 Health and Retirement Study Life History Mail Survey respondents. Latent growth curves estimated independent associations between retrospectively reported PA in early adulthood (age 18-29) and mid-adulthood (age 40-49) and 16-year episodic memory trajectories. Indirect pathways involving the maintenance of PA from early- to mid-adulthood and the influence of PA on later-life cardiometabolic diseases (hypertension, diabetes, and heart disease) were also estimated. RESULTS: PA in early- and mid-adulthood independently predicted higher initial memory level and slower memory decline in later life, respectively. Early-adulthood PA was indirectly associated with later-life memory level through higher mid-adulthood PA and lower rates of later-life hypertension, as well as with subsequent memory decline through higher mid-adulthood PA. CONCLUSIONS: The current findings highlight the importance of PA throughout adulthood, such that initiating and/or maintaining exercise in early- or mid-adulthood may be protective for later-life cognitive health, and hypertension appears to represent a key mediator of these effects.

Mediators and Moderators of the Association Between Perceived Stress and Episodic Memory in Diverse Older Adults.

OBJECTIVE: Stress is a risk factor for numerous negative health outcomes, including cognitive impairment in late-life. The negative association between stress and cognition may be mediated by depressive symptoms, which separate studies have identified as both a consequence of perceived stress and a risk factor for cognitive decline. Pathways linking perceived stress, depressive symptoms, and cognition may be moderated by sociodemographics and psychosocial resources. The goal of this cross-sectional study was to identify modifying factors and enhance understanding of the mechanisms underlying the stress-cognition association in a racially and ethnically diverse sample of older adults. METHOD: A linear regression estimated the association between perceived stress and episodic memory in 578 older adults (Mage = 74.58) in the Washington Heights-Inwood Columbia Aging Project. Subsequent models tested whether depressive symptoms mediated the stress-memory relationship and whether sociodemographics (gender, race, and ethnicity) or perceived control moderated these pathways. RESULTS: Independent of sociodemographics and chronic diseases, greater perceived stress was associated with worse episodic memory. This relationship was mediated by more depressive symptoms. Higher perceived control buffered the association between stress and depressive symptoms. There was no significant moderation by gender, race, or ethnicity. CONCLUSION: Depressive symptoms may play a role in the negative association between perceived stress and cognition among older adults; however, longitudinal analyses and studies using experimental designs are needed. Perceived control is a modifiable psychological resource that may offset the negative impact of stress.

The longitudinal association between social network composition and episodic memory in older adulthood: the importance of contact frequency with friends.

Objectives: The composition of one's social network has been associated with cognition such that a greater proportion of family is associated with worse cognition compared to a greater proportion of friends. It is not clear whether this association between network composition and cognitive aging is driven by potential negative effects of family interactions or positive effects of friend interactions.Methods: Using the Health and Retirement Study (T1: 2006/2008, T2: 2010/2012, T3: 2012/2014), a longitudinal mediation model was conducted to test the effects of composition on episodic memory and latent change in memory through contact frequency with friends and family.Results: Analyses revealed indirect effects of composition on both T2 memory and latent change in memory through contact frequency with friends. A greater proportion of family in one's network was associated with lower contact frequency with friends and in turn lower memory. Composition was also associated with higher contact frequency with family; however, contact frequency with family was not associated with memory.Conclusions: These findings suggest that spending time with family may not affect episodic memory in older adulthood, but spending time with friends may be beneficial. Potential mechanisms and implications regarding the importance of friendships in later life are discussed.

Everyday discrimination and subsequent cognitive abilities across five domains.

OBJECTIVE: Previous research suggests that everyday discrimination is associated with worse concomitant performance in several cognitive domains, as well as faster subsequent declines in episodic memory. This study aimed to extend knowledge on the specificity, durability, and mechanisms of associations between everyday discrimination and cognition by using a comprehensive neuropsychological battery and a longitudinal mediation design. METHOD: Participants included 3,304 older adults in the Health and Retirement Study Harmonized Cognitive Assessment Protocol. Discrimination was assessed using the Everyday Discrimination Scale. Depressive symptoms were assessed with the 8-item Center for Epidemiological Studies Depression Scale. Vascular diseases were quantified as the self-reported presence of hypertension, diabetes, and heart disease. Confirmatory factor analysis was used to estimate episodic memory, executive functioning, processing speed, language, and visuoconstruction across a battery of 13 neuropsychological tests. Structural equation models controlled for sociodemographics and baseline cognition ascertained 2 to 4 years prior. RESULTS: Discrimination was associated with more depressive symptoms and vascular diseases. Depressive symptoms mediated negative effects of discrimination on subsequent functioning across all 5 cognitive domains. Vascular diseases additionally mediated negative effects of discrimination on processing speed. After accounting for mediators, direct negative effects of discrimination remained for executive functioning and visuoconstruction. CONCLUSIONS: This national longitudinal study in the United States provides evidence for broad and enduring effects of everyday discrimination on cognitive aging, which appear to be partially mediated by mental and physical health. Future research should examine additional mechanisms as well as moderators of these associations to better understand points of intervention. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Longitudinal Associations Between Contact Frequency with Friends and with Family, Activity Engagement, and Cognitive Functioning.

OBJECTIVES: Social engagement may be an important protective resource for cognitive aging. Some evidence suggests that time spent with friends may be more beneficial for cognition than time spent with family. Because maintaining friendships has been demonstrated to require more active maintenance and engagement in shared activities, activity engagement may be one underlying pathway that explains the distinct associations between contact frequency with friends versus family and cognition. METHODS: Using two waves of data from the national survey of Midlife in the United States (n = 3707, Mage = 55.80, 51% female at baseline), we examined longitudinal associations between contact frequency with friends and family, activity engagement (cognitive and physical activities), and cognition (episodic memory and executive functioning) to determine whether activity engagement mediates the relationship between contact frequency and cognition. RESULTS: The longitudinal mediation model revealed that more frequent contact with friends, but not family, was associated with greater concurrent engagement in physical and cognitive activities, which were both associated with better episodic memory and executive functioning. CONCLUSION: These findings suggest that time spent with friends may promote both cognitively and physically stimulating activities that could help to preserve not only these social relationships but also cognitive functioning.

Dietary Glutamic Acid, Obesity, and Depressive Symptoms in Patients With Schizophrenia.

Introduction: Schizophrenia is a lifelong condition associated with several comorbid conditions such as physical illnesses like obesity, as well as co-occurring psychiatric symptoms such as depression. Research regarding susceptibility to some of these comorbidities has primary focused on genetic risks or neurotransmitters and very little work has been done to understand environmental factors such as diet. In particular, understanding the role of dietary glutamic acid consumption on co-morbidities in patients with schizophrenia is important, as evidence suggests that glutamic acid consumption may directly influence glutamatergic neurotransmission; a key neurotransmitter related to schizophrenia, its associated co-morbidities, and depression. Therefore, the aim of this study was to examine the potential relationship between dietary glutamic acid and depressive symptomatology in patients with schizophrenia, stratified by obesity status, due to its relationship with inflammation, antipsychotic use, and depressive symptoms. Methods: Subjects included in this analysis, were part of a parent cross-sectional study in which included three dietary recalls analyzed using protocols outlined as part of the National Health and Nutrition Examination Surveys (NHANES) standardized criteria. Additionally, body mass index (BMI), and Beck Depression Inventory were obtained at this visit. Subjects with a BMI ≥ 30 kg/m2 were included in the obesity group, and the relationship between glutamic acid consumption and BDI scores was analyzed after controlling for age, race, sex, antidepressant and antipsychotic use, and animal and vegetable protein intake which provide natural forms of dietary glutamic acid. Results: A total of 168 participants were included in this study, of which 42.5% were female and 52.9% were White. The mean BMI for the group as a whole was 33.5 ± 8.7 (kg/m2) and the mean BDI was 14.5 ± 10.2 (range 2-50). No differences were found between obesity groups, other than a greater hyperlipidemia, hypertension, and lower waist to hip ratio. Overall, no relationship was found between dietary glutamic acid and BDI scores, However, for non-obese participants, diets higher levels of glutamic acid were associated with greater depression symptomatology (p = 0.021). Conclusion: These preliminary results indicate a possible correlation between dietary glutamic acid a depressive symptoms in non-obese patients with schizophrenia, although further research is needed to specifically examine this relationship.

Could Dietary Glutamate Play a Role in Psychiatric Distress?

Glutamate is an amino acid that functions as an excitatory neurotransmitter. It has also been associated with somatic and psychiatric distress and is implicated in the pathophysiology of psychiatric disorders such as schizophrenia. Ingestion of dietary glutamate, such as monosodium glutamate (MSG), has been mechanistically linked with greater distress among patients with chronic pain conditions, though findings have been equivocal. Preliminary research suggests that an MSG-restricted diet confers beneficial effects on somatic symptoms and well-being for some individuals with chronic pain conditions. In addition to associations with somatic distress, glutamate has been associated with the onset and progression of psychiatric symptoms. Thus, the role of dietary glutamate in psychiatric distress represents an underdeveloped and potentially important area for future research aimed at clarifying pathophysiological mechanisms and identifying targets for dietary intervention in psychiatric illnesses.

Psychological predictors of memory decline in a racially and ethnically diverse longitudinal sample of older adults in the United States.

OBJECTIVES: In the United States, racial and ethnic disparities in memory dysfunction and Alzheimer disease are evident even after accounting for many risk factors. Psychological factors, such as psychological well-being, perceived control, depressive symptoms, and negative affect, may influence memory dysfunction, and associations may differ by race and ethnicity. This study examined whether psychological factors are differentially associated with episodic memory trajectories across racial and ethnic groups in the United States. METHODS/DESIGN: The National Health and Aging Trends Study (NHATS), is a US-representative, longitudinal study of Medicare-eligible adults 65+ years old. Analyses of 5 years of data, included a total of 9411 participants without dementia at baseline. Adjusting for relevant covariates, a linear mixed model estimated the associations between psychological predictors and a composite of immediate and delayed trials from a word list memory test. RESULTS: More depressive symptoms (B = -0.02), lower psychological well-being (B = 0.03), and lower perceived control (B = 0.05) were independently associated with lower initial memory. Depressive symptoms were associated with faster rate of memory decline (B = -0.01). Black (B = -0.34) and Hispanic (B = -0.28) participants evidenced lower initial memory level than whites, but only Hispanic (B = -0.04) participants evidenced faster memory decline than whites. There were no significant interactions between the psychological variables and race and ethnicity. CONCLUSIONS: Results extend previous studies showing racial and ethnic disparities in episodic memory trajectories, and the longitudinal effects of depressive symptoms on episodic memory in US samples. Epidemiological studies of cognitive aging should incorporate more psychological factors clarify cognitive decline and disparities.