Childhood cognitive ability and adult mental health in the British 1946 birth cohort

Cognitive ability in early life and risk of depression in adulthood: A systematic review and meta-analysis

BACKGROUND

There is an established association between cognitive ability and risk of depression, though the direction of this association is unclear. Measuring cognitive ability in childhood, prior to the diagnosis of depression, could help to understand whether childhood cognitive ability is associated with a later diagnosis of depression. This systematic review and meta-analysis explored the association between childhood cognitive ability and risk of depression in adulthood.

METHODS

We searched five databases to January 2024. We included studies that assessed cognitive ability in childhood (<18 years) and depression in adulthood. We excluded studies with very specific populations. We pooled each study's most-adjusted correlation coefficient in a random-effects meta-analysis. When studies reported a dichotomous outcome (depression/no depression), we converted the effect size to a correlation coefficient. Subgroup analyses were performed to explore sources of heterogeneity.

RESULTS

18 articles (19 cohorts) were included. There was no association between childhood cognitive ability and depression in adulthood (20 sample populations, N = 45,786, r = -0.04, 95 % CI = -0.09 to 0.01, p = 0.09). Neither age at cognitive assessment, length of follow-up, using a continuous/categorical measure of depression, or sex, significantly influenced the association. We rated most studies as having moderate risk of bias.

LIMITATIONS

We limited the literature search to studies written in English. Existing studies were also heterogeneous, often adjusting for a variety of covariates.

CONCLUSIONS

Our meta-analysis found no association between childhood cognitive ability and depression in adulthood. Future, longitudinal population-level studies should endeavour to control for potential mediators across the life-course (e.g., demographic and environmental factors).

Relationship between cognitive ability and emotional problems in the context of poverty: a Nigerian adolescent twin study

Although previous studies have identified negative relationships between cognitive ability and emotional problems (EP), mechanism explaining these relationships remained unclear. This study evaluated two explanatory models using bivariate moderation model-fitting analysis in a twin design. The resilience model suggests that high cognitive ability decreases the risk of EP in adverse settings, and the scarring model suggests that EP symptoms lead to persistent cognitive deficits following onset. The Standard Progressive Matrices Plus (SPM) and EP scale were administered to a sample of 3,202 twins (mean age = 14.62 ± 1.74 years) attending public schools in Nigeria. The results of bivariate moderation model-fitting analyses only supported the resilience model. Moderation effects were not significant in the scarring model when genetic and environmental influences were incorporated. The best-fitting bivariate moderation model assuming the resilience model yielded a genetic correlation of - 0.57 (95% CI =  - 0.40, - 0.84) with no significant environmental correlations. Moreover, the SPM moderated the environmental, not genetic, influences on EP, such that environmental influences were strong when protective factors were absent (low SPM) and weak when these were present (high SPM). These results indicate the need to develop targeted prevention and intervention strategies for EP in adolescents displaying low cognitive ability in deprived settings.

Childhood cognitive ability and self-harm and suicide in later life

Background

Self-harm and suicide remain prevalent in later life. For younger adults, higher early-life cognitive ability appears to predict lower self-harm and suicide risk. Comparatively little is known about these associations among middle-aged and older adults.

Methods

This study examined the association between childhood (age 11) cognitive ability and self-harm and suicide risk among a Scotland-wide cohort (N = 53037), using hospital admission and mortality records to follow individuals from age 34 to 85. Multistate models examined the association between childhood cognitive ability and transitions between unaffected, self-harm, and then suicide or non-suicide death.

Results

After adjusting for childhood and adulthood socioeconomic conditions, higher childhood cognitive ability was significantly associated with reduced risk of self-harm among both males (451 events; HR = 0.90, 95% CI [0.82, 0.99]) and females (516 events; HR = 0.89, 95% CI [0.81, 0.98]). Childhood cognitive ability was not significantly associated with suicide risk among those with (Male: 16 events, HR = 1.05, 95% CI [0.61, 1.80]; Female: 13 events, HR = 1.08, 95% CI [0.55, 2.15]) or without self-harm events (Male: 118 events, HR = 1.17, 95% CI [0.84, 1.63]; Female: 31 events, HR = 1.30, 95% CI [0.70, 2.41]).

Limitations

The study only includes self-harm events that result in a hospital admission and does not account for self-harm prior to follow-up.

Conclusions

This extends work on cognitive ability and mental health, demonstrating that these associations can span the life course and into middle and older age.

Updating the study protocol: Insight 46 - a longitudinal neuroscience sub-study of the MRC National Survey of Health and Development - phases 2 and 3

BACKGROUND

Although age is the biggest known risk factor for dementia, there remains uncertainty about other factors over the life course that contribute to a person's risk for cognitive decline later in life. Furthermore, the pathological processes leading to dementia are not fully understood. The main goals of Insight 46-a multi-phase longitudinal observational study-are to collect detailed cognitive, neurological, physical, cardiovascular, and sensory data; to combine those data with genetic and life-course information collected from the MRC National Survey of Health and Development (NSHD; 1946 British birth cohort); and thereby contribute to a better understanding of healthy ageing and dementia.

METHODS/DESIGN

Phase 1 of Insight 46 (2015-2018) involved the recruitment of 502 members of the NSHD (median age = 70.7 years; 49% female) and has been described in detail by Lane and Parker et al. 2017. The present paper describes phase 2 (2018-2021) and phase 3 (2021-ongoing). Of the 502 phase 1 study members who were invited to a phase 2 research visit, 413 were willing to return for a clinic visit in London and 29 participated in a remote research assessment due to COVID-19 restrictions. Phase 3 aims to recruit 250 study members who previously participated in both phases 1 and 2 of Insight 46 (providing a third data time point) and 500 additional members of the NSHD who have not previously participated in Insight 46.

DISCUSSION

The NSHD is the oldest and longest continuously running British birth cohort. Members of the NSHD are now at a critical point in their lives for us to investigate successful ageing and key age-related brain morbidities. Data collected from Insight 46 have the potential to greatly contribute to and impact the field of healthy ageing and dementia by combining unique life course data with longitudinal multiparametric clinical, imaging, and biomarker measurements. Further protocol enhancements are planned, including in-home sleep measurements and the engagement of participants through remote online cognitive testing. Data collected are and will continue to be made available to the scientific community.

The influence of childhood aspirations on the risk of developing psychotic disorders, substance use disorders, and dual diagnosis in adulthood based on the Metropolit 1953 Danish Male Birth Cohort

The study aims to investigate the association of aspiration for future occupation, socioeconomic position, and intellectual abilities with risk of dual diagnosis, psychosis, substance use disorder (SUD) in later life, and to explore if social and intellectual disadvantage modify any effect of childhood aspirations on outcomes. The study included 7177 Danish boys born in 1953. We investigated childhood aspirations (preference regarding future occupation), socioeconomic position (paternal social group), and intellectual abilities (Härnquist intelligence score) on outcomes with dual diagnosis, psychotic disorder, or SUD in Danish registers. Combinations of variables were used for a two-way and three-way analysis (high and low levels of exposure variables). Cox regression with age as the underlying time scale was used for analysis. The separate analysis showed no associations between childhood aspirations and outcomes. Boys with low intelligence scores had an increased risk of developing psychotic disorders (aHR 1.5, 95% CI 1.1-2.1) and SUD (aHR 1.8, 95% CI 1.5-2.1) compared to high intelligence scores. The interaction analyses showed that individuals with a combination of low intelligence score, high aspirations, and/or high paternal social group might have an increased risk of developing dual diagnosis, psychotic disorders, or SUD in later life. This result should be interpreted with caution as interaction variables were not overall significant with the outcome of dual diagnosis or psychotic disorder. The findings suggest that childhood abilities and social position could be associated with the development of psychotic disorders and SUD in later life, however, further studies are needed to address the temporality of the association to gain an understanding of the underlying mechanism of the association.

A lifecourse approach in examining the association between accumulation of adversity and mental health in older adulthood

BACKGROUND

There is evidence for a cumulative effect of adversities on mental health, however, less is known on the accumulating duration of exposure to adversity across the lifecourse on mental health in older adults.

METHODS

Using data from the 1946 British birth cohort study (N = 2745), we examined associations between the accumulation of adversity (birth-63 years) and mental health (emotional symptom, life satisfaction, affective wellbeing) in older adults (63-69 years). Accumulation of adversity was assessed as the number of adversities and duration of exposure (number of lifecourse stages exposed to any, economic, psychosocial, or physical adversity). Linear regression tested their association with mental health, adjusted for sex, childhood cognition and emotional problems, and educational attainment.

RESULTS

Increased number of adversities was associated with increased emotional symptoms (β = 0.08 [0.06, 0.10]), decreased life satisfaction (β = -0.14 [-0.16, -0.12]) and decreased affective wellbeing (β = -0.08 [-0.10, -0.06]). Each additional duration of exposure was associated with a 0.38 [0.12, 0.65] standard deviation (SD) increase in emotional symptoms, and a - 0.68 [-0.96, -0.39] and -0.43 SD [-0.68, -0.18] decrease in life satisfaction and affective wellbeing, respectively. Life satisfaction showed stronger associations with economic and psychosocial compared to physical adversity.

LIMITATIONS

Some limitations include selective drop-out and lack of ethnic diversity.

CONCLUSIONS

Efforts to improve mental health in older adults should focus on reducing the number of adversities, as well as considering previous exposure across different lifecourse stages, to prevent adversities from becoming chronic. Future research should also consider the clustering and co-occurrence of different adversities across the lifecourse.

Meta-analytic relations between personality and cognitive ability

Cognitive ability and personality are fundamental domains of human psychology. Despite a century of vast research, most ability-personality relations remain unestablished. Using contemporary hierarchical personality and cognitive abilities frameworks, we meta-analyze unexamined links between personality traits and cognitive abilities and offer large-scale evidence of their relations. This research quantitatively summarizes 60,690 relations between 79 personality and 97 cognitive ability constructs in 3,543 meta-analyses based on data from millions of individuals. Sets of novel relations are illuminated by distinguishing hierarchical personality and ability constructs (e.g., factors, aspects, facets). The links between personality traits and cognitive abilities are not limited to openness and its components. Some aspects and facets of neuroticism, extraversion, and conscientiousness are also considerably related to primary as well as specific abilities. Overall, the results provide an encyclopedic quantification of what is currently known about personality-ability relations, identify previously unrecognized trait pairings, and reveal knowledge gaps. The meta-analytic findings are visualized in an interactive webtool. The database of coded studies and relations is offered to the scientific community to further advance research, understanding, and applications.

Area disadvantage and mental health over the life course: a 69-year prospective birth cohort study

PURPOSE

Existing evidence on the mental health consequences of disadvantaged areas uses cross-sectional or longitudinal studies with short observation periods. The objective of this research was to investigate this association over a 69-year period.

METHODS

Data were obtained from the MRC National Survey of Health and Development (NSHD; the British 1946 birth cohort), which consisted of 2125 participants at 69 years. We assessed longitudinal associations between area disadvantage and mental health symptoms at adolescence and adulthood with use of multilevel modelling framework.

RESULTS

After adjustment for father's social class, for each one percentage increase in area disadvantage at age 4, there was a 0.02 (95% CI 0.001, 0.04) mean increase in the total score of the neuroticism scale at age 13-15. After adjustment for father's social class, adult socio-economic position, cognitive ability and educational attainment, a one percentage increase in change score of area disadvantage between age 4 and 26 was associated with a mean increase in the total Psychiatric Symptom Frequency score (MD 0.06; 95% CI 0.007, 0.11). Similar associations were observed with change scores between ages 4, 53, 60 and total General Health Questionnaire-28 score at age 53 (MD 0.05; 95% CI 0.01, 0.11) and 60-64 (MD 0.06; 95% CI 0.009, 0.11).

CONCLUSIONS

Cohort members who experienced increasing area disadvantage from childhood were at increased risk of poor mental health over the life course. Population-wide interventions aiming at improving social and physical aspects of the early neighbourhood environment could reduce the socio-economic burden of poor mental health.

Association of premorbid intelligence with level of functioning and illness severity in bipolar disorder

BACKGROUND

Bipolar disorder is a severe psychiatric syndrome defined by periodic mood shifts. Patients with bipolar disorder show cognitive impairments relative to healthy controls. The risk of developing schizophrenia, and partially also bipolar disorder, has previously been shown to increase with lower premorbid intelligence. It is not known if premorbid intelligence is associated with level of functioning and illness severity of people having developed bipolar disorder.

METHODS

We used multiple linear and ordinal regression to analyze how premorbid intelligence, as measured at conscription, associate with functional outcome and illness severity in Swedish male bipolar disorder patients (n = 788).

RESULTS

We found that lower premorbid intelligence is associated with lower percentage of time in work, after adjusting for age and bipolar subtype, and correcting for multiple comparisons. We also found a strong negative association with the total number of inpatient episodes and psychiatric comorbidity, but not with interepisodic remission, treatment with psychotherapy or lithium or the presence of any complicating socioeconomical factors. Adjusting for confounding genetic factors using polygenic risk scores for bipolar disorder and schizophrenia had no effect on the associations.

LIMITATIONS

This study lacks females and controls and may thus have lower generalizability.

CONCLUSION

In conclusion, premorbid intelligence is associated with both level of functioning and illness severity as well as comorbidity in bipolar disorder patients. Further research is needed to develop targeted interventions for this subgroup of bipolar disorder patients.

Childhood cognitive ability and self-harm and suicide in later life

Self-harm and suicide remain prevalent in later life. For younger adults, work has highlighted an association between higher early-life cognitive ability and lower self-harm and suicide risk. Comparatively little is known about its association with self-harm and suicide among older adults. Furthermore, most work has measured cognitive ability in early adulthood, raising issues of potential confounding by emerging psychiatric conditions. The present study examined the association between childhood (age 11) cognitive ability and self-harm and suicide risk among a Scotland-wide cohort of older adults (N = 53037), using health data linkage to follow individuals from age 34 to 85. Self-harm events were extracted from hospital admissions and suicide deaths were extracted from national mortality records. Multistate models were used to model transitions between unaffected, self-harm, and then suicide or non-suicide death, and to examine the association between childhood cognitive ability and each transition. After adjusting for childhood and adulthood socioeconomic conditions, higher childhood cognitive ability was significantly associated with reduced risk of self-harm among older females (N events = 516; HR = 0.90, 95% CI = [0.81, 0.99]). A similar, though non-significant, association was observed among older males (N events = 451; HR = 0.90, 95% CI = [0.82, 1.00]). Although suicide risk was higher among older adults experiencing self-harm, childhood cognitive ability was not significantly associated with suicide risk among either older adults experiencing no self-harm events (Male: N events = 118, HR = 1.17, 95% CI = [0.84, 1.63]; Female: N events = 31, HR = 1.30, 95% CI = [0.70, 2.41]) or those experiencing a self-harm event during follow-up (Male: N events = 16, HR = 1.05, 95% CI = [0.61, 1.80]; Female: N events = 13, HR = 1.08, 95% CI = [0.55, 2.14]). Higher suicide risk was significantly associated with covariates including higher adulthood deprivation and longer time in the self-harm state. These results extend work on cognitive ability and mental health, demonstrating that these associations can span across the life course and into older age.

Can Intelligence Affect Alcohol-, Smoking-, and Physical Activity-Related Behaviors? A Mendelian Randomization Study

People with high levels of intelligence are more aware of risk factors, therefore choosing a healthier lifestyle. This assumption seems reasonable, but is it true? Previous studies appear to agree and disagree. To cope with the uncertainty, we designed a mendelian randomization (MR) study to examine the causal effects of genetically proxied intelligence on alcohol-, smoking-, and physical activity (PA)-related behaviors. We obtained genome-wide association study (GWAS) datasets concerning these variables from separate studies or biobanks and used inverse-variance weighted (IVW) or MR-Egger estimator to evaluate the causal effects according to an MR protocol. The MR-Egger intercept test, MR-PRESSO, and funnel plots were employed for horizontal pleiotropy diagnosis. The Steiger test (with reliability test), Cochran's Q test, MR-PRESSO, and leave-one-out method were employed for sensitivity analysis. We found significant or potential effects of intelligence on alcohol dependence (OR = 0.749, p = 0.003), mental and behavioral disorders due to alcohol (OR = 0.814, p = 0.009), smoking (OR = 0.585, p = 0.005), and smoking cessation (OR = 1.334, p = 0.001). Meanwhile, we found significant or potential effects on walking duration (B = -0.066, p < 0.001), walking frequency (B = -0.055, p = 0.031), moderate PA frequency (B = -0.131, p < 0.001), and vigorous PA frequency (B = -0.070, p = 0.001), but all in a negative direction. In conclusion, our findings reinforce some existing knowledge, indicate the complexity of the health impacts of human intelligence, and underline the value of smoking and alcohol prevention in less intelligent populations. Given the existing limitations in this study, particularly the potential reverse causality in some estimations, re-examinations are warranted in future research.

The Power of Birth Cohorts to Study Risk Factors for Cognitive Impairment

PURPOSE OF REVIEW

Birth cohorts are studies of people the same time; some of which have continuously followed participants across the life course. These are powerful designs for studying predictors of age-related outcomes, especially when information on predictors is collected before these outcomes are known. This article reviews recent findings from these cohorts for the outcomes of cognitive function, cognitive impairment, and risk of dementia, in relation to prior cognitive function, and social and biological predictors.

RECENT FINDINGS

Cognitive function and impairment are predicted by a wide range of factors, including childhood cognition, education, occupational status and complexity, and biological factors, including genetic and epigenetic. The particular importance of high and rising blood pressure in midlife is highlighted, with some insight into brain mechanisms involved. Some limitations are noted, including sources of bias in the data. Despite these limitations, birth cohorts have provided valuable insights into factors across the life course associated with cognitive impairment.

Immediate and Sustained Effects of Neurofeedback and Working Memory Training on Cognitive Functions in Children and Adolescents with ADHD: A Multi-Arm Pragmatic Randomized Controlled Trial

OBJECTIVE

To evaluate the effects of neurocognitive training methods on targeted cognitive functions in children and adolescent with ADHD.

METHOD

A pragmatic four-arm randomized controlled trial compared two types of neurofeedback (Slow Cortical Potential and Live Z-score) and Working-memory training (WMT) with treatment as usual. N = 202 participants with ADHD aged 9 to 17 years were included. A battery of cognitive function tests was completed pretreatment, posttreatment, and after 6-months.

RESULTS

The effects of WMT on spatial and verbal working-memory were superior to neurofeedback and treatment as usual at posttreatment, but only partially sustained at follow-up. No other consistent effects were observed. We found no clear indications that effects were moderated by ADHD presentation, ongoing medication, age, or sex.

CONCLUSION

The sustained effects of neurocognitive training on cognitive functioning in children and adolescents with ADHD may be limited. Future research should focus on more personalized forms of neurocognitive training.

Influence of current physical exercise on the relationship between aging and episodic memory and fluid intelligence

The present study examined the effects of current physical exercise and age on episodic memory and fluid intelligence, assessed with a free-recall task and the Culture Fair Intelligence Test (Cattell, 1963) respectively, while statistically controlling for other cognitive reserve factors (educational level, leisure activities, and vocabulary level). Two hundred and eight participants aged 20 to 85 participated in the study. Physical exercise level was indexed by weekly frequency over the last 12 months using self-reported measurement (from none to 4 times a week). Overall, results show a beneficial effect of physical exercise especially from a weekly practice of 2 times, and significant interaction between physical exercise and age on episodic memory and fluid intelligence capacities indicating a reduced effect of age in more physically active participants. These results reinforce the view that physical exercise is a strong and specific reserve factor that reduces decline in some cognitive functions during aging.

The impact of COVID-19 on the psychological distress of youths in Japan: A latent growth curve analysis

BACKGROUND

This study expands on previous studies that have investigated the impact of the novel coronavirus disease (COVID-19) on mental health in two ways. We first model the change in mental health, then examine the various factors that predict changes in psychological distress.

METHOD

Longitudinal surveys were conducted once each in 2015, 2017, and 2019 on mothers and their children born between April 2000 and March 2001 (n = 1854), and three times in 2020 (February, July, and December) on the children in Japan. A latent growth curve model with four time points from December 2019 to December 2020 was used to depict the changes in the psychological distress of youths and to examine the factor associated with the level and change in psychological distress.

RESULTS

The psychological distress of youths increased from December 2019 to July 2020, especially among female youths, then decreased in December 2020. Initial health status and psychological traits were related to the initial level of psychological distress, but not the change. Gender was not related to the initial level of psychological distress but an increase in distress.

CONCLUSION

Although the effect size was small, gender was related to changes in distress during the COVID-19 pandemic. Other factors, such as health-related characteristics and personality traits, were associated with the level of distress before the pandemic but could not explain the changes in distress during the pandemic.

Maternal inflammatory and omega-3 fatty acid pathways mediate the association between socioeconomic disadvantage and childhood cognition

Poor cognitive outcomes in early childhood predict poor educational outcomes and diminished health over the life course. We sought to investigate (i) whether maternal metabolites predict child cognition, and (ii) if maternal metabolomic profile mediates the relationship between environmental exposures and child cognition. Metabolites were measured using nuclear magnetic resonance-based metabolomics in pregnant women from a population-derived birth cohort. Child cognition was measured at age 2 years. In 662 mother-child pairs, elevated inflammatory markers (β = -2.62; 95% CI -4.10, -1.15; P = 0.0005) and lower omega-3 fatty acid-related metabolites (β = 0.49; 95% CI 0.09, 0.88; P = 0.02) in the mother were associated with lower child cognition and partially mediated the association between lower child cognition and multiple risk factors common to socioeconomic disadvantage. Modifying maternal prenatal metabolic pathways related to inflammation and omega-3 fatty acids may offset the adverse associations between prenatal risk factors related to socioeconomic disadvantage and low child cognition.

Childhood neglect and trajectories of affective symptoms throughout adulthood: A British birth cohort study

BACKGROUND

Childhood maltreatment, including neglect, can affect an individual's mental health. However, there is a gap in current literature investigating the long-term, dynamic effects of childhood neglect on adult affective symptoms (AS).

METHOD

Data were used from the National Child Development Study (a British 1958 birth cohort). Childhood neglect was prospectively measured at ages 7 and 11. Five distinct trajectories of AS have been derived previously, using data from the Malaise Inventory Scale (at ages 23, 33, 42 and 50): 'no symptoms', 'persistent mild/moderate symptoms', 'low and increasing symptoms', 'high and increasing symptoms' and 'high and decreasing symptoms' (John et al., 2019). Multinomial logistic regressions were used to explore whether childhood neglect was associated with AS trajectory membership, while adjusting for a number of covariates.

RESULTS

Results revealed that childhood neglect was significantly associated with 'high and decreasing', 'high and increasing' and 'persistent mild/moderate' AS trajectories from young adulthood through midlife. There was no association with the 'low and increasing' AS trajectory. When testing for at age specific effects, neglect experienced at age 7 only, or at age 11 only, was predictive of 'high and decreasing symptoms' trajectory, whereas neglect experienced at both ages was predictive of 'persistent mild/moderate symptoms' trajectory.

CONCLUSIONS

Childhood neglect has negative long-lasting effects on trajectories of adult mental health. This finding has important implications for early intervention for individuals who have experienced childhood neglect.

Potential Predictors of Psychological Wellbeing in Elementary School Students

BACKGROUND

This study aimed to investigate the association of elementary school students' manipulative skill competency, cardiorespiratory fitness, and cognitive function with psychological wellbeing (PWB), as well as whether the association had gender differences.

METHODS

Participants were 291 fourth-grade students (166 boys vs. 125 girls; mean age = 9.770 years old; SD = 0.584) at two elementary schools from the province of Henan in China. The students' soccer skills in manipulative skill competency were assessed using the PE Metric Assessment Rubric, cardiorespiratory fitness was assessed by means of the PACER 15 m test, and cognitive function and PWB were assessed using the d2 test of attention and Warwick-Edinburgh Mental Wellbeing Scale, respectively. Data were analyzed with descriptive statistics and multiple linear regression models.

RESULTS

The result of linear regression models showed that soccer skills, cardiorespiratory fitness, and cognitive function were collectively associated with PWB for the total sample (F (5, 285) = 3.097, p < 0.01), boys (F (5, 160) = 1.355, p < 0.01), and girls (F (5, 119) = 2.132, p < 0.01). Furthermore, the standardized regression coefficients (β) indicated that cardiorespiratory fitness was the only significant contributor to PWB for the total sample (β = 0.119, t = 2.021, p < 0.05), but not for boys and girls. Soccer skills and cognitive function were not individual significant contributors to PWB for the total sample, boys, and girls.

CONCLUSIONS

Cardiorespiratory fitness was significantly associated with PWB, and there were no gender differences in the relationship of manipulative skill competency, cardiorespiratory fitness, and cognitive function with PWB in elementary school students. This study provides empirical evidence that improving cardiorespiratory fitness is an important intervention strategy to promote elementary school students' PWB.

Theory of Mind Ability and Socioeconomic Status, a Study of Street-Connected Children and Adolescents in Ecuador

Family socioeconomic status (SES) is closely associated with cognitive ability in children and adolescents. However, most of the research has come from high-income countries. There is only limited research on ‘street children’, who represent an aspect of low-SES particularly associated with low- and middle-income counties. The current research in Quito, Ecuador, compared a group of street-connected youth with a not street-connected control group on two different measures of theory of mind ability and verbal comprehension. Initial analysis revealed that the street-connected sample scored significantly below the level of the control sample for verbal comprehension. For the main analysis, street-connected youth were matched to control participants for age, sex, and verbal comprehension scores. The street-connected sample was found to perform significantly below the control sample on both measures of theory of mind. Furthermore, worse performance appeared to be linked to severity of symptoms of post-traumatic stress disorder (PTSD) within the street-connected sample. In conclusion, the association of relatively poor verbal comprehension with street-connectedness is consistent with existing research from high-income countries on SES gradients and cognitive development. In contrast, theory of mind ability, a core aspect of social cognition, may be particularly linked to the street-connectedness form of low SES that exists in many low- and middle-income countries.

Review of High-Intensity Interval Training for Cognitive and Mental Health in Youth

PURPOSE

High-intensity interval training (HIIT) has emerged as a time-efficient strategy to improve children's and adolescents' health-related fitness in comparison to traditional training methods. However, little is known regarding the effects on cognitive function and mental health. Therefore, the aim of this systematic review was to evaluate the effect of HIIT on cognitive function (basic information processing, executive function) and mental health (well-being, ill-being) outcomes for children and adolescents.

METHODS

A systematic search was conducted, and studies were eligible if they 1) included a HIIT protocol, 2) examined cognitive function or mental health outcomes, and 3) examined children or adolescents (5-18 yr). Separate meta-analyses were conducted for acute and chronic studies, with potential moderators (i.e., study duration, risk of bias, participant age, cognitive demand, and study population) also explored.

RESULTS

A total of 22 studies were included in the review. In acute studies, small to moderate effects were found for executive function (standardized mean difference [SMD], 0.50, 95% confidence interval [CI], 0.03-0.98; P = 0.038) and affect (SMD, 0.33; 95% CI, 0.05-0.62; P = 0.020), respectively. For chronic studies, small significant effects were found for executive function (SMD, 0.31; 95% CI, 0.15-0.76, P < 0.001), well-being (SMD, 0.22; 95% CI, 0.02-0.41; P = 0.029), and ill-being (SMD, -0.35; 95% CI, -0.68 to -0.03; P = 0.035).

CONCLUSIONS

Our review provides preliminary review evidence suggesting that participation in HIIT can improve cognitive function and mental health in children and adolescents. Because of the small number of studies and large heterogeneity, more high-quality research is needed to confirm these findings.

Intelligence, alcohol consumption, and adverse consequences. A study of young Norwegian men

Aims:

Research suggests that intelligence is positively related to alcohol consumption. However, some studies of people born around 1950, particularly from Sweden, have reported that higher intelligence is associated with lower consumption and fewer alcohol-related problems. We investigated the relationships between intelligence, alcohol consumption, and adverse consequences of drinking in young men from Norway (a neighboring Scandinavian country) born in the late 1970s.

Methods:

This analysis was based on the population-based Young in Norway Longitudinal Study. Our sample included young men who had been followed from their mid-teens until their late 20s (n = 1126). Measures included self-reported alcohol consumption/intoxication, alcohol use disorders (AUDIT), and a scale measuring adverse consequences of drinking. Controls included family background, parental bonding, and parents’ and peers’ drinking. Intelligence test scores—scaled in 9 “stanines” (population mean of 5 and standard deviation of 2)—were taken from conscription assessment.

Results:

Men with higher intelligence scores reported average drinking frequency and slightly fewer adverse consequences in their early 20s. In their late 20s, they reported more frequent drinking than men with lower intelligence scores (0.30 more occasions per week, per stanine, age adjusted; 95% CI: 0.12 to 0. 49). Intelligence was not associated with intoxication frequency at any age and did not moderate the relationships between drinking frequency and adverse consequences.

Conclusions:

Our results suggest that the relationship between intelligence and drinking frequency is age dependent. Discrepancies with earlier findings from Sweden may be driven by changes in drinking patterns.

The mediating effect of psychological distress on cognitive function and physical frailty among the elderly: Evidence from rural Shandong, China

BACKGROUND

Few studies have explored the underlying mechanism between physical frailty and cognitive function. The aim of this study is to explore the mediating role of psychological distress (PD) for the association between cognitive function and physical frailty among the elderly in rural China.

METHODS

A total of 3,242 rural older adults were included in the analysis. Logistic regression and Bootstrap analyses were employed to explore the association between cognitive function, PD and frailty, and the mediating role of PD.

RESULTS

This study found that the prevalence of frailty and cognitive impairment among the elderly in rural China was 18.0%, 22.4%. After adjusted for controlling variables, cognitive function was significantly associated with high level of PD, and elderly with higher level of PD had a higher probability of suffering from frailty. PD played a partially mediating effect in cognitive function and frailty and the mediating effect of PD can explain the 11.0% of the total effect of cognitive function on frailty.

LIMITATIONS

The data were cross-sectional, thus the causal relationship between variables could not be determined. The main variables in this study were measured by self-report information, which might result in recall bias.

CONCLUSIONS

This study provide evidence that the effect of cognitive function on physical frailty was partially mediated by PD among the elderly in rural China. Primary health care should strengthen the screening of PD characterized by depression and anxiety, and strive to improve the physical and psychological well-being of rural elderly in China.

Accumulation of affective symptoms and midlife cognitive function: The role of inflammation

BACKGROUND

The aim of the present study was to test whether C-Reactive Protein (CRP), a proxy measure of inflammation, is elevated in people with higher childhood and adulthood affective symptoms and whether elevated CRP predicts midlife cognitive function.

METHODS

Data were used from the National Child Development Study (n = 6276). Measures of memory, verbal fluency, information processing speed and accuracy were available in midlife (age 50). Affective symptoms were assessed in childhood (ages 7, 11, 16) and in adulthood (ages 23, 33, 42, 50). The level of plasma CRP was measured at age 44. Pathway models, unadjusted and fully adjusted for sex, education, childhood socioeconomic position, childhood cognitive ability and affective symptoms at age 50, were fitted to test direct associations between affective symptoms and midlife cognitive function, and indirect associations via the inflammatory pathway (CRP level).

RESULTS

In a fully adjusted model, there were significant indirect associations between adulthood affective symptoms and immediate memory (β = -0.01, SE = 0.003, p = .03) and delayed memory (β = -0.01, SE = 0.004, p = .03) via CRP. In addition, there were significant indirect associations between affective symptoms in childhood and immediate memory (β = -0.001, SE = 0.00, p = .03) and delayed memory (β = -0.001, SE = 0.001, p = .03), via adulthood affective symptoms and associated CRP. Independent of CRP, there was a significant direct association between adulthood affective symptoms and information processing errors (β = 0.47, SE = 0.21, p = .02). There were no direct or indirect associations between affective symptoms and verbal fluency or information processing speed.

CONCLUSIONS

CRP at age 44 is elevated in people with higher affective symptoms from age 7 to 42, and elevated CRP is associated with poorer immediate and delayed memory at age 50.

Effects of affective symptoms in adolescence and adulthood on trajectories of cognitive function from middle to late adulthood

BACKGROUND

Little is known about the link between affective symptoms and cognitive function across the life course. This study aims to investigate whether affective symptoms in adolescence and adulthood predict trajectories of cognitive function from middle to late-adulthood.

METHODS

Data from the MRC National Survey of Health and Development (NSHD), a cohort of 5362 individuals born in mainland UK in 1946, were utilised. Linear mixed models were used to model cognitive trajectories (memory and processing speed) over a three-decade period (from 43 to 69) and to test effects of affective symptoms in adolescence (ages 13-15) and adulthood (ages 36 and 43) on cognitive function at first testing (age 43) and decline in cognitive function (from 43 to 69). Models were adjusted for sex, childhood cognition, childhood socioeconomic position, and education.

RESULTS

A quadratic model best fitted memory and processing speed data. Models revealed that adolescent affective symptoms were associated with lower memory (b = -1.11, SE = 0.53, p = .04) and processing speed (b = -18.17, SE = 7.53, p = .02) at first cognitive testing, but not with rates of decline from 43 to 69. There were no significant associations between adult affective symptoms and cognitive trajectories.

LIMITATIONS

Missing data is a potential limitation of this study. This was dealt with using maximum likelihood estimation and multiple imputation.

CONCLUSIONS

Findings suggest that adolescent, but not adult, affective symptoms are important predictors of cognitive function in midlife, but not rate of cognitive decline. This highlights the importance of early intervention to manage mental health in adolescence to protect later cognitive function.

Longitudinal associations of affective symptoms with mid-life cognitive function: evidence from a British birth cohort

BACKGROUND

Affective disorders are associated with poorer cognition in older adults; however, whether this association can already be observed in mid-life remains unclear.

AIMS

To investigate the effects of affective symptoms over a period of 30 years on mid-life cognitive function. First, we explored whether timing (sensitive period) or persistence (accumulation) of affective symptoms predicted cognitive function. Second, we tested how different longitudinal trajectories of affective symptoms were associated with cognitive function.

METHOD

The study used data from the National Child Development Study. Memory, verbal fluency, information processing speed and accuracy were measured at age 50. Affective symptoms were measured at ages 23, 33, 42 and 50 and used to derive longitudinal trajectories. A structured modelling approach compared a set of nested models in order to test accumulation versus sensitive period hypotheses. Linear regressions and structural equation modelling were used to test for longitudinal associations of affective symptoms with cognitive function.

RESULTS

Accumulation of affective symptoms was found to be the best fit for the data, with persistent affective symptoms being associated with poorer immediate memory (b = -0.07, s.e. = 0.03, P = 0.01), delayed memory (b = -0.13, s.e. = 0.04, P < 0.001) and information processing accuracy (b = 0.18, s.e. = 0.08, P = 0.03), but not with information processing speed (b = 3.15, s.e. = 1.89, P = 0.10). Longitudinal trajectories of repeated affective symptoms were associated with poorer memory, verbal fluency and information processing accuracy.

CONCLUSIONS

Persistent affective symptoms can affect cognitive function in mid-life. Effective management of affective disorders to prevent recurrence may reduce risk of poor cognitive outcomes and promote healthy cognitive ageing.

DECLARATION OF INTEREST

None.

Intelligence in young adulthood and alcohol use disorders in a prospective cohort study of Danish men: the role of psychiatric disorders and parental psychiatric history

OBJECTIVES

The aims were to estimate the association between intelligence measured in young adulthood and risk of alcohol use disorders (AUD) in men and to investigate the potential modification of this association by psychiatric disorders, parental AUD and parental psychiatric disorders.

DESIGN

Prospective cohort study based on a linkage of intelligence test scores from draft board examinations and register data on AUD diagnoses during 36 years of follow-up.

SETTING

Denmark.

PARTICIPANTS

3287 Danish men from the Copenhagen Perinatal Cohort (born 1959-1961) who appeared before the draft board at a mean age of 18.7 years.

PRIMARY OUTCOME MEASURE

First registration with AUD during follow-up was the primary outcome. Information on AUD was based on diagnoses retrieved from national hospital and outpatient treatment registers, defined according to the International Classification of Diseases.

RESULTS

361 (11.0%) men were registered with AUD during follow-up. Low intelligence scores were associated with increased odds of AUD adjusting for parental AUD, parental psychiatric disorders, maternal smoking during pregnancy, birth weight, maternal age at birth, parity and childhood socioeconomic position (OR per SD decrease in intelligence=1.69, 95% CI 1.49 to 1.92). Separate analyses indicated significant interaction (p<0.001) between intelligence and psychiatric disorders. The adjusted OR per SD decrease in intelligence score was 2.04 (95% CI 1.67 to 2.49) in men without other psychiatric disorders whereas the OR was 1.21 (95% CI 1.01 to 1.46) in men with other psychiatric disorders. No interaction was found between intelligence and parental AUD or between intelligence and parental psychiatric disorders.

CONCLUSIONS

The association between intelligence in young adulthood and AUD is modified by other psychiatric disorders as low intelligence is primarily a risk factor for men without other psychiatric disorders. Future studies should take other psychiatric disorders into account when investigating associations between intelligence and AUD.

The roles of non-cognitive and cognitive skills in the life course development of adult health inequalities

Previous research has suggested that greater cognitive skill is protective against the development of socioeconomic health inequalities across the life course, but the relative role of non-cognitive skills has been less investigated in this context. Using the prospective UK 1958 National Child Development Study (N = 18,558), higher factor scores for adolescent non-cognitive skills (NCS; i.e. a combination of work habits and pro-social behaviours) and mean cognitive skill (CS) at age 16 were examined with a path analysis model in relation to socioeconomic status (SES) across the life course (at ages 16, 33 and 50) and poor self-reported health at age 50. Adjusting for adolescent NCS explained over a third of the association between education and health, but the path between social class at age 50 and health was unaffected. Adjustment for CS explained larger proportions of the paths to adult health inequalities; and paths between CS and SES across the life course were stronger than the same paths with NCS. However, NCS was still independently associated with paths to later health inequalities in fully adjusted models, and both types of skill had equivalent inverse direct effects with poor health (OR: 0.82 [95% CI 0.73,0.93] vs 0.83 [0.72,0.96], respectively). Since NCS retained independent associations with SES and health across the life course, they could be a target for policies aimed at ameliorating the production of health inequalities for a wide range of children, regardless of their cognitive skill.

Early-life predictors of retirement decisions and post-retirement health

It remains unclear whether retirement circumstances are associated with better or worse post-retirement health. This is partly due to confounding between measures of retirement circumstances and a tendency to account only for covariates around retirement age. The present study examined the contributions of both retirement age and retirement type, independently, to post-retirement health around age 77 years. It also examined whether these contributions remain once earlier life-course factors – social class, cognitive ability and education – were accounted for. Our sample was 742 Scottish people who took part in the Scottish Mental Survey 1947. In a path model including life-course predictors, retirement type (reason), but not age, significantly predicted post-retirement health, with ill-health retirement associated with poorer physical (β = 0.455, 95% CI [0.313, 0.597], p < 0.001) and mental health (β = 0.339, 95% CI [0.191, 0.486], p < 0.001), and redundancy retirement associated with poorer physical health only (β = 0.200, 95% CI [0.069, 0.331], p = 0.004). Of the life-course predictors, higher adult social class was associated with later retirement (β = 0.115, 95% CI [0.034, 0.196], p = 0.006) and higher childhood cognitive ability was associated with increased odds of voluntary retirement (OR = 1.054, 95% CI [1.005, 1.105], p = 0.032), but no indirect contribution to health (mediated by retirement circumstances) was significant. At the same time, higher childhood cognitive ability directly predicted better post-retirement physical health (β = -0.110, 95% CI [-0.216, -0.004], p = 0.041), independently of retirement circumstances. This study demonstrates the importance of considering retirement circumstances beyond age, and of accounting for confounding between retirement circumstances and earlier life-course factors.

•

Retirement type, not age, predicted post-retirement physical and mental health.

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Higher childhood cognitive ability predicted better post-retirement physical health.

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Retirement circumstances did not mediate associations with post-retirement health.

Childhood language development and later alcohol use behaviors

BACKGROUND

Studies have shown a correlation between language abilities and alcohol use; however, results are inconsistent. A recent study using a discordant twin design showed an association between early child language development and later alcohol use behaviors; i.e., the twin with more advanced language abilities was more likely to try alcohol earlier in adolescence (Latvala et al., 2014). The authors suggested that this could result from better socialization of individuals with greater language abilities, which could lead to more opportunities for alcohol experimentation. The findings by Latvala et al. raise interesting questions, but the study has limitations, and replication is needed.

METHOD

We aimed to replicate and build upon these results utilizing 488 same sex twin pairs from the Colorado Longitudinal Twin Study, a longitudinal sample with quantitative measures of language abilities starting when the twins were 14 months old.

RESULTS

We found no significant correlations between a latent measure of child language abilities or measures of general cognitive ability at ages 14, 20, and 24 months and a latent alcohol use variable at ages 17 and 22 years.

CONCLUSION

Our results did not replicate the association between early language ability and later alcohol use reported by Latvala et al. Possible reasons for differing results across samples, including varying cultural norms as well as differences in educational attainment, peer influences, and novelty seeking, were discussed.

Correlates of Adult Vocabulary Task Performance: Findings from a British Cohort

This study explored a longitudinal data set of 4361 adults (2119 males and 2239 females) to examine factors that influence adult vocabulary task performance. Data were collected at birth, in childhood (age 10 years), during teenage years (age 16 years), and in adulthood (ages 30, 34, and 42 years) to examine the effects of family social status, childhood cognitive ability, teenager locus of control, psychological distress, educational qualifications, and occupational prestige in adulthood on an adult vocabulary task-an index of crystallized intelligence. Structural equation modeling showed that childhood cognitive ability, teenager locus of control, education, and occupation were all significant and direct predictors of adult vocabulary task performance. Parental social status affected the outcome variable mediated through educational qualifications. The strongest predictor of adult vocabulary task performance was childhood cognitive ability, followed by educational qualifications and locus of control. Finally, limitations were acknowledged.

Lifetime affective problems and later-life cognitive state: Over 50 years of follow-up in a British birth cohort study

BACKGROUND

Affective problems increase the risk of dementia and cognitive impairment, yet the life course dimension of this association is not clearly understood. We aimed to investigate how affective problems across the life course relate to later-life cognitive state.

METHODS

Data from 1269 participants from the Medical Research Council National Survey of Health and Development (NSHD, the British 1946 birth cohort) were used. Prospectively-assessed measures of affective symptoms spanning ages 13-69 and categorised into case-level thresholds. Outcomes consisted of a comprehensive measure of cognitive state (Addenbrooke's Cognitive Examination (ACE-III)), verbal memory, and letter search speed and accuracy at age 69.

RESULTS

Complementary life course models demonstrated that having 2 or more case-level problems across the life course was most strongly associated with poorer cognitive outcomes, before and after adjusting for sex, childhood cognition, childhood and midlife occupational position and education.

LIMITATIONS

A disproportionate loss to follow-up of those who had lower childhood cognitive scores may have led to underestimation of the strength of associations.

DISCUSSION

Using a population-based prospective study we provide evidence that recurrent lifetime affective problems predicts poorer later-life cognitive state, and this risk can be already manifest in early old age (age 69). Our findings raise the possibility that effective management to minimise affective problems reoccurring across the life course may reduce the associated risk of cognitive impairment and decline.

Early-life adversity, later-life mental health, and resilience resources: a longitudinal population-based birth cohort analysis

ABSTRACTBackground:Robust and persistent links between early-life adversities and later-life mental distress have previously been observed. Individual and social resources are associated with greater mental health and resilience. This study aimed to test these resources as moderators and mediators of the association between childhood psychosocial adversity and later-life mental distress.

METHODS

Participant data came from the Medical Research Council National Survey of Health and Development, a nationally-representative birth cohort study. The General Health Questionnaire-28 (GHQ-28) captured mental distress at ages 53, 60-64, and 68-69. An eight-item cumulative psychosocial adversity score was created (0, 1, 2, ≥3 adversities). Individual (i.e., education, occupational status, physical activity) and social (i.e., social support, neighborhood cohesion) resources were examined as mediators and moderators of CPA and GHQ-28 in longitudinal multilevel models.

FINDINGS

Greater adversity was associated with an average GHQ-28 score increase of 0.017, per unit adversity (β = 0·017, p < 0·001, 95% CI 0·011, 0·022). Lower mental distress was associated with higher levels of physical activity, occupational status, education, social support, and neighborhood cohesion. There was no evidence that resources moderated the relationship between GHQ-28 and adversity. All resources, save for physical activity and occupational status, partly mediated this relationship.

CONCLUSIONS

Individual and social resources were associated with lower mental distress. They did not modify, but partly mediated the association between childhood adversity and adult mental distress. Social support was the most important mediator, suggesting that interventions to promote greater social support may offset psychosocial adversities experienced in childhood to foster better mental health in older adults.

Physical and psychosocial factors associated with depression among adults with type 2 diabetes mellitus at a Federally Qualified Healthcare Center

PURPOSE

The purpose of this study is to examine the prevalence of depression and physical and psychosocial factors associated with depression among adults with Type 2 Diabetes Mellitus (T2DM).

METHODS

The sample included 421 patients with T2DM at a Federally Qualified Healthcare Center in a southern state. The Patient Health Questionnaire (PHQ-9) was used to measure the severity of depression.

RESULTS

The multiple logistic regression analyses revealed that the likelihood of depression increased as the level of pain increased and as the level of ambulation difficulties increased. The likelihood of depression increased as the number of traumatic events increased and as the number of SES-related stressors increased. Expectedly, the likelihood of depression decreased as levels of self-esteem increased.

CONCLUSIONS

The findings support that health care providers developing care plans for individuals with diabetes need to include assessments and interventions that address both the physical and psychosocial needs of patients.

The interplay between cognitive ability, alcohol consumption, and health characteristics

BACKGROUND

Higher cognitive ability is associated with favourable health characteristics. The relation between ability and alcohol consumption, and their interplay with other health characteristics, is unclear. We aimed to assess the relationship between cognitive ability and alcohol consumption and to assess whether alcohol consumption relates differently to health characteristics across strata of ability.

METHODS

For 63 120 Norwegian males, data on cognitive ability in early adulthood were linked to midlife data on alcohol consumption frequency (times per month, 0-30) and other health characteristics, including cardiovascular risk factors and mental distress. Relations were assessed using linear regression and reported as unstandardised beta coefficients [95% confidence interval (CI)].

RESULTS

The mean ± s.d. frequency of total alcohol consumption in the sample was 4.0 ± 3.8 times per month. In the low, medium, and high group of ability, the frequencies were 3.0 ± 3.3, 3.7 ± 3.5, and 4.7 ± 4.1, respectively. In the full sample, alcohol consumption was associated with physical activity, heart rate, fat mass, smoking, and mental distress. Most notably, each additional day of consumption was associated with a 0.54% (0.44-0.64) and 0.14% (0.09-0.18) increase in the probability of current smoking and mental distress, respectively. In each strata of ability (low, medium, high), estimates were 0.87% (0.57-1.17), 0.48% (0.31-0.66) and 0.49% (0.36-0.62) for current smoking, and 0.44% (0.28-0.60), 0.10% (0.02-0.18), and 0.09% (0.03-0.15) for mental distress, respectively.

CONCLUSIONS

Participants with low cognitive ability drink less frequently, but in this group, more frequent alcohol consumption is more strongly associated with adverse health characteristics.

Young adult cognitive ability and subsequent major depression in a cohort of 666,804 Danish men

BACKGROUND

Early life cognitive ability (CA) might influence the risk of developing major depression (MD). The aim was to investigate the association between young adult CA and subsequent MD in relation to different MD disease characteristics.

METHODS

Information on CA was assessed at conscription board examinations 1957-1984 (mean age 19 years) and information on MD was based on hospital diagnosis retrieved from Danish Patient registers 1969-2015. Associations between CA and MD were examined using Cox regression analyses.

RESULTS

A total of 666,804 men (born 1939-1959) were followed and 25,841 (3.9%) developed MD during a mean follow-up of 40.8 years. Lower CA was associated with an increased risk of incident MD. The association was stronger for early-onset (<60 years) (HR_{per1SDdecrease} = 1.23; 95%CI:1.21,1.24) compared to late-onset (≥60 years) MD (HR_{per1SDdecrease} = 1.14; 95%CI:1.11,1.16), but CA was not related to number of depressive episodes. The association was stronger for single depressive episodes (HR_{per1SDdecrease} = 1.21; 95%CI:1.19,1.23) compared to recurrent depression (HR_{per1SDdecrease} = 1.13; 95%CI:1.09,1.16), while the strength of the association did not differ according to MD disease severity (ICD10: mild, moderate, and severe depression).

LIMITATIONS

The study sample only included men and only MD cases diagnosed at hospital were included which limits the generalizability.

CONCLUSION

Low CA could be a risk factor for especially early onset MD in men, whereas the influence of CA on re-occurrence seems less strong. Lower pre-morbid CA increases the risk of MD and should therefore be part of the depression risk assessment in clinical practice.

The effect of cognitive demand on performance of an executive function task following wild blueberry supplementation in 7 to 10 years old children

The cognitive benefits of acute flavonoid interventions have been well documented, however, research to date has found that, depending on developmental stage, these benefits manifest themselves in different cognitive domains. It is argued that the lack of global cognitive effects following flavonoid intervention may be a result of insufficient task sensitivity for those domains where no benefits are found. In children, executive function is a cognitive domain which has shown little apparent benefit following flavonoid intervention. Here, we describe a Modified Attention Network Task (MANT) designed to vary levels of cognitive demand across trials in order to investigate whether flavonoid related benefits can be shown for executive function when task sensitivity is carefully manipulated. Twenty-one children were recruited to a double blind cross-over study consuming 30 g freeze dried blueberry powder (WBB) or placebo before being tested at 3 hours. Performance in the WBB condition was found to be significantly faster in comparison to placebo particularly on more cognitively demanding incongruent and high load trials. Trials in which a visual cue alerted participants to the imminent appearance of the target also showed better performance following WBB administration. We conclude that WBB administration can enhance executive function during demanding elements of a task, but that the complexity and demand of the task as a whole may be equally important to performance.

Early vulnerabilities for psychiatric disorders in elementary schoolchildren from four Brazilian regions

PURPOSE

The purpose of the study is to identify early vulnerabilities for psychiatric disorders among Brazilian elementary school children, controlling for familial and community adversities.

METHODS

This is a cross-sectional study examining the association between child psychiatric disorders and potential early vulnerabilities (disability, low intellectual quotient, and negative dimensions of the temperament trait self-directedness (low resourcefulness, low purposefulness, low enlightened second nature), controlling for the potential confounders: familial and community adversities.

SAMPLE

Four probabilistic samples of second-to-sixth grade students from public schools in four towns from different Brazilian regions (N = 1620). The following instruments were applied: the K-SADS-PL (to assess child/adolescent psychiatric disorders); the Ten-Question Screen (to measure child disability); three structured questions used as proxy of self-directedness; and the reduced version of the WISC-III to measure IQ. To evaluate familial/community adversities: Self-Report Questionnaire-SRQ-20 (to assess maternal/primary caretaker anxiety/depression); questions derived from structured questionnaires (to measure child abuse, marital physical violence, neighborhood violence); Brazilian Association of Research Companies questionnaire (to evaluate poverty/socioeconomic status). Trained psychologists interviewed mothers/primary caretakers and evaluated children/adolescents individually.

RESULTS

A final logistic regression model showed that children/adolescents with low resourcefulness, low purposefulness, low enlightened second nature, lower IQ and disability were more likely to present any child psychiatric disorders.

CONCLUSION

Early vulnerabilities such as low IQ, presence of disability, and dimensions of temperament were associated with psychiatric disorders among Brazilian elementary school children, after controlling for familial and ecological confounders. These early vulnerabilities should be considered in mental health prevention/intervention programs in low-middle-income countries like Brazil.

Catechol O-methyltransferase (COMT) functional haplotype is associated with recurrence of affective symptoms: A prospective birth cohort study

BACKGROUND

Catechol-O-methyltransferase (COMT) polymorphisms play an essential role in dopamine availability in the brain. However, there has been no study investigating whether a functional four-SNP (rs6269-rs4633-rs4818-rs4680) haplotype is associated with affective symptoms over the life course.

METHODS

We tested this using 2093 members of the Medical Research Council National Survey of Health and Development (MRC NSHD), who had been followed up since birth in 1946, and had data for COMT genotypes, adolescent emotional problems (age 13-15) and at least one measure of adult affective symptoms at ages 36, 43, 53, or 60-64 years. First, differences in the levels of affective symptoms by the functional haplotype using SNPs rs6269, rs4818, and rs4680 were tested in a structural equation model framework. Second, interactions between affective symptoms by COMT haplotype were tested under an additive model. Finally, a quadratic regressor (haplotype2) was used in a curvilinear model, to test for a possible inverted-U trend in affective symptoms according to COMT-related dopamine availability.

RESULTS

Women had a significant interaction between COMT haplotypes and adolescent emotional problem on affective symptoms at age 53. Post hoc analysis showed a significant positive association between adolescent emotional problems and affective symptoms at age 53 years in the middle dopamine availability group (valA/valB or met/met; β = .11, p = .007). For men, no significant interactions were observed.

CONCLUSIONS

Combination of the COMT functional haplotype model and inverted-U model may shed light on the effect of dopaminergic regulation on the trajectory of affective symptoms over the life course.

Fat mass and obesity-associated (FTO) rs9939609 polymorphism modifies the relationship between body mass index and affective symptoms through the life course: a prospective birth cohort study

Although bi-directional relationships between high body mass index (BMI) and affective symptoms have been found, no study has investigated the relationships across the life course. There has also been little exploration of whether the fat mass and obesity-associated (FTO) rs9939609 single-nucleotide polymorphism (SNP) is associated with affective symptoms and/or modifies the relationship between BMI and affective symptoms. In the MRC National Survey of Health and Development (NSHD), 4556 participants had at least one measure of BMI and affective symptoms between ages 11 and 60-64 years. A structural equation modelling framework was used with the BMI trajectory fitted as latent variables representing BMI at 11, and adolescent (11-20 years), early adulthood (20-36 years) and midlife (36-53 years) change in BMI. Higher levels of adolescent emotional problems were associated with greater increases in adult BMI and greater increases in early adulthood BMI were associated with higher subsequent levels of affective symptoms in women. The rs9939609 risk variant (A allele) from 2469 participants with DNA genotyping at age 53 years showed mostly protective effect modification of these relationship. Increases in adolescent and early adulthood BMI were generally not associated with, or were associated with lower levels, of affective symptoms in the FTO risk homozygote (AA) group, but positive associations were seen in the TT group. These results suggest bi-directional relationships between higher BMI and affective symptoms across the life course in women, and that the relationship could be ameliorated by rs9939609 risk variant.

Financial circumstances, mastery, and mental health: Taking unobserved time-stable influences into account

This paper examines whether low income and subjective financial strain are associated with mental health, as well as whether mastery weakens this association. We analyze three waves of a large sample of Canadians and utilize random and fixed effects regression strategies to assess bias introduced by unobserved time-stable confounders. In random effects models, both low income and subjective financial strain are associated with distress and anger. In fixed effects models that control for all time-stable confounders, the effect of low income is reduced to non-significance for both outcomes. The effect of subjective strain is also reduced in fixed effects models, but remained statistically significant. Sobel tests indicated that the effect of subjective strain on mental health is transmitted through mastery, but this indirect path is modest in magnitude. When interactions are tested, mastery weakens the association between subjective strain and distress, and this effect is robust to the influence of time-stable controls, but mastery does not buffer the subjective strain-anger relationship in either random or fixed-effects models. Finally, moving below the low income threshold increases anger for low mastery individuals, but seems to reduce anger when moving below the low income threshold is coupled with increases in mastery. Collectively, our findings demonstrate the importance of assessing the influence of unobserved time-stable confounders in stress research. Further, discrepancies in the moderating role of mastery reinforce calls for the assessment of multiple outcomes in mental health research.

Mental Well-Being Differences in Cohabitation and Marriage: The Role of Childhood Selection

Prior studies have found that marriage benefits well-being, but cohabitation may provide similar benefits. An analysis of the British Cohort Study 1970, a prospective survey following respondents to age 42, examines whether partnerships in general, and marriage in particular, influence mental well-being in midlife. Propensity score matching indicates whether childhood characteristics are a sufficient source of selection to eliminate differences in well-being between those living with and without a partner and those cohabitating and married. The results indicate that matching on childhood characteristics does not eliminate advantages to living with a partner; however, matching eliminates differences between marriage and cohabitation for men and women more likely to marry. On the other hand, marriage may provide benefits to women less likely to marry unless they have shared children and are in long-lasting partnerships. Hence, childhood selection attenuates differences between cohabitation and marriage, except for women less likely to marry.

Cognitive profiles in childhood and adolescence differ between adult psychotic and affective symptoms: a prospective birth cohort study

BACKGROUND

Differences between verbal and non-verbal cognitive development from childhood to adulthood may differentiate between those with and without psychotic symptoms and affective symptoms in later life. However, there has been no study exploring this in a population-based cohort.

METHOD

The sample was drawn from the MRC National Survey of Health and Development, and consisted of 2384 study members with self-reported psychotic experiences and affective symptoms at the age of 53 years, and with complete cognitive data at the ages of 8 and 15 years. The association between verbal and non-verbal cognition at age 8 years and relative developmental lag from age 8 to 15 years, and both adult outcomes were tested with the covariates adjusted, and mutually adjusted for verbal and non-verbal cognition.

RESULTS

Those with psychotic experiences [thought interference (n = 433), strange experience (n = 296), hallucination (n = 88)] had lower cognition at both the ages of 8 and 15 years in both verbal and non-verbal domains. After mutual adjustment, lower verbal cognition at age 8 years and greater verbal developmental lag were associated with higher likelihood of psychotic experiences within individuals, whereas there was no association between non-verbal cognition and any psychotic experience. In contrast, those with case-level affective symptoms (n = 453) had lower non-verbal cognition at age 15 years, and greater developmental lag in the non-verbal domain. After adjustment, lower non-verbal cognition at age 8 years and greater non-verbal developmental lag were associated with higher risk of case-level affective symptoms within individuals.

CONCLUSIONS

These results suggest that cognitive profiles in childhood and adolescence differentiate psychiatric disease spectra.

School Achievement, IQ, and Risk of Alcohol Use Disorder: A Prospective, Co-Relative Analysis in a Swedish National Cohort

OBJECTIVE

Most studies suggest that poor cognitive functioning in adolescence increases risk of alcohol use disorders (AUDs). We seek to clarify the causes of this association.

METHOD

In Swedish individuals born from 1972 to 1990 in whom cognitive functioning was assessed by school achievement at age 16 years (males and females, N = 1,796,048) and by IQ at ages 18-20 (males, N = 554,644), we examined the hazard ratio (HR) for AUD ascertained from public registries. We examined and modeled risk of AUD in cousins, full siblings, and monozygotic twin pairs discordant for school achievement and IQ scores.

RESULTS

In males and females, HRs for AUD per standard deviation of increasing school achievement equaled 0.47 (95% CI [0.46, 0.47]) and 0.52 (95% CI [0.51, 0.53]), respectively. In males, the HR for AUD per standard deviation of increasing IQ was 0.54 (95% CI [0.53, 0.55]). Excluding onsets of AUD within 5 years of the cognitive evaluation did not weaken the association, nor did controlling for alcohol intake and problems at IQ assessment. The HRs for AUD in relative pairs were higher than those observed in the population but significantly less than unity. We predicted the following HRs for AUD in discordant monozygotic twins for school achievement in males and females and for IQ in males: 0.66 (95% CI [0.62, 0.70]), 0.67 (95% CI [0.62, 0.73]), and 0.72 (95% CI [0.65, 0.79]), respectively.

CONCLUSIONS

Cognitive ability in adolescence, assessed by two different measures, strongly predicts risk of AUD. This association cannot be explained by early symptoms of AUD impairing performance. Co-relative analyses suggest that this association arises partly from familial confounding and partly from a causal impact of low cognitive ability on AUD risk.

Does gender moderate the association between intellectual ability and accidental injuries? Evidence from the 1953 Stockholm Birth Cohort study

In this paper, we test for gender differences in the effects of intellectual ability on accidental injury risks using longitudinal data from the 1953 Stockholm Birth Cohort study (n=14,294). Intellectual ability was measured using IQ tests issued during a school survey at age ∼13, and outcome and covariate data was collected via record linkage to population and health registers, following the cohort from childhood to 55 years of age. We used ICD codes to identify accidental injuries resulting in hospital admissions and deaths, and shared frailty models to quantify the effects of IQ, while allowing for within-individual dependencies and recurrent events. The models included tests for the moderating effects of gender, as well as childhood family variables (parental socioeconomic status), and cohort member mediators (highest achieved education, socioeconomic status and income at the time of the event). The results indicate an inverse association between childhood IQ and subsequent accidental injury events, where 1 SD decrease in IQ implies a 17.8% increase in injury risk. We also found evidence that gender moderates this relationship, where the effect size was twice as large for men than for women (21.8% vs 9.3% per 1 SD decrease). Adult socioeconomic status can explain roughly half of the observed association. Potential explanations for these results are discussed.

Intelligence and neuroticism in relation to depression and psychological distress: Evidence from two large population cohorts

Background

Neuroticism is a risk factor for selected mental and physical illnesses and is inversely associated with intelligence. Intelligence appears to interact with neuroticism and mitigate its detrimental effects on physical health and mortality. However, the inter-relationships of neuroticism and intelligence for major depressive disorder (MDD) and psychological distress has not been well examined.

Methods

Associations and interactions between neuroticism and general intelligence (g) on MDD, self-reported depression, and psychological distress were examined in two population-based cohorts: Generation Scotland: Scottish Family Health Study (GS:SFHS, n = 19,200) and UK Biobank (n = 90,529). The Eysenck Personality Scale Short Form-Revised measured neuroticism and g was extracted from multiple cognitive ability tests in each cohort. Family structure was adjusted for in GS:SFHS.

Results

Neuroticism was strongly associated with increased risk for depression and higher psychological distress in both samples. Although intelligence conferred no consistent independent effects on depression, it did increase the risk for depression across samples once neuroticism was adjusted for. Results suggest that higher intelligence may ameliorate the association between neuroticism and self-reported depression although no significant interaction was found for clinical MDD. Intelligence was inversely associated with psychological distress across cohorts. A small interaction was found across samples such that lower psychological distress associates with higher intelligence and lower neuroticism, although effect sizes were small.

Conclusions

From two large cohort studies, our findings suggest intelligence acts a protective factor in mitigating the effects of neuroticism on psychological distress. Intelligence does not confer protection against diagnosis of depression in those high in neuroticism.

The association between cognitive function and subsequent depression: a systematic review and meta-analysis

Despite a growing interest in understanding the cognitive deficits associated with major depressive disorder (MDD), it is largely unknown whether such deficits exist before disorder onset or how they might influence the severity of subsequent illness. The purpose of the present study was to conduct a systematic review and meta-analysis of longitudinal datasets to determine whether cognitive function acts as a predictor of later MDD diagnosis or change in depression symptoms. Eligible studies included longitudinal designs with baseline measures of cognitive functioning, and later unipolar MDD diagnosis or symptom assessment. The systematic review identified 29 publications, representing 34 unique samples, and 121 749 participants, that met the inclusion/exclusion criteria. Quantitative meta-analysis demonstrated that higher cognitive function was associated with decreased levels of subsequent depression (r = -0.088, 95% confidence interval. -0.121 to -0.054, p < 0.001). However, sensitivity analyses revealed that this association is likely driven by concurrent depression symptoms at the time of cognitive assessment. Our review and meta-analysis indicate that the association between lower cognitive function and later depression is confounded by the presence of contemporaneous depression symptoms at the time of cognitive assessment. Thus, cognitive deficits predicting MDD likely represent deleterious effects of subclinical depression symptoms on performance rather than premorbid risk factors for disorder.

Dietary patterns are associated with cognitive function in the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort

Identifying factors that contribute to the preservation of cognitive function is imperative to maintaining quality of life in advanced years. Of modifiable risk factors, diet quality has emerged as a promising candidate to make an impact on cognition. The objective of this study was to evaluate associations between empirically derived dietary patterns and cognitive function. This study included 18 080 black and white participants aged 45 years and older from the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort. Principal component analysis on data from the Block98 FFQ yielded five dietary patterns: convenience, plant-based, sweets/fats, Southern, and alcohol/salads. Incident cognitive impairment was defined as shifting from intact cognitive status (score >4) at first assessment to impaired cognitive status (score ≤4) at latest assessment, measured by the Six-Item Screener. Learning, memory and executive function were evaluated with the Word List Learning, Word List Delayed Recall, and animal fluency assessments. In fully adjusted models, greater consumption of the alcohol/salads pattern was associated with lower odds of incident cognitive impairment (highest quintile (Q5) v. lowest quintile (Q1): OR 0·68; 95 % CI 0·56, 0·84; P for trend 0·0005). Greater consumption of the alcohol/salads pattern was associated with higher scores on all domain-specific assessments and greater consumption of the plant-based pattern was associated with higher scores in learning and memory. Greater consumption of the Southern pattern was associated with lower scores on each domain-specific assessment (all P < 0·05). In conclusion, dietary patterns including plant-based foods and alcohol intake were associated with higher cognitive scores, and a pattern including fried food and processed meat typical of a Southern diet was associated with lower scores.

Intelligence in youth and mental health at age 50

BACKGROUND

Few cognitive epidemiology studies on mental health have focused on the links between pre-morbid intelligence and self-reports of common mental disorders, such as depression, sleep difficulties, and mental health status. The current study examines these associations in 50-year-old adults.

METHODS

The study uses data from the 5793 participants in the National Longitudinal Survey of Youth 1979 cohort (NLSY-79) who responded to questions on mental health at age 50 and had IQ measured with the Armed Forces Qualification Test (AFQT) when they were aged between 15 and 23 years in 1980. Mental health outcomes were: life-time diagnosis of depression; the mental component score of the 12-item short-form Health Survey (SF-12); the 7-item Center for Epidemiological Studies Depression Scale (CES-D); and a summary measure of sleep difficulty.

RESULTS & CONCLUSION

Higher intelligence in youth is associated with a reduced risk of self-reported mental health problems at age 50, with age-at-first-interview and sex adjusted Bs as follows: CES-depression (B = - 0.16, C.I. - 0.19 to - 0.12, p < 0.001), sleep difficulties (B = - 0.11, C.I. - 0.13 to - 0.08, p < 0.001), and SF-12 mental health status (OR = 0.78, C.I. 0.72 to 0.85, p < 0.001; r = - 0.03 p = 0.075). Conversely, intelligence in youth is linked with an increased risk of receiving a diagnosis of depression by the age of 50 (OR 1.11, C.I. 1.01 to 1.22, p = 0.024; r = 0.03, p = 0.109). No sex differences were observed in the associations. Adjusting for adult SES accounted for most of the association between IQ and the mental health outcomes, except for having reported a diagnosis of depression, in which case adjusting for adult SES led to an increase in the size of the positive association (OR = 1.32, C.I. 1.16 to 1.51, p < 0.001).

Associations Between Childhood Cognition and Cardiovascular Events in Adulthood: A Systematic Review and Meta-analysis

BACKGROUND

The success of behavioural interventions to optimize cardiovascular health is dependent on adequate cognitive functioning beginning in early life. In this study we aimed to systematically review studies that examined associations between childhood cognition and cardiovascular disease (CVD) events in adulthood.

METHODS

This study followed the Meta-analysis Of Observational Studies in Epidemiology guidelines to systematically examine associations between childhood cognition and adult CVD, coronary heart disease, and stroke hospitalization or mortality events. Literature was retrieved from EMBASE, MEDLINE, PsycInfo, and CINAHL.

RESULTS

Five longitudinal studies that examined links between childhood cognition and CVD in adulthood were included. Pooled estimates of unadjusted CVD events indicated a relative risk of 1.23 (95% confidence interval, 1.12-1.34) per standard deviation decrease in childhood IQ, whereas the pooled estimate adjusted for biopsychosocial confounding factors indicated an overall relative risk of 1.16 (95% confidence interval, 1.07-1.26).

CONCLUSIONS

Lower childhood IQ is associated with an increased risk of cardiovascular events in adulthood, even after adjustment for confounding variables. Future research should examine the behavioural mechanisms by which these risks are mediated to optimize cardiovascular health.