Whilst the syndrome approach to schizotypy has recently demonstrated differential correlates of a three-factor model of schizotypal personality, variations in the nature of these factors question a basic assumption of this approach. This... more
Whilst the syndrome approach to schizotypy has recently demonstrated differential correlates of a three-factor model of schizotypal personality, variations in the nature of these factors question a basic assumption of this approach. This study tested competing models of the factor structure of schizotypal personality using the Schizotypal Personality Questionnaire (SPQ) in a sample of 1,201 Mauritians. Factor invariance across gender,
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Emotional support from family and friends is associated with lower psychological distress. This study examined whether genetic and environmental influences explain associations among family support, friend support, and psychological... more
Emotional support from family and friends is associated with lower psychological distress. This study examined whether genetic and environmental influences explain associations among family support, friend support, and psychological distress. Data were drawn from the Midlife Development in the United States (MIDUS) study and included 947 pairs of MZ, same-sex DZ, and opposite-sex DZ twins. Results showed that a genetic factor explains the relationship between friend support and psychological distress, independent of family support. Alternatively, a nonshared environmental factor accounts for an association among family support, friend support, and psychological distress. Thus, heritable factors shape a distinct relationship between friend support and psychological distress, but unique experiences contribute to a link among family support, friend support, and psychological distress.
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Although the negative consequences on health of being obese are well known, most adults gain weight across the lifespan. The general increase in body mass index (BMI) is mainly considered to originate from behavioral and environmental... more
Although the negative consequences on health of being obese are well known, most adults gain weight across the lifespan. The general increase in body mass index (BMI) is mainly considered to originate from behavioral and environmental changes; however, few studies have evaluated the influence of these factors on change in BMI in the presence of genetic risk. We aimed to study the influence of multifactorial causes of change in BMI, over 65 years. Totally, 6130 participants from TwinGene, who had up to five assessments, and 536 from the Swedish Adoption/Twin Study of Aging, who had up to 12 assessments, ranging over 65 years were included. The influence of lifestyle factors, birth cohort, cardiometabolic diseases and an individual obesity genetic risk score (OGRS) based on 32 single nucleotide polymorphisms on change in BMI was evaluated with a growth model. For both sexes, BMI increased from early adulthood to age of 65 years, after which the increase leveled off; BMI declined after...
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few studies have examined associations of multi-faceted demographic, health and lifestyle factors with long-term change in grip strength performance across the adult lifespan. The aim of this study was to examine the associations of risk... more
few studies have examined associations of multi-faceted demographic, health and lifestyle factors with long-term change in grip strength performance across the adult lifespan. The aim of this study was to examine the associations of risk factors in specific parts of the adult lifespan (e.g. in early midlife, in late midlife and in old adulthood) separately for women and men. data came from the longitudinal Swedish Adoption/Twin Study of Aging (SATSA). Grip strength performance was followed in 849 participants who were 50-88 years of age at baseline. The follow-up period with seven waves of data of grip strength was 22 years, and the risk factors were measured up to 20 years before the assessment of grip strength. Latent growth modelling was used for the longitudinal analyses. a gender difference in the type of factors associated with grip strength performance and development across the adult lifespan was found. Significant factors for the age slopes for women were stress, smoking and dementia. For men, marital status, mean arterial pressure, physical activity at work and having a chronic disorder were of importance. These factors varied in their associations with grip strength across the adult lifespan. factors measured earlier in adulthood were associated with grip strength decline in late midlife and old adulthood. Gender-specific patterns of risk factors suggest that it may be worthwhile to conduct research on grip and muscle strength (and biological vitality) separately for men and women.
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Longitudinal data for height (length) between birth and 2 years of age were examined for 690 Dutch Registry twin pairs. A two-stage analysis was performed, where individual growth curves were first fit to available data for each subject... more
Longitudinal data for height (length) between birth and 2 years of age were examined for 690 Dutch Registry twin pairs. A two-stage analysis was performed, where individual growth curves were first fit to available data for each subject using a linear multiple regression procedure and estimated individual growth curve parameters were then subjected to multivariate biometrical analysis. Quadratic polynomial curves
Research Interests: Genetics, Psychology, Developmental Psychology, Statistics, Genomics, and 21 moreAnthropometry, Behavior Genetics, Humans, Female, Male, Infant, Netherlands, Individual variation, Registries, Multiple Regression, Newborn Infant, Longitudinal Studies, Biometrical Analysis, Longitudinal data, Growth curves, Body Weight, Genetic variation, Gestational Age, Body Height, Neurosciences, and Growth Curve
Research Interests: Genetics, Psychology, Cognitive Science, Developmental Psychology, Genomics, and 17 moreLife Style, Adolescent, Development, Antisocial Personality Disorder, Affect, Child Behavior, Humans, Child, Female, Male, Heart rate, Mental Disorders, Longitudinal Studies, Rest, Antisocial Behavior, Adolescent Behavior, and Environment
Previous studies have repeatedly shown verbal intelligence deficits in adolescent antisocial individuals, but it is not known whether these deficits are in place prior to kindergarten or, alternatively, whether they are acquired... more
Previous studies have repeatedly shown verbal intelligence deficits in adolescent antisocial individuals, but it is not known whether these deficits are in place prior to kindergarten or, alternatively, whether they are acquired throughout childhood. This study assesses whether cognitive deficits occur as early as age 3 years and whether they are specific to persistently antisocial individuals. Verbal and spatial abilities
Research Interests: Psychology, Cognitive Science, Intelligence, Personality Assessment, Adolescent, and 16 moreDevelopment, Antisocial Personality Disorder, Space perception, Right Hemisphere Functions, Humans, Child, Mauritius, Spatial ability, Female, Male, Verbal behavior, Risk factors, Longitudinal Studies, Antisocial Behavior, Risk Factors, and Cognition disorders
Physical activity is associated with various health-relevant psychosocial and physiological processes, but activity stability across extended time periods is inadequately understood. This lifespan longitudinal cohort study examined... more
Physical activity is associated with various health-relevant psychosocial and physiological processes, but activity stability across extended time periods is inadequately understood. This lifespan longitudinal cohort study examined activity levels of 723 males and 554 females. Associations across time were computed and structural equation modeling compared a one factor model and a simplex model. Results showed activity levels are somewhat stable from childhood through middle and late adulthood. Further, a simplex model provided a better fit than a one factor model. Successful models and interventions to improve health will likely require a more nuanced, pattern-sensitive understanding of physical activity across time.
Research Interests: Psychology, Cognitive Science, Health Psychology, Aging, Physical Activity, and 18 moreHealth, Adolescent, Child Behavior, Humans, Child, Female, Male, Gender Difference, Cohort Study, Young Adult, Exercise, Structural Equation Model, Aged, Middle Aged, Longitudinal Studies, Adult, Curriculum and Pedagogy, and Five Factor Model
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Research Interests: Psychiatry, Adoption, Sweden, Humans, Female, and 6 moreMale, Social Environment, Aged, Middle Aged, Monoamine oxidase, and Cohort Studies
The purpose of this report is to describe the Study of Dementia in Swedish Twins (known as HARMONY), including procedures for complete ascertainment of all cases of... more
The purpose of this report is to describe the Study of Dementia in Swedish Twins (known as HARMONY), including procedures for complete ascertainment of all cases of Alzheimer's disease (AD) and other dementias in 14,435 individuals aged 65 and older from the national Swedish twin registry. Telephone cognitive screening identified 11.5% as positive for cognitive dysfunction. Clinical diagnoses were completed for 1557 individuals, including individuals who screened positive, their twin partners, and a sample of normal controls. Estimated prevalence of dementia ranged from 1.4% for age 65-69 to 29.2% for age 90 and older. Concordance rates for Alzheimer's disease were 59% for monozygotic twins, 32% for like-sexed, and 24% for unlike-sexed dizygotic twins. Among monozygotic twins where both twins had Alzheimer's disease, the within pair difference in age of onset ranged from both becoming demented in the same year to 7 years difference in onset.
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Research Interests: Marketing, Psychology, Cognitive Science, Intelligence, Cognition, and 16 moreChild Development, Reading, Child Behavior, Prospective studies, Humans, Child, Personality Development, Female, Achievement, Male, Ethnic Groups, Journal of Personality and Social Psychology, Longitudinal Studies, Sex Factors, Longitudinal Study, and Intelligence tests
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Research Interests: Genetics, Psychology, Cognitive Science, Anxiety Disorders, Family, and 23 moreAdolescent, Comorbidity, Humans, Child, Female, Male, Child and Adolescent Psychology, Human Behavioral Genetics, Depressive Disorder, Mental Disorders, Conduct Disorder, Social Environment, Risk factors, Clinical Sciences, Parents, Longitudinal Studies, Virginia, Behavior Problems, Health surveys, Twin Study, Risk Factors, Cross Sectional Studies, and Cohort Studies
ABSTRACT
The Center for Epidemiological Studies Depression scale (CES-D) was administered in Swedish to two representative samples, one aged 84 to 90 (mean = 87), the second aged 29 to 95 (mean = 61). There were both linear and quadratic... more
The Center for Epidemiological Studies Depression scale (CES-D) was administered in Swedish to two representative samples, one aged 84 to 90 (mean = 87), the second aged 29 to 95 (mean = 61). There were both linear and quadratic differences with age: the oldest individuals were highest on depressive symptoms, but younger adults were higher than middle-aged. Dimensions or subscales identified by previous studies were generally replicated, including a sadness and depressed mood factor, a psychomotor retardation and loss of energy factor, and a well-being factor (on which items are reverse-scored to indicate depression). The findings support cross-national use of the CES-D to assess self-reported symptoms of depression in adults and older adults.
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Most genetic sequence variants that contribute to variability in complex human traits will have small effects that are not readily detectable with population samples typically used in genetic association studies. A potentially valuable... more
Most genetic sequence variants that contribute to variability in complex human traits will have small effects that are not readily detectable with population samples typically used in genetic association studies. A potentially valuable tool in the gene discovery process is meta-analysis of the accumulated published data, but in order to be valid these require a sample of studies representative of the true genetic effect and thus hypothetically should include some positive and an abundance of negative reports. A survey of the literature on association studies for Alzheimer disease (AD) from January 2004-April 2005, identified 138 studies, 86 of which reported positive findings other than for apolipoprotein E (APOE), strongly indicative of publication bias. We report here an analysis of 62 genetic markers, tested for association with AD risk as well as for possible effects upon quantitative indices of AD severity (mini-mental state examination scores, age-at-onset, and cerebrospinal fluid (CSF) beta-amyloid (Abeta) and CSF tau proteins). Within this set, only modest signals were present that, with the exception of APOE are easily lost when corrections for multiple hypotheses are applied. In isolation, results are thus broadly negative. Genes studied encompass both novel candidates as well as several recently claimed to be associated with AD (e.g. urokinase plasminogen activator (PLAU) and acetyl-coenzyme A acetyltransferase 1 (ACAT1)). By reporting these data we hope to encourage the publication of gene compendia to guide further studies and aid future meta-analyses aimed at resolving the involvement of genes in complex human traits.
Research Interests: Genetics, Human Genetics, Complementary and Alternative Medicine, Association study, Cerebrospinal Fluid, and 15 moreHumans, Female, Male, Risk factors, Meta Analysis, Publication Bias, Mini Mental State Examination, Aged, Middle Aged, Genotype, Analysis of Variance, Risk Factors, Genetic Association, Alzheimer Disease, and Age at Onset
Sleep duration is known to significantly affect health in adults and children, but little is understood about long-term associations. This prospective cohort study is the first to examine whether childhood sleep duration is associated... more
Sleep duration is known to significantly affect health in adults and children, but little is understood about long-term associations. This prospective cohort study is the first to examine whether childhood sleep duration is associated with lifelong mortality risk. Data from childhood were refined and mortality data collected for 1,145 participants from the Terman Life Cycle Study. Participants were born between 1904 and 1915, lived to at least 1940, and had complete age, bedtime, and waketime data at initial data collection (1917-1926). Homogeneity of the cohort sample (intelligent, mostly White) limits generality but provides natural control of common confounds. Through 2009, 1,039 participants had confirmed deaths. Sleep duration was calculated as the difference between each child's bed and wake times. Age-adjusted sleep (deviation from that predicted by age) was computed. Cox proportional hazards survival models evaluated childhood sleep duration as a predictor of mortality separately by sex, controlling for baseline age. For males, a quadratic relation emerged: Male children who underslept or overslept compared with peers were at increased risk of lifelong all-cause mortality (HR = 1.15, CIs [1.05, 1.27]). Effect sizes were smaller and nonsignificant in females (HR = 1.02, CIs [0.91, 1.14]). Male children with shorter or longer sleep durations than expected for their age were at increased risk of death at any given age in adulthood. The findings suggest that sleep may be a core biobehavioral trait, with implications for new models of sleep and health throughout the entire life span.
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Research Interests: Genetics, Psychology, Cognitive Science, Developmental Psychology, Genomics, and 17 moreLife Style, Adolescent, Development, Antisocial Personality Disorder, Affect, Child Behavior, Humans, Child, Female, Male, Heart rate, Mental Disorders, Longitudinal Studies, Rest, Antisocial Behavior, Adolescent Behavior, and Environment
Research Interests: Genetics, Psychology, Developmental Psychology, Statistics, Genomics, and 21 moreAnthropometry, Behavior Genetics, Humans, Female, Male, Infant, Netherlands, Individual variation, Registries, Multiple Regression, Newborn Infant, Longitudinal Studies, Biometrical Analysis, Longitudinal data, Growth curves, Body Weight, Genetic variation, Gestational Age, Body Height, Neurosciences, and Growth Curve
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Research Interests:
The current study investigated age differences and longitudinal change in mode effects, wherein individuals report less negative and more positive psychosocial functioning with data collection modes that have greater (vs. less) direct... more
The current study investigated age differences and longitudinal change in mode effects, wherein individuals report less negative and more positive psychosocial functioning with data collection modes that have greater (vs. less) direct contact with interviewers (e.g., in-person interviews vs. telephone interviews). Using 2 longitudinal datasets, the Later Life Study of Social Exchanges (LLSSE) and Swedish Adoption/Twin Study of Aging (SATSA), we tested how mode effects may vary with cohort (baseline age differences) and maturational development (longitudinal change). In Study 1, LLSSE participants (65-90 years old) completed in-person and telephone interviews assessing negative and positive aspects of psychosocial functioning across 2 years. The data collection mode with greater direct contact with interviewers (in-person interviews) was associated with reporting less negative and more positive psychosocial functioning compared to the mode with less direct contact (telephone interviews). These mode effects were more pronounced with older baseline age, but only for the negative psychosocial measures. Mode effects also became stronger over time for reports of negative affect. In Study 2, SATSA participants (38-86 years old) completed mailed questionnaires and questionnaires collected in-person that assessed depressive symptoms and positive affect across 18 years. Consistent with Study 1, participants reported fewer depressive symptoms and more positive affect with greater (vs. less) direct contact with interviewers (questionnaires collected in-person vs. mailed questionnaires). For reports of depressive symptoms, but not positive affect, mode effects were more pronounced with age and time. Together, the results underscore how mode effects may contribute to inconsistent findings in the socioemotional aging literature. (PsycINFO Database Record
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This study tested for differential patterns of cognitive decline in 33 twin pairs for which both were nondemented, but 1 member of the pair went on to develop dementia. Compared with their nondemented twin partners, twins who later... more
This study tested for differential patterns of cognitive decline in 33 twin pairs for which both were nondemented, but 1 member of the pair went on to develop dementia. Compared with their nondemented twin partners, twins who later developed dementia already showed poorer performance on tests of memory and attention, visuospa- tial-reasoning skills, and perceptual speed and the Mini-Mental State
Research Interests: Sociology, Psychology, Psychometrics, Risk assessment, Sweden, and 16 moreHumans, Female, Male, Cognitive Process, Clinical Sciences, Mini Mental State Examination, Aged, Middle Aged, Reproducibility of Results, Twin Study, Geriatric Assessment, Risk Assessment, Cognitive Decline, Reference Values, Alzheimer Disease, and Cognition disorders
To investigate how apolipoprotein E (APOE) affects the temporal relationship between depression and dementia, we conducted a nested case-control study with longitudinal depression and dementia evaluations from several population studies... more
To investigate how apolipoprotein E (APOE) affects the temporal relationship between depression and dementia, we conducted a nested case-control study with longitudinal depression and dementia evaluations from several population studies by using 804 dementia cases and 1600 matched controls, totaling 1519 unique individuals. Depression within 10 years of onset of dementia was strongly associated with dementia diagnosis regardless of APOE status (incidence rate ratio [IRR] 5.25, 95% confidence interval [95% CI] 3.32-8.31 for ε4 carriers, IRR 4.40, 95%CI 3.23-5.99 for noncarriers). However, we found a significant interaction between depression more than 10 years before the onset of dementia and APOE (p = 0.01), with depression more distal to dementia being a risk factor only in ε4 carriers (IRR 3.39, 95% CI 1.69-6.78 for carriers, IRR 1.01, 95% CI 0.60-1.70 for noncarriers). Thus, depression with onset close in time to dementia onset is associated with disease irrespective of APOE genotype, whereas depression more distal to dementia onset is a risk factor only in ε4-carriers. This is the first study to show the interaction between APOE and depression to be dependent on timing of depression onset.
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Research Interests: Genetics, Physiology, Dementia, Sweden, Biological Sciences, and 16 moreHumans, Female, Male, Apolipoprotein E, Risk factors, Registries, Aged, Longitudinal Studies, Clinical Assessment, Educational Status, Twin Study, Risk Factors, Environment, Confidence Interval, Case Control Studies, and Cohort Studies
Though many cognitive abilities exhibit marked decline over the adult years, individual differences in rates of change have been observed. In the current study, biometrical latent growth models were used to examine sources of variability... more
Though many cognitive abilities exhibit marked decline over the adult years, individual differences in rates of change have been observed. In the current study, biometrical latent growth models were used to examine sources of variability for ability level (intercept) and change (linear and quadratic effects) for verbal, fluid, memory, and perceptual speed abilities in the Swedish Adoption/Twin Study of Aging.
Research Interests: Genetics, Psychology, Cognitive Science, Developmental Psychology, Cognition, and 17 moreAdoption, Aging, Quantitative Genetics, Sweden, Memory, Humans, Female, Male, Developmental, Aged, Middle Aged, Cognitive Ability, Twin Study, Individual Difference, Growth Model, Environment, and Cognition disorders
Latent growth models were applied to data from the Swedish Adoption/Twin Study of Aging to discover if the rate of change in cognitive performance increased from middle age to later adulthood. The sample included 590 participants aged 44... more
Latent growth models were applied to data from the Swedish Adoption/Twin Study of Aging to discover if the rate of change in cognitive performance increased from middle age to later adulthood. The sample included 590 participants aged 44 to 88 years at first measurement. Data were gathered at 2 follow-up occasions at intervals of 3 years. Cognitive ability was assessed
Research Interests: Psychology, Cognitive Science, Developmental Psychology, Psychometrics, Individuality, and 23 moreCognition, Adoption, Aging, Twins, Humans, Spatial ability, Female, Male, Gender Difference, Reaction Time, Aptitude, Social Environment, Developmental, Cognitive Performance, Aged, Middle Aged, Adult, Sex Factors, Cognitive Ability, Twin Study, Reference Values, Growth Model, and Growth Curve
Researchers studying the prevalence and characteristics of Alzheimer's disease and other dementias must rely on broad screening of large representative commu-nity samples followed by diagnostic examination of those who score... more
Researchers studying the prevalence and characteristics of Alzheimer's disease and other dementias must rely on broad screening of large representative commu-nity samples followed by diagnostic examination of those who score positively for cognitive impairment. Although it is ...
Research Interests:
Goals of the present study were to investigate the relationship between age changes in speed and cognition and the genetic and environmental influences on that relationship. Latent growth models and quantitative genetic methods were... more
Goals of the present study were to investigate the relationship between age changes in speed and cognition and the genetic and environmental influences on that relationship. Latent growth models and quantitative genetic methods were applied to data from the Swedish Adoption/Twin Study of Aging. The sample included 778 individuals from both complete and incomplete twin pairs who participated in at
Research Interests: Genetics, Psychology, Spatial Memory, Cognition, Aging, and 26 moreBehavior Genetics, Quantitative Genetics, Cognitive Aging, Multivariate Analysis, Twins, Space perception, Processing Speed, Thinking, Humans, Female, Male, Verbal behavior, Registries, Cognitive Performance, Aged, Middle Aged, Longitudinal Studies, Time Factors, Cognitive Ability, Twin Study, Genetic variation, Reference Values, Growth Model, Environment, Neurosciences, and Growth Curve
few studies have examined associations of multi-faceted demographic, health and lifestyle factors with long-term change in grip strength performance across the adult lifespan. The aim of this study was to examine the associations of risk... more
few studies have examined associations of multi-faceted demographic, health and lifestyle factors with long-term change in grip strength performance across the adult lifespan. The aim of this study was to examine the associations of risk factors in specific parts of the adult lifespan (e.g. in early midlife, in late midlife and in old adulthood) separately for women and men. data came from the longitudinal Swedish Adoption/Twin Study of Aging (SATSA). Grip strength performance was followed in 849 participants who were 50-88 years of age at baseline. The follow-up period with seven waves of data of grip strength was 22 years, and the risk factors were measured up to 20 years before the assessment of grip strength. Latent growth modelling was used for the longitudinal analyses. a gender difference in the type of factors associated with grip strength performance and development across the adult lifespan was found. Significant factors for the age slopes for women were stress, smoking and dementia. For men, marital status, mean arterial pressure, physical activity at work and having a chronic disorder were of importance. These factors varied in their associations with grip strength across the adult lifespan. factors measured earlier in adulthood were associated with grip strength decline in late midlife and old adulthood. Gender-specific patterns of risk factors suggest that it may be worthwhile to conduct research on grip and muscle strength (and biological vitality) separately for men and women.
Research Interests:
Research Interests:
We investigated the extent to which cognitive dysfunction is shaped by genetic or environmental influences, and whether these factors differ in women and men. All members of the Swedish Twin Registry aged 65 and older were screened by... more
We investigated the extent to which cognitive dysfunction is shaped by genetic or environmental influences, and whether these factors differ in women and men. All members of the Swedish Twin Registry aged 65 and older were screened by telephone using the TELE, a brief cognitive assessment instrument (Gatz et al., 2002), and the Blessed Dementia Rating Scale (Blessed et al., 1968) from relatives of those who scored poorly on the TELE. Data were available for 4308 pairs where both members responded and 5070 pairs where only one member was alive and participated. To analyze all available data, we used a raw data method extended to ordinal data. As the prevalence of cognitive dysfunction increases with age, we incorporated age-adjusted thresholds. The best fitting model from biometric analyses indicated 35% of the variation in liability to cognitive dysfunction could be explained by heritable influences and the remaining 65% by nonfamilial environmental influences. Differences by gender were not significant. As this is a normative population including cognitively intact individuals, preclinical dementia cases and demented individuals, the relative magnitude of genetic and environmental effects is of particular interest in light of high heritabilities found for dementias such as Alzheimer's disease. The findings emphasize the extent to which research is needed to uncover nonfamilial environmental influences on cognitive dysfunction in later life.
Research Interests:
Research Interests: Psychometrics, Schizophrenia, Adolescent, Humans, Personality Assessment Inventory, and 16 moreFemale, Confirmatory factor analysis, Male, Mathematical Computing, Interpersonal Relations, Null Model, Computer Program, Schizotypal Personality Disorder, Aged, Middle Aged, Adult, Five Factor Model, Individual Difference, Reference Values, General Population, and Cognition disorders
What are the best quantitative methods for studying cognitive decline? This question was investigated in a sample of 638 individuals aged 50 years and older from the Swedish Adoption/Twin Study of Aging. A battery of cognitive tests... more
What are the best quantitative methods for studying cognitive decline? This question was investigated in a sample of 638 individuals aged 50 years and older from the Swedish Adoption/Twin Study of Aging. A battery of cognitive tests tapping multiple domains was administered to each individual from 2 to 7 times over a span of 10 years. Four methods of operationalizing cognitive decline were compared: change scores, a criterion-based method, least squares, and random effects regression (RER). The RER results were most consistent with a significant decline across measures and differences between demented and nondemented individuals. Predicted slopes from the RER model also showed the strongest interrelationships within and across cognitive domains as indicated by factor analysis results and stronger associations with demographic, health, and psychosocial predictors.
Research Interests: Psychology, Cognitive Science, Demography, Psychometrics, Forecasting, and 17 moreSocial Support, Factor analysis, Humans, Female, Male, Individual variation, Health Status, Aged, Middle Aged, Adult, Random-Effects Models, Reproducibility of Results, Twin Study, Psychology of Aging, Cognitive Decline, Quantitative Method, and Cognition disorders
Research Interests: Psychology, Cognitive Science, Anxiety Disorders, Individuality, Adolescent, and 21 moreHumans, Child, Europe, Psychological, United States, Female, Male, Young Adult, Follow-up studies, Depressive Disorder, Social Environment, Registries, Aged, Middle Aged, Questionnaires, Longitudinal Studies, Adult, Analysis of Variance, Age Factors, Psychological Science, and Life Change Events
The possibility of genotype-environment interaction for memory performance and change was examined in 150 monozygotic (MZ) twin pairs from the Swedish Adoption Twin Study of Aging (SATSA). We used an MZ twin pair difference approach to... more
The possibility of genotype-environment interaction for memory performance and change was examined in 150 monozygotic (MZ) twin pairs from the Swedish Adoption Twin Study of Aging (SATSA). We used an MZ twin pair difference approach to examine the possibility that genotype was associated with intrapair variability and thus suggestive of genotype-nonshared environment interactions. Multiple 'variability genes' were found for longitudinal change in a semantic memory task including candidates coding for apolipoprotein E (APOE) and estrogen receptor alpha (ESR1) as well as serotonin candidates (HTR2A and 5HTT). One candidate also related to variability in change in episodic memory (5HTT). Of the significant associations observed, generally results indicated that MZ pairs who carry putative risk alleles were less variable than noncarriers, suggesting that noncarriers may be more sensitive to environmental contexts. We sought to 'contextualize' the possible nonshared environmental influences for found gene-environment (G x E) effects by considering intrapair differences in measured social and stress factors, including social support, life events and depressive symptoms. Results suggested that nonshared environmental influences associated with depressive symptoms may moderate the G x E relationship observed for ESR1 and APOE and longitudinal semantic memory change whereby noncarriers of putative risk alleles may be relatively more sensitive to depressionevoking environmental contexts than carriers of the risk allele. Thus, the contexts that facilitate or reduce depressive symptoms may affect semantic memory resiliency dependent on genotype. Further work ought to consider larger sample sizes as well as consider additional social and contextual factors.
Research Interests: Cognitive Science, Depression, Cognition, Aging, Social Support, and 15 moreCognitive Aging, Memory, Humans, Female, Male, Human Behavioral Genetics, Genotype X Environment Interaction, Social Environment, Clinical Sciences, Aged, Genotype, Physiological Stress Markers, Social Factor, Twin, and Life Change Events
Research Interests: Genetics, Cognitive Science, Dementia, Risk, Neurogenetics, and 14 moreSweden, Cerebrospinal Fluid, Humans, Haplotypes, Meta Analysis, Membrane transport proteins, Linkage Disequilibrium, Quantitative Trait Loci, Genetic variation, Alzheimer Disease, Genetic Markers, Neurosciences, Confidence Interval, and Age at Onset
We present a fresh approach to evaluating association with candidate genes and cognitive change by testing association for parameters describing individual growth curves from twins. Moderate genetic influences on memory in aging adults... more
We present a fresh approach to evaluating association with candidate genes and cognitive change by testing association for parameters describing individual growth curves from twins. Moderate genetic influences on memory in aging adults has been shown in quantitative genetic studies. A recently reported, association of a HTR2A polymorphism with episodic memory in young unrelated adults led us to investigate the association between a nearby polymorphism and longitudinal memory performance in the Swedish Adoption/Twin Study of Aging (SATSA). Analysis of growth curve parameters suggests that both how well individuals perform on figural memory at age 65 years and nonlinear change in figural memory performance across age are associated with HTR2A. Individuals with two copies of the common G allele demonstrated higher figural memory performance longitudinally than those with the less frequent A allele, with performance trajectories differing by 2-6% per year. These findings imply a role for the 5-HT2A serotonin receptor on the formation of episodic memories in older adults.