Assessing structural models of neighborhood and family sociodemographic characteristics and their relations with externalizing psychopathology.

Externalizing psychopathology has been found to have small to moderate associations with neighborhood and family sociodemographic characteristics. However, prior studies may have used suboptimal operationalizations of neighborhood sociodemographic characteristics and externalizing psychopathology, potentially misestimating relations between these constructs. To address these limitations, in the current study we test different measurement models of these constructs and assess the structural relations between them. Using a population-representative sample of 2,195 twins and siblings from the Georgia Twin Study and data from the National Neighborhood Data Archive and 2000 U.S. Census, we assessed the fit of competing measurement models for family sociodemographic, neighborhood sociodemographic, and neighborhood environment characteristics. In structural models, we regressed a general externalizing dimension on different operationalizations of these variables separately and then simultaneously in a final model. Latent variable operationalizations of family sociodemographic, neighborhood sociodemographic, and neighborhood environment characteristics explained no more variance in broad externalizing psychopathology than other operationalizations. In an omnibus model, family sociodemographic characteristics showed a small association with externalizing psychopathology, while neighborhood sociodemographic and environmental characteristics did not. Family sociodemographic characteristics showed small associations with neighborhood sociodemographic and environmental characteristics, and neighborhood sociodemographic characteristics were moderately associated with neighborhood environment. These findings suggest that family sociodemographic characteristics are more associated with the development of broad externalizing psychopathology in youth than neighborhood sociodemographic characteristics and neighborhood environment. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Two babies, two bonds: Frequency and correlates of differential maternal-infant bonding in mothers of twins.

We assessed prevalence and correlates of differential maternal-infant bonding (i.e., experiencing a stronger bond with one baby vs. the other) in mothers of twins, focusing on aspects of maternal mental health, well-being, and pregnancy/birth that have been previously linked with maternal-infant bonding. Participants (N = 108 American women, 88.89% White, 82.41% non-Hispanic, aged 18-45, who gave birth to twins in the past 6-24 weeks) were recruited from postpartum support websites. Participants completed a Qualtrics survey assessing pregnancy/birth history, symptoms of depression and anxiety, sleep, stress, romantic relationship satisfaction, and postpartum bonding. Twenty-six participants (24.07%) reported a bonding discrepancy. These participants endorsed higher symptoms of depression and anxiety, lower relationship satisfaction, lower average postpartum bonding, higher general and parenting stress, and longer pregnancy (all ps > .05). Greater degree of bonding discrepancy correlated with more depression, higher parenting stress, longer pregnancy, and lower relationship satisfaction (all ps > .05). Mothers of twins may benefit from postpartum mental health support, stress management strategies, and interventions to improve bonding. Future work should assess the role of breastfeeding difficulties, delivery method, birth-related trauma, infant regulatory capacity, and temperament. Longitudinal studies will help test cause and effect and potential long-term repercussions of maternal-infant bonding discrepancies.

Evaluamos la prevalencia y factores correlacionados del apego afectivo diferencial materno­infantil (v.g. experimentar un apego más fuerte con un bebé vs. el otro) en madres de gemelos, enfocándonos en aspectos de salud mental materna, bienestar, así como el embarazo/parto que previamente han sido relacionadas con la afectividad materno­infantil. A las participantes (N = 108 mujeres estadounidenses, 88.89% blancas, 82.41% no hispanas, de 18­45 años, que dieron a luz gemelos en las pasadas 6­24 semanas) se les reclutó de los sitios de apoyo posterior al parto en la red. Las participantes completaron una encuesta Qualtrics para evaluar el historial de embarazo/parto, los síntomas de depresión y ansiedad, el sueño, el estrés, la satisfacción con la relación romántica, así como la afectividad posterior al parto. Veintiséis participantes (24.07%) reportaron discrepancia en el apego afectivo. Estas participantes confirmaron síntomas más altos de depresión y ansiedad, más baja satisfacción en la relación, más bajo promedio de apego afectivo posterior al parto, más alto estrés general y de crianza, así como un más largo embarazo (todos los ps > .05). Un mayor grado de discrepancia en el apego afectivo se relacionó con más depresión, un más alto estrés de crianza, un más largo embarazo, así como una más baja satisfacción en la relación (todos los ps > .05). Las madres de gemelos pudieran beneficiarse de un apoyo de salud mental posterior al parto, estrategias de cómo arreglárselas con el estrés e intervenciones para mejorar el apego afectivo. El trabajo futuro debe evaluar el papel de las dificultades de amamantar, el método usado para dar a luz, el trauma relacionado con el nacimiento, la capacidad regulatoria del infante y el temperamento. Estudios longitudinales ayudarán a poner a prueba la causa y el efecto las potenciales repercusiones a largo plazo de las discrepancias en el apego afectivo materno­infantil.

Nous avons évalué la prévalence et les corrélats du lien maternel­bébé différentiel (c'est­à­dire qui font l'expérience d'un lien plus fort avec un bébé par rapport à l'autre) chez les mères de jumeaux ou jumelles, en mettant l'accent sur les aspects de la santé mentale maternelle, le bien­être et la grossesse/naissance ayant précédemment été liés au lien maternel­bébé. Les participantes (N = 108 femmes américaines, 88,89% blanches, 82,41% non­latinas, âgées de 18­45 ans, ayant donné naissance à des jumeaux ou jumelles dans les 6­24 semaines précédentes) ont été recrutées à partir de sites internet de soutien postpartum. Les participantes ont rempli un questionnaire Qualtrics évaluant la grossesse/l'histoire de la naissance, les symptômes de dépression et d'anxiété, le sommeil, le stress, la satisfaction de la relation amoureuse et le lien postpartum. Vingt­six participantes (24,07%) ont fait état d'un écart du lien. Ces participantes ont fait état de plus de symptômes de dépression et d'anxiété, d'une satisfaction avec la relation plus basse, d'un lien postpartum plus bas en moyenne, d'un stress général et parental plus élevé, et d'une grossesse plus longue (tout ps >,05). Un degré plus élevé d'écart du lien a correspondu à plus de dépression, un stress de parentage plus élevé, une grossesse plus longue et une satisfaction de la relation plus basse tous ps > ,05). Les mères de jumeaux ou jumelles peut tirer profit d'un soutien en santé mentale postpartum, de stratégies de gestion du stress, et d'interventions pour améliorer le lien. Dans le futur des recherches devraient évaluer le rôle de difficultés de l'allaitement, la méthode d'accouchement, le trauma lié à la naissance, la capacité régulatoire du bébé et son tempérament. Des études longitudinales permettront de tester la cause et l'effet et les répercussions à long terme potentielle pour les écarts dans le lien maternel­bébé.

Reduction in the use of green spaces during the COVID-19 pandemic and its impact on mental health.

Our study examined the use of green spaces before and during the pandemic in a large cohort of Italian twins and evaluated its impact on measures of mental health (depressive, anxiety, stress symptoms). Twins were analysed as individuals and as pairs. A twin design approach was applied to minimize confounding by genetic and shared environmental factors. Questionnaires from 2,473 twins enrolled in the Italian Twin Registry were screened. Reduced green space use was associated with significantly higher levels of depression, anxiety and distress. Being a woman, residing in urban areas, and having a high perceived risk of the outbreak resulted in a higher likelihood to modify green space use, with a negative impact on mental health.

People's desire to be in nature and how they experience it are partially heritable.

Nature experiences have been linked to mental and physical health. Despite the importance of understanding what determines individual variation in nature experience, the role of genes has been overlooked. Here, using a twin design (TwinsUK, number of individuals = 2,306), we investigate the genetic and environmental contributions to a person's nature orientation, opportunity (living in less urbanized areas), and different dimensions of nature experience (frequency and duration of public nature space visits and frequency and duration of garden visits). We estimate moderate heritability of nature orientation (46%) and nature experiences (48% for frequency of public nature space visits, 34% for frequency of garden visits, and 38% for duration of garden visits) and show their genetic components partially overlap. We also find that the environmental influences on nature experiences are moderated by the level of urbanization of the home district. Our study demonstrates genetic contributions to individuals' nature experiences, opening a new dimension for the study of human-nature interactions.

Are there positive effects of having a sibling with special needs? Empathy and prosociality of twins of children with non-typical development.

This study examined whether typically developing (TD) twins of non-TD children demonstrate enhanced empathy and prosociality. Of 778 Hebrew-speaking Israeli families who participated in a twin study, 63 were identified to have a non-TD child with a TD twin, and 404 as having both twins TD. TD twins of non-TD children (27% males) were compared to the rest of the cohort of TD children (46% males) on measures of empathy and prosociality. Participants were 11 years old. TD twins of non-TD children scored significantly higher than TD twins of TD children in a measure of cognitive empathy (d = .43). No differences were found in emotional empathy and prosociality. The specificity of the positive effect on cognitive empathy is discussed.

Childhood maltreatment and disordered gambling in adulthood: disentangling causal and familial influences.

BACKGROUND: Despite abundant research on the potential causal influence of childhood maltreatment (CM) on psychological maladaptation in adulthood, almost none has implemented the discordant twin design as a means of examining the role of such experiences in later disordered gambling (DG) while accounting for genetic and family environmental confounds. The present study implemented such an approach to disentangle the potential causal and familial factors that may account for the association between CM and DG. METHODS: Participants were 3750 twins from the Australian Twin Registry [Mage = 37.60 (s.d. = 2.31); 58% female]. CM and DG were assessed separately via two semi-structured telephone interviews. Random-intercept generalized linear mixed models were fit to the data; zygosity, sex, educational attainment, childhood psychiatric disorder, adult antisocial behavior, and alcohol use disorder (AUD) were included as covariates. RESULTS: Neither quasi-causal nor familial effects of CM predicted DG after adjusting for covariates. Educational attainment appeared to reduce the risk of DG while AUD appeared to increase risk; evidence also emerged for familial effects of antisocial behavior on DG. Post-hoc analyses revealed a familial effect of CM on antisocial behavior, indicating that the association between CM and DG identified in unadjusted models and in prior studies may be accounted for by genetic and shared family environmental effects of antisociality. CONCLUSIONS: These findings add to the meager literature showing that CM does not exert a causal effect on DG, and present novel evidence that familial effects of antisocial behavior may account for the association between CM and DG identified in extant non-twin research.

Parental criticism and adolescent internalising symptoms: using a Children-of-Twins design with power calculations to account for genetic influence.

BACKGROUND: Parental criticism is correlated with internalising symptoms in adolescent offspring. This correlation could in part reflect their genetic relatedness, if the same genes influence behaviours in both parents and offspring. We use a Children-of-Twins design to assess whether parent-reported criticism and offspring internalising symptoms remain associated after controlling for shared genes. To aid interpretation of our results and those of previous Children-of-Twins studies, we examine statistical power for the detection of genetic effects and explore the direction of possible causal effects between generations. METHODS: Data were drawn from two Swedish twin samples, comprising 876 adult twin pairs with adolescent offspring and 1,030 adolescent twin pairs with parents. Parent reports of criticism towards their offspring were collected concurrently with parent and offspring reports of adolescent internalising symptoms. Children-of-Twins structural equation models were used to control for genetic influence on the intergenerational association between parental criticism and adolescent internalising. RESULTS: Parental criticism was associated with adolescent internalising symptoms after controlling for genetic influence. No significant role was found for shared genes influencing phenotypes in both generations, although power analyses suggested that some genetic effects may have gone undetected. Models could not distinguish directionality for nongenetic, causal effects between generations. CONCLUSIONS: Parental criticism may be involved in psychosocial family processes in the context of adolescent internalising. Future studies should seek to identify these processes and provide clarity on the direction of potential causal effects.

Adolescent cannabis use and adult psychoticism: A longitudinal co-twin control analysis using data from two cohorts.

Observational studies have repeatedly linked cannabis use and increased risk of psychosis. We sought to clarify whether this association reflects a causal effect of cannabis exposure or residual confounding. We analyzed data from two cohorts of twins who completed repeated, prospective measures of cannabis use (N = 1544) and cannabis use disorder symptoms (N = 1458) in adolescence and a dimensional measure of psychosis-proneness (the Personality Inventory for DSM-5 Psychoticism scale) in adulthood. Twins also provided molecular genetic data, which were used to estimate polygenic risk of schizophrenia. Both cumulative adolescent cannabis use and use disorder were associated with higher Psychoticism scores in adulthood. However, we found no evidence of an effect of cannabis on Psychoticism or any of its facets in co-twin control models that compared the greater-cannabis-using twin to the lesser-using co-twin. We also observed no evidence of a differential effect of cannabis on Psychoticism by polygenic risk of schizophrenia. Although cannabis use and disorder are consistently associated with increased risk of psychosis, the present results suggest this association is likely attributable to familial confounds rather than a causal effect of cannabis exposure. Efforts to reduce the prevalence and burden of psychotic illnesses thus may benefit from greater focus on other therapeutic targets. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

On the Genetic and Environmental Relationship Between Suicide Attempt and Death by Suicide.

OBJECTIVE: The authors examined the extent to which the genetic and environmental etiology of suicide attempt and suicide death is shared or unique. METHODS: The authors used Swedish national registry data for a large cohort of twins, full siblings, and half siblings (N=1,314,990) born between 1960 and 1990 and followed through 2015. They conducted twin-family modeling of suicide attempt and suicide death to estimate heritability for each outcome, along with genetic and environmental correlations between them. They further assessed the relationship between suicide attempt by young people compared with adults. RESULTS: In bivariate models, suicide attempt and death were moderately heritable among both women (attempt: additive genetic variance component [A]=0.52, 95% CI=0.44, 0.56; death: A=0.45, 95% CI=0.39, 0.59) and men (attempt: A=0.41, 95% CI=0.38, 0.49; death: A=0.44, 95% CI=0.43, 0.44). The outcomes were substantially, but incompletely, genetically correlated (women: rA=0.67, 95% CI=0.55, 0.67; men: rA=0.74, 95% CI=0.63, 0.87). Environmental correlations were weaker (women: rE=0.36, 95% CI=0.29, 0.45; men: rE=0.21, 95% CI=0.19, 0.27). Heritability of suicide attempt was stronger among people ages 10-24 (A=0.55-0.62) than among those age 25 and older (A=0.36-0.38), and the genetic correlation between attempt during youth and during adulthood was stronger for women (rA=0.79, 95% CI=0.72, 0.79) than for men (rA=0.39, 95% CI=0.26, 0.47). CONCLUSIONS: The genetic and environmental etiologies of suicide attempt and death are partially overlapping, exhibit modest sex differences, and shift across the life course. These differences must be considered when developing prevention efforts and risk prediction algorithms. Where feasible, suicide attempt and death should be considered separately rather than collapsed, including in the context of gene identification efforts.

A Representational Similarity Analysis of Cognitive Control during Color-Word Stroop.

Progress in understanding the neural bases of cognitive control has been supported by the paradigmatic color-word Stroop task, in which a target response (color name) must be selected over a more automatic, yet potentially incongruent, distractor response (word). For this paradigm, models have postulated complementary coding schemes: dorsomedial frontal cortex (DMFC) is proposed to evaluate the demand for control via incongruency-related coding, whereas dorsolateral PFC (DLPFC) is proposed to implement control via goal and target-related coding. Yet, mapping these theorized schemes to measured neural activity within this task has been challenging. Here, we tested for these coding schemes relatively directly, by decomposing an event-related color-word Stroop task via representational similarity analysis. Three neural coding models were fit to the similarity structure of multivoxel patterns of human fMRI activity, acquired from 65 healthy, young-adult males and females. Incongruency coding was predominant in DMFC, whereas both target and incongruency coding were present with indistinguishable strength in DLPFC. In contrast, distractor information was strongly encoded within early visual cortex. Further, these coding schemes were differentially related to behavior: individuals with stronger DLPFC (and lateral posterior parietal cortex) target coding, but weaker DMFC incongruency coding, exhibited less behavioral Stroop interference. These results highlight the utility of the representational similarity analysis framework for investigating neural mechanisms of cognitive control and point to several promising directions to extend the Stroop paradigm.SIGNIFICANCE STATEMENT How the human brain enables cognitive control - the ability to override behavioral habits to pursue internal goals - has been a major focus of neuroscience research. This ability has been frequently investigated by using the Stroop color-word naming task. With the Stroop as a test-bed, many theories have proposed specific neuroanatomical dissociations, in which medial and lateral frontal brain regions underlie cognitive control by encoding distinct types of information. Yet providing a direct confirmation of these claims has been challenging. Here, we demonstrate that representational similarity analysis, which estimates and models the similarity structure of brain activity patterns, can successfully establish the hypothesized functional dissociations within the Stroop task. Representational similarity analysis may provide a useful approach for investigating cognitive control mechanisms.

Network dynamics of momentary affect states and future course of psychopathology in adolescents.

BACKGROUND: Recent theories argue that an interplay between (i.e., network of) experiences, thoughts and affect in daily life may underlie the development of psychopathology. OBJECTIVE: To prospectively examine whether network dynamics of everyday affect states are associated with a future course of psychopathology in adolescents at an increased risk of mental disorders. METHODS: 159 adolescents from the East-Flanders Prospective Twin Study cohort participated in the study. At baseline, their momentary affect states were assessed using the Experience Sampling Method (ESM). The course of psychopathology was operationalized as the change in the Symptom Checklist-90 sum score after 1 year. Two groups were defined: one with a stable level (n = 81) and one with an increasing level (n = 78) of SCL-symptom severity. Group-level network dynamics of momentary positive and negative affect states were compared between groups. RESULTS: The group with increasing symptoms showed a stronger connections between negative affect states and their higher influence on positive states, as well as higher proneness to form 'vicious cycles', compared to the stable group. Based on permutation tests, these differences were not statistically significant. CONCLUSION: Although not statistically significant, some qualitative differences were observed between the networks of the two groups. More studies are needed to determine the value of momentary affect networks for predicting the course of psychopathology.

Genetic and environmental architecture of conscientiousness in adolescence.

Using a genetically informative design (about 2000 twin pairs), we investigated the phenotypic and genetic and environmental architecture of a broad construct of conscientiousness (including conscientiousness per se, effortful control, self-control, and grit). These four different measures were substantially correlated; the coefficients ranged from 0.74 (0.72-0.76) to 0.79 (0.76-0.80). Univariate genetic analyses revealed that individual differences in conscientiousness measures were moderately attributable to additive genetic factors, to an extent ranging from 62 (58-65) to 64% (61-67%); we obtained no evidence that shared environmental influences were observed. Multivariate genetic analyses showed that for the four measures used to assess conscientiousness, genetic correlations were stronger than the corresponding non-shared environmental correlations, and that a latent common factor accounted for over 84% of the genetic variance. Our findings suggest that individual differences in the four measures of conscientiousness are not distinguishable at both the phenotypic and behavioural genetic levels, and that the overlap was substantially attributable to genetic factors.

General Cognitive Abilities and Psychosocial Development in Children and Adolescents Having a Co-Twin with Down Syndrome.

OBJECTIVE: To examine the general cognitive and psychosocial development in children and adolescents having a co-twin with Down syndrome. STUDY DESIGN: A case control study with an individually matched control group was conducted. Participants included families with twins discordant for Down syndrome as well as with typically developing twins. The group of unaffected co-twins aged 4-16 years was compared with a control group of typically developing twins in terms of general cognitive abilities, behavioral problems, and prosocial behavior. The age and sex and the sex composition of the twins were individually matched. The Sijnders-Oomen nonverbal intelligence test was applied to assess children's IQ, and parents completed the Strength and Difficulties Questionnaire. RESULTS: The unaffected co-twins did not differ from typically developing twins with respect to their IQ. Concerning the psychosocial development, significantly heightened values in unaffected co-twins twins were only obtained for the conduct problems scale (P = .01; r = 0.45), neither for the total difficulties score nor for the other behavioral problem scales significant differences were found. CONCLUSIONS: The general cognitive development of the unaffected co-twin of children with Down syndrome is not affected by the presence of their Down syndrome twin. Unaffected co-twins showed increased conduct problems, which is most pronounced in the younger children.

Familial coaggregation of major psychiatric disorders among first-degree relatives of patients with obsessive-compulsive disorder: a nationwide study.

BACKGROUND: Whether the first-degree relatives (FDRs) of patients with obsessive-compulsive disorder (OCD) have an increased risk of the major psychiatric disorders, namely schizophrenia, bipolar disorder, OCD, major depressive disorder (MDD), autism spectrum disorder (ASD), and attention deficit hyperactivity disorder (ADHD), remains unclear. METHODS: Using the Taiwan National Health Insurance Research Database with the whole population sample size (n = 23 258 175), 89 500 FDRs, including parents, offspring, siblings, and twins, of patients with OCD were identified in our study. The relative risks (RRs) of major psychiatric disorders were assessed among FDRs of patients with OCD. RESULTS: FDRs of patients with OCD had higher RRs of major psychiatric disorders, namely OCD (RR 8.11, 95% confidence interval (CI) 7.68-8.57), bipolar disorder (RR 2.85, 95% CI 2.68-3.04), MDD (RR 2.67, 95% CI 2.58-2.76), ASD (RR 2.38, 95% CI 2.10-2.71), ADHD (RR 2.19, 95% CI 2.07-2.32), and schizophrenia (RR 1.97, 95% CI 1.86-2.09), compared with the total population. Different familial kinships of FDRs, such as parents, offspring, siblings, and twins consistently had increased risks for these disorders. In addition, a dose-dependent relationship was found between the numbers of OCD probands and the risk of each major psychiatric disorder. CONCLUSIONS: The FDRs, including parents, offspring, siblings, and twins, of patients with OCD have a higher risk of OCD, schizophrenia, bipolar disorder, MDD, ADHD, and ASD. The familial co-aggregation of OCD with OCD and other major psychiatric disorders was existent in a dose-dependent manner. Given the increased risks of psychiatric disorders, medical practitioners should closely monitor the mental health of the FDRs of patients with OCD.

The causal nature of the association between resting pulse in late adolescence and risk for internalizing and externalizing disorders: a co-relative analysis in a national male Swedish sample.

BACKGROUND: Resting pulse is robustly and inversely associated with the risk for externalizing disorders and may be positively associated with internalizing disorders. We know little about the causal nature of these associations. METHODS: We examined resting pulse at conscription examination in 369 301 males born 1960-80 with a mean (s.d.) follow-up of 29.1 (7.7) years. From pulse rates, we predicted, using Cox models, the risk for criminal behavior (CB), drug abuse (DA), alcohol use disorder (AUD), major depression (MD), and anxiety disorders (AD), assessed from medical, criminal, and pharmacy registries. Co-relative analyses were conducted on the general population, cousin, half-sibling, full-sibling, and monozygotic pairs discordant for the outcome. Twin/sibling modeling for pulse was performed using OpenMX. RESULTS: Familial resemblance for pulse resulted entirely from genetic factors. In the general population, the risk for externalizing disorders (CB, DA, and AUD) and internalizing disorders (MD and AD) were, respectively, significantly associated with low and high resting pulse rate. For CB, DA, and AUD, co-relative analyses showed that the inverse association with pulse resulted entirely from familial common causes (aka 'confounders'). By contrast, co-relative analyses found that the association between higher pulse and MD and AD resulted from direct causal effects. CONCLUSIONS: Resting pulse has a negative and positive association with, respectively, the risk for externalizing and for internalizing disorders. Co-relative analyses indicate that the nature of these associations differ, suggesting that elevated pulse appears to directly increase the risk for internalizing disorders while the reduced pulse is a risk index for underlying traits that predispose to externalizing disorders.

Gene-Environment Interactions in Attention-Deficit/Hyperactivity Disorder Symptom Dimensions: The Role of Unhealthy Food Habits.

Background: Dietary habits were investigated as environmental risk factors for Attention-Deficit/Hyperactivity Disorder (ADHD). However, no previous studies explored the effects of dietary factors on modifying the role of genetic factors on ADHD. Methods: Based on a Swedish population-based twin study with 1518 twin pairs aged 20-47 years, we tested whether the importance of genetic and environmental effects on ADHD varied as a function of dietary habits. Self-reported dietary habits and ADHD symptoms were collected. Twin methods were used to test the degree to which high-sugar and unhealthy food intake moderated the genetic and environmental influences on ADHD symptoms. Results: In middle-aged adults, genetic influences on inattention symptoms were statistically significantly higher among individuals with higher levels of high-sugar (45%, 95%CI: 25-54%) and unhealthy food intake (51%, 95%CI: 31-60%), compared with those with lower levels of consumption of high-sugar (36%, 95%CI: 25-47%) and unhealthy foods (30%, 95%CI: 20-41%). Similar patterns were also found for the associations between hyperactivity/impulsivity and high-sugar/unhealthy food intake, even though the moderation effects were not statistically significant. Conclusion The present study suggests that genetic factors play a more prominent role in individual differences of ADHD symptoms in the presence of the high consumption of sugar and unhealthy foods. Future longitudinal studies with multiple assessments of ADHD and dietary habits are needed to replicate our findings.

Exploring the Associations Between Delayed School Entry and Achievement in Primary and Secondary School.

This research investigated whether delayed school entry was associated with higher achievement in national tests of reading and numeracy in Grades 3, 5, 7, and 9 (n = 2,823). Delayed entry was related to advantages in reading (0.14 SD) and numeracy (0.08 SD) at Grade 3, although little variance was explained (1%-2%). This slight advantage persisted for both domains in Grades 5 and 7, albeit with smaller effects. In Grade 9 there was no association between delayed entry and either reading or numeracy. Exploratory analyses with subsamples in each grade (n = 424-667) revealed no associations between delayed entry and achievement after controlling for inattention and hyperactivity, and negative associations between inattention and achievement in all grades in both domains (-0.33, -0.49 SD).

Transitions in alcohol use over time: a survival analysis.

BACKGROUND: The current study examined the predictors of the onset of alcohol use as well as predictors of remission and relapse, both from heavy drinking and from alcohol dependence. Similarities and differences in both clinical and psychosocial predictors across the transitions were examined. METHODS: A sample of men from the Vietnam Era Twin Registry (N = 1769) completed an assessment of lifetime drinking history, which allowed age markers for starting and stopping different drinking patterns. The men also completed various assessments regarding personality, alcohol motives, and psychiatric diagnoses. Survival analyses were used to examine the predictors of the three transitions of onset, remission, and relapse for the phenotypes of heavy drinking and of alcohol dependence, censoring the individuals who had not yet experienced an event. RESULTS: As expected, predictors of onset for drinking, heavy drinking, and alcohol dependence were largely consistent and included externalizing symptomology, nicotine dependence, and cotwin history of drinking as risk factors. Predictors of remission from heavy drinking, somewhat similarly to remission from alcohol dependence, included the risk factor of externalizing disorders but also, as predicted, included more risk and protective factors in the psychosocial realm that were not predictors of onset. Contrary to our prediction, relapse to heavy drinking and alcohol dependence were predicted largely by unique psychosocial risk and protective factors including social and coping motives. CONCLUSION: Current findings extend the findings of past research to remission and relapse in the later decades of life and have implications for treatment of alcohol use problems.

Corroborative evidence for an association between initial hypothalamic-pituitary-adrenocortical axis reactivity and subsequent habituation in humans.

BACKGROUND: The extant literature predicts that initial hypothalamic-pituitary-adrenocortical (HPA) axis response magnitude and subsequent habituation are associated with health, such that both heightened stress reactivity and non-habituation to repeated stressors are associated with disease. Yet, despite evidence for an association between initial HPA axis reactivity and subsequent habituation, the extant literature often considers health implications of these stress response patterns independently or make interpretations based on an initial response alone. This may be because past tests of the association between reactivity and habituation were subject to statistical bias (e.g., regression to the mean), and no prior work has examined the association between initial cortisol reactivity and subsequent habituation using analytic strategies capable of estimating the unbiased relationship between initial value (i.e., reactivity) and subsequent change (i.e., habituation). Accordingly, the present investigation drew from two previously published studies to test the association between initial HPA axis reactivity and subsequent habituation using analytic strategies capable of estimating the relationship between initial reactivity and subsequent habituation with minimal bias. METHODS: We examined salivary cortisol and plasma ACTH responses to three repeated social-evaluative stressors (Study 1) and salivary cortisol responses to two repeated social-evaluative stressors (Study 2). RESULTS: As predicted, results indicated a negative relationship (Pearson's r ranging from -0.27 to -0.91) where initial HPA axis reactivity was associated with subsequent habituation across both studies, even when using estimation procedures capable of producing an unbiased estimate of this relationship. CONCLUSIONS: Results support the claim that initial HPA axis reactivity to acute stress is associated with subsequent habituation, such that initially high reactors are likely to habituate, whereas initially blunted reactors are likely to sensitize. In view of these results, hypothesized long-term health implications of acute cortisol reactivity and habituation patterns should be considered in tandem.

Attention-deficit/hyperactivity disorder symptoms and dietary habits in adulthood: A large population-based twin study in Sweden.

Associations between adult attention-deficit/hyperactivity disorder (ADHD) symptoms and dietary habits have not been well established and the underlying mechanisms remain unclear. We explored these associations using a Swedish population-based twin study with 17,999 individuals aged 20-47 years. We estimated correlations between inattention and hyperactivity/impulsivity with dietary habits and fitted twin models to determine the genetic and environmental contributions. Dietary habits were defined as (a) consumption of food groups, (b) consumption of food items rich in particular macronutrients, and (c) healthy and unhealthy dietary patterns. At the phenotypic level, inattention was positively correlated with seafood, high-fat, high-sugar, high-protein food consumptions, and unhealthy dietary pattern, with correlation coefficients ranging from 0.03 (95%CI: 0.01, 0.05) to 0.13 (95% CI: 0.11, 0.15). Inattention was negatively correlated with fruits, vegetables consumptions and healthy dietary pattern, with correlation coefficients ranging from -0.06 (95%CI: -0.08, -0.04) to -0.07 (95%CI: -0.09, -0.05). Hyperactivity/impulsivity and dietary habits showed similar but weaker patterns compared to inattention. All associations remained stable across age, sex and socioeconomic status. Nonshared environmental effects contributed substantially to the correlations of inattention (56-60%) and hyperactivity/impulsivity (63-80%) with dietary habits. The highest and lowest genetic correlations were between inattention and high-sugar food (rA = .16, 95% CI: 0.07, 0.25), and between hyperactivity/impulsivity and unhealthy dietary pattern (rA = .05, 95% CI: -0.05, 0.14), respectively. We found phenotypic and etiological overlap between ADHD and dietary habits, although these associations were weak. Our findings contribute to a better understanding of common etiological pathways between ADHD symptoms and various dietary habits.