Personality and risk of hospital diagnosed mental disorder: a 35 years' prospective study.

PURPOSE: The present study examined the prospective association of neuroticism, extraversion and psychoticism with risk of hospital diagnosed mental disorder, examining intelligence as a potential confounder of this association. METHODS: A total of 1118 Danish men and women completed the Eysenck personality questionnaire at the mean age of 27 years. Information on psychiatric diagnoses was obtained by linking the study population to the national Danish psychiatric registers, and risk of diagnoses associated with each personality trait was examined using multiple Cox regression in models including the three personality traits unadjusted and adjusted for intelligence. Participants with diagnosis from a psychiatric department prior to the personality assessment were excluded. RESULTS: In total, 122 participants were diagnosed with a mental disorder during follow-up. Neuroticism significantly predicted risk of anxiety-, adjustment-, personality- and alcohol and substance abuse diagnoses. Extraversion did not significantly predict any diagnosis type, while psychoticism predicted a combined category of mood and anxiety diagnoses. Despite intelligence being a significant predictor of the majority of the included diagnoses, adjusting for intelligence did not substantially influence any trait-disorder associations. CONCLUSION: The results confirm high neuroticism as a prospective vulnerability factor for mental disorder and indicate high psychoticism to be a potential risk factor for mood and anxiety disorders. These associations are not confounded by intelligence.

Traumatic brain injury and risk of dementia at different levels of cognitive ability and education.

BACKGROUND AND PURPOSE: The effect of cognitive resources on the risk of dementia following traumatic brain injury (TBI) has hardly been investigated. The aim of this study was to examine the influence of cognitive ability and education in young adulthood on the association between TBI and dementia in men. METHOD: A cohort of 658 447 Danish men, born between 1939 and 1959, who had been cognitively assessed at conscription were followed in the Danish National Patient Registry and the National Prescription Registry from 1977 through 2016 for incident TBI and dementia. The association between TBI and dementia was analysed using Cox proportional regression. RESULTS: During follow-up, 29 781(4.5%) men experienced TBI and 10 971(1.7%) developed dementia. TBI was associated with a higher risk of subsequent dementia after adjustment for cognitive ability, education and psychiatric comorbidity. The risk estimate was higher for early-onset dementia (hazard ratio 5.49, 95% confidence interval 4.97-6.06) than for dementia diagnosed after age 60 years (hazard ratio 2.85, 95% confidence interval 2.63-3.10). The association was slightly stronger in men with the highest cognitive scores or education than amongst those at lower levels. CONCLUSION: Young adult cognitive ability did not explain a relatively strong association between TBI and dementia, and no evidence was found that cognitive ability or education was protective.

Grip Work Measurement with the Jamar Dynamometer: Validation of a Simple Equation for Clinical Use.

OBJECTIVES: Previously, we developed and validated an easy test to measure muscle fatigability during sustained maximal handgrip contraction in older persons using a Martin Vigorimeter device. This study aimed at validating the equation to estimate grip work (GW) during sustained maximal handgrip contraction, by monitoring continuously the grip strength (GS) decay using a Jamar Dynamometer-like (JD) device. DESIGN: Cross sectional, explorative study. SETTING: Data collection took place at The National Research Centre for the Working Environment in Copenhagen, Denmark. PARTICIPANTS: 962 subjects, belonging to a subgroup of the Copenhagen Aging and Midlife Biobank, were enrolled. METHODS: GS was recorded continuously during sustained maximal contraction until it dropped to 50% of its maximum and fatigue resistance (FR, time to fatigue) was noted. GW, area under the force-time curve, was compared to its estimate which was calculated as GWestimated=GSmax*0.75*FR. RESULTS: Excellent correlation was found between GWestimated and GWmeasured (R²=0.98 p<0.001). The equation slightly overestimated GW by 6.04 kg*s (95% CI[-0.08, 12.15]) with a coefficient of variation method error of 6%. CONCLUSION: GW estimation is a valid parameter reflecting muscle work output during a sustained maximal grip effort in healthy middle-aged community-dwelling persons when using a JD. GW estimation is a promising outcome parameter in comprehensive geriatric assessment and its validation for commonly used instruments in geriatric practice will increase its clinical implementation.

Alcohol and delirium tremens: effects of average number of drinks per day and beverage type.

OBJECTIVE: Associations of amount of alcohol intake and beverage type with the risk of delirium tremens (DT) have not been studied. This longitudinal study investigated if the average number of drinks per day and beverage type predict DT. METHODS: A cohort of 3 582 alcohol-dependent men and women aged 19-82 without previous DT were interviewed about alcohol intake and beverage type at baseline in 1994-2005 and followed through record linkage in Danish nationwide registers to identify incident DT. Data were analyzed by means of Cox regression models. RESULTS: An average number of drinks per day of 20-30 or >30 was associated with hazard ratios (HRs) of 1.38 (95% CI 1.03-1.84) and 1.64 (95% CI 1.19-2.27) relative to the reference category (1-9 drinks). Independently of amount consumed and covariates (age, gender, civil status and work status), beverage type (spirits vs. mixed alcohol) was associated with a HR of 1.63 (95% CI 1.08-2.46). Male gender was robustly associated with increased risk (HR = 1.62 (95% CI 1.25-2.08). CONCLUSIONS: In alcohol-dependent men and women, daily alcohol intake above a threshold of 20 beverages or 240 g alcohol and a preference for spirits increase the risk of developing DT.

Association studies of genetic scores of serum vitamin B12 and folate levels with symptoms of depression and anxiety in two danish population studies.

BACKGROUND/OBJECTIVES: Observational studies have suggested low serum levels of vitamin B12 or folate to be risk factors of depression and anxiety. However, these results may be biased by confounding and reverse causation. Mendelian randomization studies are not subject to these limitations. The aim was to examine the association of genetic scores of vitamin B12 and folate-associated alleles with depression and anxiety. SUBJECTS/METHODS: The study included 4126 participants from two Danish population-based studies. Serum vitamin B12 and folate were measured. Weighed allele scores were calculated as the sum of weights (genetic effect sizes) for 12 and two variants increasing circulating levels of vitamin B12 and folate, respectively. Symptoms of depression and anxiety were assessed by the Symptom Check List (SCL)-90-R, and self-reported doctor-diagnosed depression and anxiety. RESULTS: An increased weighed allele score for serum vitamin B12 was associated with decreased odds of a SCL-90-R score above the 90th percentile (OR 0.540 (95%CI 0.302-0.967)) in Health2006 but not in Inter99, in the pooled analysis (OR 0.817 (95%CI 0.331-2.018)) or with other outcomes. The weighed allele score for serum folate was not associated with any of the measured outcome variables: SCL-90-R scores of depression (pooled OR 0.603 (95%CI 0.101-3.602)), anxiety (pooled OR 0.619 (95%CI 0.110-3.495)), combined score or history of doctor-diagnosed depression or anxiety. CONCLUSION: Our results do not provide evidence for a causal effect of circulating folate or vitamin B12 on the risk of depression or anxiety. However, we cannot rule out small to moderate effects, and thus large scale studies are needed.

Structure and clinical correlates of obsessive-compulsive symptoms in a large sample of children and adolescents: a factor analytic study across five nations.

The underlying structure of obsessive-compulsive disorder (OCD) remains to be confirmed in child and adolescent populations. In this paper we report the first factor analytic study of individual OCD items from Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS). OCD symptoms were assessed using the CY-BOCS symptom checklist in a sample of 854 patients with OCD (7-18 years of age) recruited from clinics in five countries. Pooled data were subjected to exploratory and confirmatory factor analysis (CFA) to identify the optimal factor structure. Various models were tested for age and gender subgroups. Also, the invariance of the solution across age and gender was tested and associations with demographic and clinical factors were explored. A three-factor model provided the best-fit solution. It consisted of the following factors: (1) harm/sexual, (2) symmetry/hoarding, (3) contamination/cleaning. The factor structure was invariant for age and gender across subgroups. Factor one was significantly correlated with anxiety, and factor two with depression and anxiety. Factor three was negatively correlated with tic disorder and attention-deficit/hyperactivity disorder (ADHD). Females had higher scores on factor two than males. The OCD symptom structure in children and adolescents is consistent across age and gender and similar to results from recent child and adolescents although hoarding may not be a separate factor. Our three-factor structure is almost identical to that seen in early studies on adults. Common mental disorders had specific patterns of associations with the different factors.

Exploring social cognition in schizophrenia.

The aim of the study was to compare social cognition between groups of patients diagnosed with schizophrenia and healthy controls and to replicate two previous studies using tests of social cognition that may be particularly sensitive to social cognitive deficits in schizophrenia. Thirty-eight first-admitted patients with schizophrenia and 38 healthy controls solved 11 "imaginary conversation (i.e., theory of mind)" items, 10 "psychological understanding" items, and 10 "practical understanding" items. Statistical tests were made of unadjusted and adjusted group differences in models adjusting for intelligence and neuropsychological test performance. Healthy controls performed better than patients on all types of social cognitive tests, particularly on "psychological understanding." However, after adjusting for intelligence and neuropsychological test performance, all group differences became nonsignificant. When intelligence and global cognitive functioning is taken into account, schizophrenia patients and healthy controls perform similarly on social cognitive tests.

Tracking of body mass index from 7 to 69 years of age.

BACKGROUND: Heavy children have an increased risk of being overweight young adults. Whether this risk remains in late adulthood is not well-understood. We investigated body mass index (BMI; kg m(-2)) tracking from childhood to late adulthood. METHODS: From the Copenhagen School Health Records Register, 72 959 men and 25 252 women born between 1930 and 1989 with BMI values at 7 and/or 13 years and as adults were included. Using a meta-regression approach, age- and sex-specific partial correlation analyses and logistic regressions were performed. RESULTS: Correlations between BMI at 7 years and young adult ages (18-19 years) were r=0.55 for men and r=0.55 for women. At late ages (60-69 years) these were r=0.28 for men and r=0.26 for women. The correlations did not differ by birth years. Compared with normal-weight 7-year-olds, overweight children had a higher odds of overweight at 18-19 years; odds ratio (OR)=14.02 (95% confidence interval (CI): 12.14-16.19) for men and 10.46 (95% CI: 4.82-22.70) for women. At ages 60-69 years ORs were 5.46 (95% CI: 0.95-31.36) for men and 1.61 (95% CI: 0.83-3.15) for women. Correlations and ORs were stronger at age 13 years than age 7 years as expected, but the overall patterns were similar. CONCLUSIONS: BMI tracking was weaker at late adult ages than at young adult ages. Although BMI tracks across the life course, childhood BMI is relatively poor at identifying later adult overweight or obesity at ages when chronic diseases generally emerge.

Childhood body mass index and risk of schizophrenia in relation to childhood age, sex and age of first contact with schizophrenia.

UNLABELLED: Childhood leanness is associated with an increased risk of schizophrenia, but the effects of gender, age at anthropometric measurements and age at first diagnosis on this relationship are unclear. The present study aimed at elucidating these associations. METHODS: Population-based cohort study with childhood anthropometric measures obtained annually from the age of 7 to 13 years in 253,353 Danes born 1930-1976 and followed to 31 December 2010. During this period, 4936 were registered with schizophrenia. The associations of childhood BMI with risk of schizophrenia were estimated with Cox regression models. RESULTS: Childhood BMI was significantly inversely associated with risk of schizophrenia, however with different patterns among boys and girls. In boys, childhood BMI had an inverse non-linear association with schizophrenia risk dependent on age at diagnosis; in particular, a surprisingly strong association was found between leanness and later onset of schizophrenia. In girls, the risk of schizophrenia decreased linearly with increasing BMI z-score (HR: 0.93; 95% CI: 0.88-0.98). In both boys and girls, birth weight was inversely associated with later risk. In girls, but not in boys, birth weight appeared to significantly modify the associations; there was a somewhat stronger inverse association in the lowest birth weight category. CONCLUSION: Birth weight as well as childhood BMI at ages 7 through 13 years is associated with risk of schizophrenia in both genders, but with a particular high risk of late-onset in lean boys irrespective of birth weight, and in lean girls with low birth weight. If replicated, these observations may inform preventive efforts build on schizophrenia trajectories rooted in early life.

Serum 25-hydroxyvitamin D and self-reported mental health status in adult Danes.

BACKGROUND/OBJECTIVES: Vitamin D receptors and vitamin D-metabolising enzymes are present in the brain and in the central nervous system at sites responsible for the regulation of emotions and behaviour. This raises the hypothesis that low vitamin D is related to poor mental health. Our aim was to examine the association between serum 25-hydroxyvitamin D (25(OH)D) and the self-reported symptoms and diagnosis of depression and anxiety in the adult general population. SUBJECTS/METHODS: Serum 25(OH)D was measured in three Danish population-based studies, including 5308 adults aged 18-64 years. After 5 years, 2004 participants were re-examined. Symptoms of depression and anxiety were assessed by the Symptom Check List (SCL)-90-R, and self-reported doctor-diagnosed depression and anxiety was recorded by using a questionnaire. RESULTS: Serum 25(OH)D was not associated with SCL average scores for depression and anxiety when analysed by quantile median regression adjusted for sex, age and other potential confounders. The ß-coefficient and 95% confidence interval (CI) per 10 nmol/l serum 25(OH)D were 0.00 (-0.00 to 0.01) and P=0.23 for depression and -0.00 (-0.01 to 0.00) and P=0.19 for anxiety. Furthermore, no evidence of an association was observed with longitudinal changes (combining depression and anxiety score: ß (95% CI)=0.00 (-0.00 to 0.00), P=0.90), with scores >90 percentiles (odds ratio (OR) (95% CI)=1.02 (0.98-1.07), P=0.32), or with self-reported history (OR (95% CI)=1.02 (0.97-1.07), P=0.47) or incidence (OR (95% CI)=1.02 (0.92-1.12), P=0.77) of doctor-diagnosed depression and/or anxiety. CONCLUSIONS: Our results suggest that low serum 25(OH)D is not associated with self-reported symptoms/diagnosis of depression and anxiety.

Increased post-operative cardiopulmonary fitness in gastric bypass patients is explained by weight loss.

Roux-en-Y gastric bypass (RYGB) leads to a major weight loss in obese patients. However, given that most patients remain obese after the weight loss, regular exercise should be part of a healthier lifestyle. The primary aim of this study was to investigate the cardiopulmonary fitness in obese patients before and after RYGB. Thirty-four patients had body composition and cardiopulmonary fitness (VO2max ) assessed and completed questionnaires regarding physical activity and function twice before RYGB (time points A and B) and 4 and 18 months after surgery (time points C and D). Weight loss was 37 ± 2 kg during the study period. VO2max increased (A: 21 ± 1 vs D: 29 mL/min/kg, P < 0.001), but absolute VO2max decreased (A: 2713 ± 126 vs 2609 ± 187 mL/min, P = 0.02) and VO2max per kilogram fat free mass did not change. Self-perceived limitations to perform exercise decreased and self-perceived physical fitness increased after RYGB. Self-reported low- and high-intensity physical activity did not change. With weight loss, self-rated fitness level increased and the limitations to perform exercise decreased in RYGB patients. Nevertheless, as shown by the lower absolute VO2max , RYGB patients do not adopt new exercise habits following surgery.

The association of pre-pregnancy alcohol drinking with child neuropsychological functioning.

OBJECTIVE: To examine the effects of pre-pregnancy alcohol drinking on child neuropsychological functioning. DESIGN: Prospective follow-up study. SETTING AND POPULATION: 154 women and their children sampled from the Danish National Birth Cohort. METHODS: Participants were sampled based on maternal alcohol consumption before pregnancy. At 5 years of age, the children were tested with the Wechsler Preschool and Primary Scale of Intelligence-Revised, the Test of Everyday Attention for Children at Five (TEACh-5), and the Movement Assessment Battery for Children (MABC). The Behaviour Rating Inventory of Executive Function (BRIEF) was completed by the mothers and a preschool teacher. Parental education, maternal IQ, prenatal maternal smoking, child's age at testing, child's sex, and maternal alcohol intake during pregnancy were considered potential confounders. MAIN OUTCOME MEASURES: Performance on the Wechsler Preschool and Primary Scale of Intelligence-Revised, the TEACh-5, the MABC, and the BRIEF. RESULTS: Intake of 15-21 drinks/week on average prior to pregnancy was not associated with any of the outcomes, but intake of ≥22 drinks/week on average was associated with a significantly lower adjusted mean full scale IQ and lower adjusted means in overall attention and sustained attention score, but not in selective attention score or any of the BRIEF index scores or MABC scores. CONCLUSIONS: Intake of ≥22 drinks/week before pregnancy was associated with lower mean full scale IQ, overall attention and sustained attention. Assessment of pre-pregnancy drinking provides additional information regarding potential prenatal alcohol exposure and its implications for child neurodevelopment.

Fertility treatment and child intelligence, attention, and executive functions in 5-year-old singletons: a cohort study.

OBJECTIVE: To assess the association of fertility treatment and subfertility with offspring intelligence, attention, and executive functions in 5-year-old singletons. DESIGN: Follow-up study. SETTING: Denmark 2003-2008. POPULATION: A cohort of 1782 children sampled from the Danish National Birth Cohort. METHODS: The children were tested with a neuropsychological battery at age five. In addition to tests of intelligence, attention and executive functions, the follow up included extensive information on important covariates. The analyses were conducted using multiple linear regression and adjusted for parental educational level, maternal intelligence, age, parity, body mass index, smoking in pregnancy, alcohol consumption in pregnancy and child gender, child age, and examiner. MAIN OUTCOME MEASURES: Wechsler Preschool and Primary Scale of Intelligence-Revised, the Test of Everyday Attention for Children at Five, and the Behavior Rating Inventory of Executive Functions scores. RESULTS: A consistent pattern of nonsignificantly lower scores were only observed for intelligence and executive functions in children born after fertility treatment or by subfertile parents when the results were unadjusted for maternal intelligence and parental educational level. When adjusted for these and other covariates, there were no significant mean differences in intelligence (mean difference -2.8, 95% CI -7.8, 2.2), overall attention (-0.1, 95% CI -0.6, 0.3), or parent-rated executive functions (-0.1, 95% CI -3.0, 2.9) between children born after spontaneous conception and children born to parents conceiving after fertility treatment. Similarly, there were no significant mean differences in intelligence (mean difference 0.6, 95% CI -2.2, 3.4), overall attention (0.1, 95% CI -0.2, 0.4), or parent-rated executive functions (1.0, 95% CI -1.8, 3.7) between children born after spontaneous conception and children born to subfertile parents waiting more than 12 months before conceiving naturally. CONCLUSIONS: This study suggests that parental subfertility and fertility treatment are unrelated to offspring intelligence, attention and executive functions.

Effects of body size and change in body size from infancy through childhood on body mass index in adulthood.

BACKGROUND: Weight and weight gain throughout infancy are related to later obesity, but whether the strength of the associations varies during the infancy period is uncertain. AIMS: Our aims were to identify the period of infancy when change in body weight has the strongest association with adult body mass index (BMI) and also the extent to which these associations during infancy are mediated through childhood BMI. METHODS: The Copenhagen Perinatal Cohort, in which participants were followed from birth through 42 years of age, provided information on weight at 12 months and BMI at 42 years for 1633 individuals. Information on weight at birth, 2 weeks, 1, 2, 3, 4 and 6 months was retrieved from health visitors' records and information on BMI at ages 7 and 13 years from school health records. The associations of infant weight and weight gain standard deviation scores (SDS) with adult BMI-SDS were analyzed using multiple linear regression and path analysis. RESULTS: Higher-weight-SDS at all ages from birth to an age 12 months were associated with higher-BMI-SDS at 42 years (regression coefficients 0.08-0.12). Infant weight gain-SDS was associated with greater BMI-SDS at 42 years only between birth and 3 months (0.09, 95% confidence intervals (CI) 0.04, 0.15) driven by an association between 2 and 3 months (0.12, 95% CI: 0.04, 0.20). The latter was partly mediated through later BMI in the path analysis. Infant weight gain-SDS between 3 and 12 months was not associated with greater BMI-SDS at 42 years. CONCLUSIONS: Faster weight gain during only the first 3 months of infancy was associated with increased adult BMI, although not in a consistent monthly pattern. Adult BMI is more sensitive to high weight gain during early infancy than late infancy, but not specifically to the first month of life.

Does Harm Avoidance mediate effects of recollected parental bonding on mental distress in adulthood?

BACKGROUND: Adverse early life conditions such as perceived low quality of parental bonding increase vulnerability to stress and psychopathology in adulthood. However, the mechanisms by which perceptions of parental bonding translate into vulnerability are unclear and remain sparsely investigated in healthy populations. We proposed a model, in which the personality trait Harm Avoidance would mediate effects of recollected parental bonding during the first sixteen years of life on measures of perceived stress and mental distress severity in adulthood. METHOD: Five-hundred-eighteen adults (65.1 % women), aged 18-53years, completed questionnaires of parental bonding, perceived stress, trait Harm Avoidance, and severity of mental distress. Direct and indirect effects mediated through trait Harm Avoidance were examined in a structural equation model. RESULTS: Under the causal assumptions of our proposed model, indirect effects of trait Harm Avoidance mediated the relationship between parental overprotection and severity of mental distress, while significantly attenuating the direct effects of parental care on severity of mental distress. Moreover, indirect effects of trait Harm Avoidance significantly attenuated the direct effects of parental overprotection and care on perceived stress. CONCLUSION: In this large sample of mentally healthy adults, recollected parental bonding was significantly associated with levels of perceived stress and severity of mental distress. The results from our proposed model further suggest that trait Harm Avoidance may be a developmental link, by which the quality of recollected parental bonding in childhood translates into adult vulnerability to stress and mental distress.

The effects of low to moderate alcohol consumption and binge drinking in early pregnancy on behaviour in 5-year-old children: a prospective cohort study on 1628 children.

OBJECTIVE: To examine the effects of low to moderate maternal alcohol consumption and binge drinking in early pregnancy on behaviour in children at the age of 5 years. DESIGN: Prospective cohort study. SETTING: Neuropsychological testing in four Danish cities, 2003-2008. POPULATION: A total of 1628 women and their children sampled from the Danish National Birth Cohort. METHODS: Participants were sampled based on maternal alcohol drinking patterns during early pregnancy. When the children were 5 years of age the parent and teacher versions of the Strengths and Difficulties Questionnaire (SDQ) were completed by the mothers and a preschool teacher, respectively. The full statistical model included the following potential confounding factors: maternal binge drinking or low to moderate alcohol consumption, respectively; parental education; maternal IQ; prenatal maternal smoking; the child's age at testing; the child's gender; maternal age; parity; maternal marital status; family home environment; postnatal parental smoking; prepregnancy maternal body mass index (BMI); and the child's health status. MAIN OUTCOME MEASURE: Behaviour among children assessed by the SDQ parent and teacher forms. RESULTS: Adjusted for all potential confounding factors, no statistically significant associations were observed between maternal low to moderate average weekly alcohol consumption and SDQ behavioural scores (OR 1.1, 95% CI 0.5-2.3; OR 1.1, 95% CI 0.6-2.1 for the total difficulties scores) or between binge drinking and SDQ behavioural scores (OR 1.2, 95% CI 0.8-1.7; OR 0.8, 95% CI 0.6-1.2). CONCLUSION: This study observed no consistent effects of low to moderate alcohol consumption or binge drinking in early pregnancy on offspring behaviour at the age of 5 years.

Early motor developmental milestones and level of neuroticism in young adulthood: a 23-year follow-up study of the Copenhagen Perinatal Cohort.

BACKGROUND: Studies investigating early developmental factors in relation to psychopathology have mainly focused on schizophrenia. The personality dimension of neuroticism seems to be a general risk factor for psychopathology, but evidence on associations between early developmental precursors and personality traits is almost non-existent. This study is therefore the first to investigate associations between early motor developmental milestones and neuroticism in adulthood. Method Mothers of 9125 children of the Copenhagen Perinatal Cohort recorded 12 developmental milestones during the child's first year of life. A subsample of the cohort comprising 1182 individuals participated in a follow-up when they were aged 20-34 years and were administered the Eysenck Personality Questionnaire (EPQ). Associations between motor developmental milestones and level of neuroticism, extraversion and psychoticism were analysed by multiple linear regression adjusting for for sex, single-mother status, parity, mother's age, father's age, parental social status and birth weight. RESULTS: Among the 1182 participants with information on the EPQ, information on milestones was available for 968 participants. Infants who developed high levels of neuroticism as adults tended to sit without support, crawl, and walk with and without support significantly later than individuals with low levels of neuroticism (p values <0.05). These results remained significant after adjustment for the included covariates and for adult intelligence. CONCLUSIONS: The findings are the first of their kind and suggest that delays in early motor development may not only characterize psychopathological disorders such as schizophrenia, but may also be associated with the personality dimension of neuroticism in adulthood.

Neonatal levels of neurotrophic factors and risk of autism spectrum disorders.

OBJECTIVE: To examine levels of 3 neurotrophic factors (NTFs): Brain derived neurotrophic factor (BDNF), Neurotrophin-4 (NT-4), and transforming growth factor-ß (TGF-ß) in dried blood spot samples of neonates diagnosed with autism spectrum disorders (ASD) later in life and frequency-matched controls. METHOD: Biologic samples were retrieved from the Danish Newborn Screening Biobank. NTFs for 414 ASD cases and 820 controls were measured using Luminex technology. Associations were analyzed with continuous measures (Tobit regression) as well as dichotomized at the lower and upper 10th percentiles cutoff points derived from the controls' distributions (logistic regression). RESULTS: ASD cases were more likely to have BDNF levels falling in the lower 10th percentile (odds ratios [OR], 1.53 [95% confidence intervals (CI), 1.04-2.24], P-value = 0.03). Similar pattern was seen for TGF-ß in females with ASD (OR, 2.36 [95% CI, 1.05-5.33], P-value = 0.04). For NT-4, however, ASD cases diagnosed with ICD-10 only were less likely to have levels in upper 10th percentile compared with controls (OR, 0.22 [95% CI, 0.05-0.98], P-value = 0.05). CONCLUSION: Results cautiously indicate decreased NTFs levels during neonatal period in ASD. This may contribute to the pathophysiology of ASD through impairments of neuroplasticity. Further research is required to confirm our results and to examine the potential therapeutic effects of NTFs in ASD.

The effect of different alcohol drinking patterns in early to mid pregnancy on the child's intelligence, attention, and executive function.

OBJECTIVE: To conduct a combined analysis of the estimated effects of maternal average weekly alcohol consumption, and any binge drinking, in early to mid pregnancy on general intelligence, attention, and executive function in 5-year-old children. DESIGN: Follow-up study. SETTING: Neuropsychological testing in four Danish cities 2003-2008. POPULATION: A cohort of 1628 women and their children sampled from the Danish National Birth Cohort. METHODS: Participants were sampled based on maternal alcohol consumption during early pregnancy. At age 5 years, the children were tested for general intelligence, attention, and executive function. The three outcomes were analysed together in a multivariate model to obtain joint estimates and P values for the association of alcohol across outcomes. The effects of low to moderate alcohol consumption and binge drinking in early pregnancy were adjusted for a wide range of potential confounding factors. MAIN OUTCOME MEASURES: Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R), the Test of Everyday Attention for Children at Five (TEACh-5), and the Behavior Rating Inventory of Executive Functions (BRIEF) scores. RESULTS: Multivariate analyses showed no statistically significant effects arising from average weekly alcohol consumption or any binge drinking, either individually or in combination. These results replicate findings from separate analyses of each outcome variable. CONCLUSIONS: The present study contributes comprehensive methodological and statistical approaches that should be incorporated in future studies of low to moderate alcohol consumption and binge drinking during pregnancy. Furthermore, as no safe level of drinking during pregnancy has been established, the most conservative advice for women is not to drink alcohol during pregnancy. However, the present study suggests that small volumes consumed occasionally may not present serious concern.

The effects of low to moderate prenatal alcohol exposure in early pregnancy on IQ in 5-year-old children.

OBJECTIVE: To examine the effects of low to moderate maternal alcohol consumption during early pregnancy on children's intelligence (IQ) at age 5 years. DESIGN: Prospective follow-up study. SETTING: Neuropsychological testing in four Danish cities 2003-2008. POPULATION: A cohort of 1628 women and their children sampled from the Danish National Birth Cohort. METHODS: Participants were sampled based on maternal alcohol consumption during pregnancy. At 5 years of age, children were tested with the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R). Parental education, maternal IQ, maternal smoking in pregnancy, the child's age at testing, gender, and tester were considered core confounding factors, whereas the full model also controlled for maternal binge drinking, age, BMI, parity, home environment, postnatal smoking in the home, health status, and indicators for hearing and vision impairments. MAIN OUTCOME MEASURES: The WPPSI-R. RESULTS: No differences in test performance were observed between children whose mothers reported consuming between one and four or between five and eight drinks per week at some point during pregnancy, compared with children of mothers who abstained. For women who reported consuming nine or more drinks per week no differences were observed for mean differences; however, the risks of low full-scale IQ (OR 4.6; 95% CI 1.2-18.2) and low verbal IQ (OR 5.9; 95% CI 1.4-24.9) scores, but not low performance IQ score, were increased. CONCLUSIONS: Maternal consumption of low to moderate quantities of alcohol during pregnancy was not associated with the mean IQ score of preschool children. Despite these findings, acceptable levels of alcohol use during pregnancy have not yet been established, and conservative advice for women continues to be to avoid alcohol use during pregnancy.