Prevalence of Autism Spectrum Disorder in 7-9-Year-Old Children in Denmark, Finland, France and Iceland: A Population-Based Registries Approach Within the ASDEU Project.

We estimated autism spectrum disorder (ASD) prevalence in 7-9 year-old children in 2015 using data from three nationwide health registry systems (Denmark, Finland, Iceland) and two French population-based regional registries. Prevalence ranged from 0.48% in South-East France to 3.13% in Iceland (South-West France: 0.73%, Finland: 0.77%, Denmark: 1.26%). Male/female ratios ranged from 3.3 in Finland to 5.4 in South-West France. Between 12% (Denmark) and 39% (South-West France) of cases were diagnosed with intellectual disability. The variations in population-based ASD prevalence across four European countries with universal health care practices likely reflect variation in detection, referral and diagnosis practices and autism awareness across these areas. Using established population-based data systems is an efficient approach to monitor ASD prevalence trends over time.

Sensory Abnormality and Quantitative Autism Traits in Children With and Without Autism Spectrum Disorder in an Epidemiological Population.

Sensory abnormalities (SAs) are recognized features in Autism Spectrum Disorder (ASD), and a relationship between SAs and ASD traits is also suggested in general population. Our aims were to estimate the prevalence of SAs in three different settings, and to study the association between SAs and quantitative autism traits (QAT) using the Autism Spectrum Screening Questionnaire (ASSQ) and a parental questionnaire. In an epidemiological population of 8-year-old children (n = 4397), the prevalence of SAs was 8.3%, in an ASD sample (n = 28), 53.6%, and in a non-ASD sample (n = 4369), 8.0%, respectively. Tactile and auditory hypersensitivity predicted an ASD diagnosis. The ASSQ was able to differentiate children with and without SA. In conclusion, QAT level and SAs were associated in all study samples.

Longitudinal associations between childhood and adulthood externalizing and internalizing psychopathology and adolescent substance use.

BACKGROUND: Emotional and behavioral problems are commonly associated with substance use in adolescence but it is unclear whether substance use precedes or follows mental health problems. The aim was to investigate longitudinal associations between externalizing and internalizing psychopathology and substance use in a prospective population study design. METHOD: The sample was the Northern Finland Birth Cohort 1986 Study (NFBC 1986; n = 6349; 3103 males). Externalizing and internalizing mental health problems were assessed at age 8 years (Rutter scales), substance use and externalizing and internalizing problems [Youth Self-Report (YSR)] at age 15-16 years, and hospital diagnoses for internalizing disorders (age 25) and criminal offences (age 20) from nationwide registers in adulthood. RESULTS: Externalizing problems at age 8 were associated with later substance use. After adjustment for sociodemographic factors, parental alcohol use and psychiatric disorders, and earlier externalizing and internalizing problems, substance use predicted criminality, especially among males, with the highest odds ratio (OR) for cannabis use [adjusted OR 6.2, 95% confidence interval (CI) 3.1-12.7]. Early internalizing problems were not a risk for later substance use. Female adolescent cannabis (OR 3.2, 95% CI 1.4-7.3) and alcohol (OR 2.1, 95% CI 1.1-4.2) use predicted internalizing disorders in adulthood. CONCLUSIONS: Externalizing problems precede adolescent substance use in both genders, whereas, among boys, substance use also precedes criminal offences. Internalizing problems may follow substance use in females. These associations were robust even when taking into account previous mental health problems.

Response initiation in young adults at risk for psychosis in the Northern Finland 1986 Birth Cohort.

INTRODUCTION: This is one of the very few studies to investigate the specific executive function/processing speed component of response initiation in subjects at familial risk (FR) for psychosis, and the first such study in subjects at clinical risk (CR) for psychosis. METHODS: Participants (N = 177) were members of the general population-based Northern Finland 1986 Birth Cohort in the following four groups: FR for psychosis (n = 62), CR for psychosis (n = 21), psychosis (n = 25) and control subjects (n = 69). The response initiation of these groups was compared in three different tests: Semantic fluency, Stockings of Cambridge and Spatial working memory. RESULTS: The two risk groups did not differ significantly from control group, but differed from, and outperformed the psychosis group in semantic fluency response initiation. CONCLUSIONS: Response initiation deficits were not evident in a non-help seeking psychosis high-risk sample.

Disruptive behaviour disorder with and without attention deficit hyperactivity disorder is a risk of psychiatric hospitalization.

AIM: To evaluate the psychiatric hospitalization among adolescents diagnosed with disruptive behaviour disorders (DBD) and/or attention deficit hyperactivity disorder (ADHD). METHODS: The sample (N = 457) was drawn from the Northern Finland Birth Cohort 1986. Four groups were formed, based on the K-SADS-PL diagnostic interview procedure: adolescents with DBD (n = 44), ADHD (n = 91), comorbid DBD and ADHD (n = 72) and without either DBD or ADHD (n = 250). Information from the Finnish Hospital Discharge Register (FHDR) was used to evaluate the psychiatric hospitalization among the study subjects. RESULTS: When compared with no diagnosis group, the adolescents with behavioural disorders had an increased risk (adjusted odds ratios: DBD = 4.4, ADHD = 2.2, comorbid DBD & ADHD = 5.6) of having also psychiatric disorder in the FHDR. The onset age of the psychiatric disorders in the FHDR (medians: DBD = 14.9, ADHD = 7.5 and DBD & ADHD = 15.3 years) and the combined length of hospitalization (medians: 25, 50 and 26 days, respectively) differed among adolescents with behavioural disorders compared with those with no diagnosis (median age 12.1 years and length of hospitalization 4 days). CONCLUSION: Adolescents diagnosed with DBD (with and without ADHD) are at high risk of undergoing psychiatric hospitalization during their life.

Childhood bullying behaviors at age eight and substance use at age 18 among males. A nationwide prospective study.

Childhood bullying behaviors (bullying and victimization) were studied as risk factors for substance use among Finnish males. The study design was a nationwide prospective general population study, where information was collected in 1989 and 1999. Bullying behaviors and childhood psychopathology at age eight were collected from teachers, parents and boys themselves. At age 18, self-reports of frequent drunkenness (once a week or more often), daily heavy smoking (10 cigarettes or more per day), and illicit drug use during the past six months were obtained from 78% of the boys attending the study at age eight (n=2946). Being frequently victimized at age eight predicted daily heavy smoking, and this was evident even after adjusting for childhood family background, psychopathology at age eight and at age 18, and other forms of substance use. In multivariate analysis, bullying others frequently predicted illicit drug use, while being a victim of bullying associated with a lower occurrence of illicit drug use. Bullying behaviors had no association with frequent drunkenness independent of other factors. Accordingly, being a victim of bullying predisposes in particular to subsequent smoking. Bullying others in childhood can be regarded as an early indicator to illicit drug use later in life. The screening and intervention possibilities in order to recognize the risk group for later health compromising behaviors are emphasized.

Physical activity and fitness in adolescents at risk for psychosis within the Northern Finland 1986 Birth Cohort.

BACKGROUND: Literature regarding physical activity and fitness among subjects at risk for psychosis especially in adolescents is scarce. This study evaluated the level of physical activity and cardio-respiratory fitness among subjects at risk for psychosis in a relatively large birth cohort sample. METHODS: The study population consisted of the Northern Finland Birth Cohort 1986 including 6987 adolescents who self-reported their physical activity by responding to a postal inquiry in 2001-2002 at the age of 15-16 years. Their cardiorespiratory fitness was measured in a clinical examination by a submaximal cycle ergometer test. Vulnerability to psychosis was defined in three ways: having a parent with a history of psychosis, having prodromal symptoms of psychosis measured by PROD-screen questionnaire at the age of 15-16 years or having actually developed psychosis after the field study (in 2002-2005). The Finnish Hospital Discharge Register was used to find out about parental and the individual's own psychosis. RESULTS: Those individuals who developed psychosis were more likely to be physically inactive (OR 3.3; CI 95% (1.4-7.9) adjusted for gender, parental socio-economic status, family structure and parents' physical activity) and to have poor cardiorespiratory fitness (OR 2.2; 95% CI 0.6-7.8 adjusted for parental socio-economic status, family structure and parents' physical activity) compared to those who did not develop psychosis. CONCLUSIONS: Adolescents who would actually develop psychosis had a relatively low level of physical activity compared to their age mates. General recommendations for physical activity would be important for subjects at risk for developing psychosis in order to avoid detrimental effect of physical inactivity on overall health.

Is prenatal alcohol exposure related to inattention and hyperactivity symptoms in children? Disentangling the effects of social adversity.

BACKGROUND: Studies concerning whether exposure to low levels of maternal alcohol consumption during fetal development is related to child inattention and hyperactivity symptoms have shown conflicting results. We examine the contribution of covariates related to social adversity to resolve some inconsistencies in the extant research by conducting parallel analyses of three cohorts with varying alcohol consumption and attitudes towards alcohol use. METHODS: We compare three population-based pregnancy-offspring cohorts within the Nordic Network on ADHD from Denmark and Finland. Prenatal data were gathered via self-report during pregnancy and birth outcomes were abstracted from medical charts. A total of 21,678 reports concerning inattention and hyperactivity symptoms in children were available from the Strengths and Difficulties Questionnaire or the Rutter Scale completed by parents and/or teachers. RESULTS: Drinking patterns differed cross-nationally. Women who had at least some social adversity (young, low education, or being single) were more likely to drink than those better off in the Finnish cohort, but the opposite was true for the Danish cohorts. Prenatal alcohol exposure was not related to risk for a high inattention-hyperactivity symptom score in children across cohorts after adjustment for covariates. In contrast, maternal smoking and social adversity during pregnancy were independently and consistently associated with an increase in risk of child symptoms. CONCLUSIONS: Low doses of alcohol consumption during pregnancy were not related to child inattention/hyperactivity symptoms once social adversity and smoking were taken into account.

Do mental health problems in childhood predict chronic physical conditions among males in early adulthood? Evidence from a community-based prospective study.

BACKGROUND: Previous studies have documented associations between mental and physical health problems in cross-sectional studies, yet little is known about these relationships over time or the specificity of these associations. The aim of the current study was to examine the relationship between mental health problems in childhood at age 8 years and physical disorders in adulthood at ages 18-23 years. METHOD: Multiple logistic regression analyses were used to examine the relationship between childhood mental health problems, reported by child, parent and teacher, and physical disorders diagnosed by a physician in early adulthood. RESULTS: Significant linkages emerged between childhood mental health problems and obesity, atopic eczema, epilepsy and asthma in early adulthood. Specifically, conduct problems in childhood were associated with a significantly increased likelihood of obesity and atopic eczema; emotional problems were associated with an increased likelihood of epilepsy and asthma; and depression symptoms at age 8 were associated with an increased risk of asthma in early adulthood. CONCLUSIONS: Our findings provide the first evidence of an association between mental health problems during childhood and increased risk of specific physical health problems, mainly asthma and obesity, during early adulthood, in a representative sample of males over time. These data suggest that behavioral and emotional problems in childhood may signal vulnerability to chronic physical health problems during early adulthood.

No difference in insulin resistance and lipid levels between controls and adolescent subjects who later develop psychosis.

Type 2 diabetes and dyslipidemias co-occur frequently with psychoses, but it is not known how common they are in adolescents who later develop psychosis. We investigated waist circumference, blood glucose, lipid and insulin levels and insulin resistance in the Northern Finland 1986 Birth Cohort at the age of 15/16 (N=5410). The Social Insurance Institute register and the Finnish Hospital Discharge Register were used to find the participants who developed psychosis (N=21), and they were compared with other participants. There were no differences in the cardiometabolic variables, suggesting that psychotic episode is not preceded by glucose and lipid metabolism disturbances.

Insulin resistance and lipid levels in adolescents with familial risk for psychosis.

OBJECTIVE: Type 2 diabetes and dyslipidemias co-occur frequently with schizophrenia. It is not known how common they are in adolescents with a familial risk for psychosis. METHOD: The Northern Finland 1986 Birth Cohort consists of 9432 children born alive in the two Northernmost provinces in Finland. At the age of 15/16 they participated in clinical examination including measurements of glucose, lipids and IR, and a questionnaire including items about their diet and physical activity. The Finnish Hospital Discharge Register was used to find out non-organic psychoses in parents during 1972-2000. This familial risk was found out in 54 boys and 68 girls. Their results were compared with other cohort members. RESULTS: No differences were observed in the cardiometabolic risk factors between the study groups. CONCLUSION: Our results suggest that familial risk for psychosis is not directly associated with disturbances of glucose and lipid metabolism among adolescents.

Maternal adiposity prior to pregnancy is associated with ADHD symptoms in offspring: evidence from three prospective pregnancy cohorts.

OBJECTIVES: We examine whether pregnancy weight (pre-pregnancy body mass index (BMI) and/or weight gain) is related to core symptoms of attention deficit hyperactivity disorder (ADHD) in school-age offspring. DESIGN: Follow-up of prospective pregnancy cohorts from Sweden, Denmark and Finland within the Nordic Network on ADHD. METHODS: Maternal pregnancy and delivery data were collected prospectively. Teachers rated inattention and hyperactivity symptoms in offspring. High scores were defined as at least one core symptom rated as 'severe' and two as 'present' (approximately 10% of children scored in this range). Logistic regression and latent class analyses were used to examine maternal pregnancy weight in relation to children's ADHD core symptoms. RESULTS: Teacher rated 12 556 school-aged children. Gestational weight gain outside of the Institute of Medicine guidelines was not related to ADHD symptoms (below recommendations: odds ratio (OR): 0.96; 95% confidence interval (CI): 0.81, 1.14; above recommendations: OR: 0.98; 95% CI: 0.82, 1.16). To examine various patterns of pre-pregnancy BMI and weight gain, we used latent class analysis and found significant associations between classes that included pre-pregnancy overweight or obesity and a high ADHD symptom score in offspring, ORs ranged between 1.37 (95% CI: 1.07, 1.75) and 1.89 (95% CI: 1.13, 3.15) adjusted for gestational age, birth weight, weight gain, pregnancy smoking, maternal age, maternal education, child gender, family structure and cohort country of origin. Children of women who were both overweight and gained a large amount of weight during gestation had a 2-fold risk of ADHD symptoms (OR: 2.10, 95% CI: 1.19, 3.72) compared to normal-weight women. CONCLUSIONS: We show for the first time that pre-pregnancy BMI is associated with ADHD symptoms in children. Our results are of public health significance if the associations are causal and will then add ADHD symptoms in offspring to the list of deleterious outcomes related to overweight and obesity in the prenatal period.

Maternal responsiveness and infant intentional communication: implications for the early communicative and linguistic development.

BACKGROUND: Maternal responsiveness has been found to have an important role in early language acquisition. From early on, children can also be regarded as active participants in interaction who demonstrate increasing competence in conveying messages to their interactive partners. Hence, in order to demonstrate consistent effects of maternal responses, it is important to take into account individual differences among children. In the present study, the relation between the frequencies of maternal responses and infant intentional communicative acts as well as their predictive validity to subsequent early communicative and linguistic skills was examined. METHODS: The participants were 27 Finnish-speaking mothers and their healthy firstborn infants. Maternal and infant interactive behaviour was analysed from 20-min samples of free play collected during home visits at the infants' age of 10 months. At 12 months the children were assessed for their communicative and linguistic skills by using the Finnish version of the MacArthur Communicative Development Inventories and the Communication and Symbolic Behaviour Scales. RESULTS: The frequencies of maternal responses and infant intentional communicative acts were not intercorrelated. As for subsequent communicative and linguistic skills, the results of regression analyses indicated that both maternal responsiveness and infant intentional communication predict early comprehensive skills, whereas expressive skills--the use of both verbal and gestural communicative means--are predicted only by infant intentional communication. CONCLUSION: The results of the present study suggest that maternal responsiveness during the prelinguistic stage is not necessarily dependent on children's communicative competence. As predictors of early communicative and linguistic skills, both maternal responsiveness and infant intentional communication make a distinctive contribution.

Similarities in the phenotype of the auditory neural substrate in children with Asperger syndrome and their parents.

Asperger syndrome (AS) is a developmental disorder of brain function characterized by deficits in social interaction including difficulties in understanding emotional expressions. Children with AS share some of the behavioural characteristics with their parents and AS seems to run particularly in the male members of the same families. The aim of the present study was to determine whether similarities could be found between children with AS and their parents at central auditory processing. It was found that in children with AS the sound encoding, as reflected by the exogenous components of event-related potentials, was similarly abnormal as in both their mothers and fathers. However, their abnormal cortical auditory discrimination, as indexed by the prolonged latency of the mismatch negativity, resembled that of their fathers but not that of their mothers. The present results suggest that complex genetic mechanisms may contribute to auditory abnormalities encountered in children with AS.

Is a large family a protective factor against behavioural and emotional problems at the age of 8 years?

AIM: To study the prevalence of behavioural and emotional problems among children from different family types, sibship size and birth order. METHODS: A prospective birth cohort (n = 9357) study where parents filled in two questionnaires and teachers assessed children's behaviour using the Rutter scale (RB2). RESULTS: 14.3% scored above the cut-off point (RB2 > or = 9) indicating probable psychiatric disturbance, boys more often than girls (OR 2.6, 95% CI 2.3-3.0). Behavioural problems (9.2%) were more common than emotional ones (4.1%). Boys living in families other than two-parent families were at risk for probable psychiatric disturbance, and a corresponding risk was observed for girls living in single-parent or always one-parent families. Other than two-parent family was also a risk for behavioural problems; for boys adjusted odds ratios ranged significantly from 1.8 to 2.4 and for girls from 2.0 to 3.7. "Only children" had the highest prevalence of behavioural problems, while children in very large families had the lowest. Living in a very large family was a protective factor against behavioural problems among boys but not among girls. Eldest children were at lower risk of behavioural problems than the other children. The single-parent and always one-parent family was associated with higher risk of emotional problems among girls. CONCLUSION: Children's psychiatric problems are manifested at school mostly as behavioural problems. A two-parent family and being the oldest in the sibling series seem to be protective factors. Very large family size, if not connected to social disadvantages, does not seem to be a risk factor for children's behaviour.

Total plasma l-tryptophan, free l-tryptophan and competing amino acid levels in a homicidal male adolescent with conduct disorder.

OBJECTIVE: Several studies have shown abnormal findings in human serotonin metabolism, such as increased total plasma l-tryptophan and free l-tryptophan levels among habitually violent antisocial offenders. It is not clear if these increased l-tryptophan levels are associated with adult antisocial personality disorder (ASP) or history of substance abuse, or if these levels are already present in adolescent subjects with conduct disorder (CD). METHOD: Total plasma and free l-tryptophan and competing amino acids (CAAs) were measured in a 15-year-old adolescent offender, who was convicted for two homicides, and in 10 healthy male controls of similar age and body mass index (BMI). RESULTS: In the juvenile offender, plasma total l-tryptophan/CAA was 84% and free l-tryptophan/CAA 143% higher than average mean among controls. CONCLUSION: From this very aggressive boy with CD, findings of free l- and total l-tryptophan/CAA values were similar to those of habitually violent adult ASP offenders. As severe CDs in adolescence tend to develop into adults with ASP, increased l-tryptophan/CAA and free l-tryptophan/CAA values may serve as early indicators for the development of habitually violent adult offenders.

Poor sleep and psychiatric symptoms at school: an epidemiological study.

The objective of this study was to evaluate associations between sleep problems and psychiatric symptoms at school. A random sample consisting of 5813 eight- to nine-year-old children was selected from ordinary schools. Both parents' and children's reports of sleep problems were taken into account. The psychiatric symptoms were addressed according to the teachers' reports (the Rutter Scale B). Children with severe sleep problems were more likely to have a psychiatric disturbance according to the Rutter B Scale (OR 2.45, 95% CI 1.85-3.25). Logistic regression models showed that severe sleep problems were highly associated with emotional problems (OR 2.74, 95% CI 1.84-4.13), school attendance problems (OR 2.53, 95% OR 1.45-4.41), behavioural problems (OR 2.44, 95% CI 1.59-3.75) and hyperactivity (OR 2.02, 95% CI 1.30-3.13). Over 95% of severe sleep problems were reported only by the children themselves. In conclusion, children with severe sleep problems have substantially more teacher-reported psychiatric symptoms than those with no or mild sleep complaints. In diagnosing sleep disorders, it is important to include children as informants because relevant information may be overlooked when only parents are questioned.

Predictors of delayed social maturation and mental health disorders in young adults chronically ill since childhood.

To ascertain the influence of juvenile-onset chronic physical diseases and associating factors of social environment on delayed social maturation and mental health disorders in young adults, we analysed a group of 407 (184 female, 223 male) subjects with these conditions and compared the results with those of 123 (63 female, 60 male) healthy controls studied at the age of 19-25 years. The social maturation index was formed on the basis of a demographic interview, which also reviewed the state of social development and the family situation during childhood. Mental health disorders were assessed with a Present State Examination (PSE) interview analysed with the CATEGO program. With regard to social maturation at least half of the patients and controls were doing well, whereas for 29% (CI(95), 25%-33%) of the patients and 17% (CI(95), 10%-24%) of the controls the index showed delayed maturation. Subjects with poor social maturation were found most often among the disabled patients but also among the patients without severe diseases. The prevalence of PSE-CATEGO-identified psychiatric syndromes was equal in the patients and the controls (22% versus 20%). However, the patients with severe or disabling diseases had more severe psychiatric syndromes. The prevalences of depressive syndromes were also equal, but the depression of the patients was more often a profound affective disorder. Male sex, poor scholastic and vocational success, and social problems in the family during childhood were significantly associated with poor social maturation. On the other hand, the most significant predictors of mental health problems in young adults were female sex, family distress during childhood, and a severe disease. Juvenile-onset physical disease was considered to delay social maturation in some subjects and to deepen or modulate the clinical picture of mental health disorders. It is concluded that juvenile-onset physical diseases combined with family-related factors affect in different ways the social growth and psychiatric well-being. The results suggest that the subjects with chronic diseases during childhood should be thoroughly assessed by a child psychiatrist to evaluate the orientation of psychological development and the impact of the child's disease on the family and to ensure balanced psychological and social growth.

Somatically expressed psychological distress and alexithymia in adolescence--reflecting unbearable emotions?

The characteristics of five 11- to 15-year-old patients with somatic symptoms and alexithymia in conjunction with psychological distress are reported. The findings are compared with the existing literature. Preceding somatic disorders and difficulties at school and in peer relationships were found. Family violence was evident in two cases. We postulate that the developmental tasks of adolescence were complicated by the threat of disability, disease, and death. The parents were incapable of expressing their feelings either in general or because of their recent traumatic experiences. Our findings suggest that unbearable emotions often precede the combination of preadolescent and adolescent alexithymia and somatization in clinically relevant cases.

Autism in Northern Finland.

Recent research reports show that autistic spectrum disorders may actually be more common than previously believed. General awareness and clinical knowledge of these disorders have increased, and the criteria in the ICD-10 and the DSM-IV are also now more detailed. The diagnostic criteria and the methods of ascertainment influence the prevalence. The age specific incidence obtained in this study showed the cumulative incidence to be lowest, 6.1 per 10,000, in the oldest age group of 15- to 18-year-old children, and highest, 20.7 per 10,000, in the age group of 5-7 year-olds, when the criteria of the ICD-10 and the DSM-IV were used. In this study, almost 50% of the autistic cases had a tested IQ above 70. The degree of autism, as assessed by the Childhood Autism Rating Scale (CARS), varied from mild autistic features in 8.5% through moderate in 58.5% to severe in 33.0%.