Practitioner review: early adversity and developmental disorders

Cumulative Prenatal Risk Factors and Developmental Coordination Disorder in Young Children

OBJECTIVES

To examine the effect of cumulative prenatal risk factors (RFs) on the presence of Developmental Coordination Disorder (DCD) in young children.

METHODS

Participants (N = 589, 338 boys, Mage = 4.5 ± 0.5 years) were from a larger cohort study, the Coordination and Activity Tracking in Children (CATCH). Motor coordination was assessed using the Movement Assessment Battery for Children- 2nd Edition. Children were classified as at risk for DCD (DCDr) based on European Academy of Childhood Disability guidelines. RFs were obtained through a parent-completed survey. A multiple logistic regression was conducted to examine the effect of the RFs on DCD.

RESULTS

Results showed that the odds of a child having DCDr are significantly higher with a greater total number of prenatal RFs, after adjustment for mother's age at child's birth, child's sex, child's age, marital status and total annual household income (OR = 1.48, p < 0.01).

CONCLUSIONS

These findings warrant further investigation into the cumulative impact of multiple prenatal RFs and whether specific combinations of RFs might be more strongly linked to DCD than others. These results provide additional insight into possible causes and prevention of DCD.

Social engagement and allostatic load mediate between adverse childhood experiences and multimorbidity in mid to late adulthood: the Canadian Longitudinal Study on Aging

BACKGROUND

Adverse childhood experiences (ACEs) are associated with multimorbidity in adulthood. This link may be mediated by psychosocial and biological factors, but evidence is lacking. The current study evaluates this mediation model.

METHOD

We analyzed data from the Canadian Longitudinal Study of Aging (N = 27 170 community participants). Participants were 45-85 years at recruitment, when allostatic load and social engagement data were collected, and 3 years older at follow-up, when ACEs and multimorbidity data were collected. Structural equation modeling was used to test for mediation in the overall sample, and in sex- and age-stratified subsamples, all analyses adjusted for concurrent lifestyle confounds.

RESULTS

In the overall sample, ACEs were associated with multimorbidity, directly, β = 0.12 (95% confidence interval 0.11-0.13) and indirectly. Regarding indirect associations, ACEs were related to social engagement, β = -0.14 (-0.16 to -0.12) and social engagement was related to multimorbidity, β = -0.10 (-0.12 to -0.08). ACEs were related to allostatic load, β = 0.04 (0.03-0.05) and allostatic load was related to multimorbidity, β = 0.16 (0.15-0.17). The model was significant for males and females and across age cohorts, with qualifications in the oldest stratum (age 75-85).

CONCLUSIONS

ACEs are related to multimorbidity, directly and via social engagement and allostatic load. This is the first study to show mediated pathways between early adversity and multimorbidity in adulthood. It provides a platform for understanding multimorbidity as a lifespan dynamic informing the co-occurrence of the varied disease processes represented in multimorbidity.

Early adversity and positive parenting: Association with cognitive outcomes in children with autism spectrum disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social communication and repetitive behaviors. Children with ASD are statistically more likely to experience early adversity; however, little is known about the types of early adversity that place these children at risk, the role of parenting as a protective factor, and how this early life stress impacts cognitive outcomes. We assessed early adversity in 302 children (ASD = 98) aged 6-16 years old, using parent-based report. To identify protective factors, we assessed parenting styles using parent surveys. Executive functions were assessed in the children using the WISC-V. Children with ASD had an increased incidence of familial stressors compared to the typically developing (TD) group. Positive parenting was associated with a significant decrease in the incidence of familial adverse events for both children with ASD and TD children. Examining the relationship between adversity and cognitive outcomes, in young children (6-11 years) with ASD, environmental stressors were associated with cognitive impairments. Findings suggest children with ASD may be at higher risk for familial adversity than their TD peers. However, all children benefit from positive parenting styles, which may mitigate the adverse effects of family-based early life stress. LAY SUMMARY: Some key features of Autism Spectrum Disorder (ASD) include difficulties with communication and social impairments. This means that children with ASD may be more likely to experience early adversity (stressful social interactions which take place during childhood) than children without ASD. Research in typically developing (TD) children has shown that experiencing more stressful events in childhood can cause changes in the brain, which can potentially impact the child's memory, reasoning, and decision-making skills later in life. However, there is evidence to suggest that having a nurturing relationship with a parent can offset some of the negative impacts of childhood adversity. In our study, we found that children with ASD are more likely to experience family-related stress compared to TD children. Having a positive relationship with a parent, however, was linked to experiencing this type of stress less often for all children, regardless of whether they were diagnosed with ASD. We also found that stressors related to environmental factors like financial instability were associated with lower cognitive abilities in children with ASD under 12 years of age. Understanding how these factors interact and differ in children with ASD can help to build stronger families and help children with ASD to thrive throughout their development.

The burdened life of adults with ADHD: Impairment beyond comorbidity

Since approximately 70% of adult patients with attention-deficit/hyperactivity disorder (ADHD) have at least one comorbid disorder, rating of impairment specifically attributable to ADHD is a hard task. Despite the evidence linking environmental adversities with negative outcomes in ADHD, life events measures have not been used to rate the disorder impairment. The present study tested for the first time the hypothesis that increased ADHD severity is associated with an increase in negative recent life events, independently of comorbidity status. The psychiatric diagnoses of 211 adult ADHD outpatients were based on DSM-IV criteria assessed through structured interviews (K-SADS-E for ADHD and ODD, MINI for ASPD and SCID-IV-R for other comorbidities). ADHD severity was evaluated with the Swanson, Nolan and Pelham rating scale (SNAP-IV) and recent life events with the Life Experience Survey. Higher SNAP-IV inattention and hyperactivity scores, female gender, lower socioeconomic status and the presence of comorbid mood disorders were associated with negative life events. Poisson regression models with adjustment for possible confounders confirmed the effect of inattention and hyperactivity severity on negative life events. Our results suggest that the negative life events experienced by these patients are associated to the severity of ADHD independently from comorbid psychiatric disorders.

Attention-Deficit Hyperactivity Disorder (ADHD) Symptoms in Children Adopted from Poland and their Atypical Association Patterns: a Bayesian Approach

Although high rates of attention-deficit hyperactivity disorder (ADHD) symptoms have been observed among internationally adopted children, research on these symptoms in Polish adoptees is lacking. Therefore, we examined ADHD symptoms in Polish adoptees and their relationship to pre-adoptive risk factors, that is, time in institutional care, early deprivation, and prenatal alcohol exposure. We further compared the association patterns and gender distribution of ADHD symptoms in children adopted from Poland to those reported in the literature for ADHD symptoms in non-adopted children. Dutch adoptive parents of 121 Polish adoptees (52% boys; M age = 10.9 years, range 6.2-15.6; M ageadoption = 3.0 years, range 0.8-6.9) completed questionnaires regarding ADHD symptoms, pre-adoptive risk factors, attachment problems, conduct problems, and executive functioning deficits. Bayesian evaluation of informative hypotheses showed that Polish adoptees had increased levels of ADHD symptoms, compared to Dutch children in the general population. Time in institutional care, early deprivation, and prenatal alcohol exposure were not associated with ADHD symptoms. ADHD symptoms in Polish adoptees were more strongly associated with attachment problems and executive functioning deficits, but less strongly with conduct problems, compared to ADHD symptoms in non-adoptees. Furthermore, ADHD symptoms were more equally distributed among boys and girls than they are in non-adopted children. The findings indicate that Polish adoptees and their adoptive parents need special attention and support. The dissimilarities between ADHD symptoms in Polish adoptees and non-adoptees might indicate a different underlying causal mechanism, which may have important implications for clinical practice.

Perinatal hypoxia as a risk factor for psychopathology later in life: the role of dopamine and neurotrophins

Brain development is influenced by various prenatal, intrapartum, and postnatal events which may interact with genotype to affect the neural and psychophysiological systems related to emotions, specific cognitive functions (e.g., attention, memory), and language abilities and thereby heighten the risk for psychopathology later in life. Fetal hypoxia (intrapartum oxygen deprivation), hypoxia-related obstetric complications, and hypoxia during the early neonatal period are major environmental risk factors shown to be associated with an increased risk for later psychopathology. Experimental models of perinatal hypoxia/ischemia (PHI) showed that fetal hypoxia-a consequence common to many birth complications in humans-results in selective long-term disturbances of the dopaminergic systems that persist in adulthood. On the other hand, neurotrophic signaling is critical for pre- and postnatal brain development due to its impact on the process of neuronal development and its reaction to perinatal stress. The aim of this review is (a) to summarize epidemiological data confirming an association of PHI with an increased risk of a range of psychiatric disorders from childhood through adolescence to adulthood, (b) to present immunohistochemical findings on human autopsy material indicating vulnerability of the dopaminergic neurons of the human neonate to PHI that could predispose infant survivors of PHI to dopamine-related neurological and/or cognitive deficits in adulthood, and

Clinical, Sociobiological, and Cognitive Predictors of ADHD Persistence in Children Followed Prospectively Over Time

With increasing awareness that ADHD is chronically disabling, a burgeoning literature has examined childhood clinical indicators of ADHD persistence. This study investigates whether childhood factors reflecting biological risk and cognitive reserve have additive predictive value for the persistence of ADHD that is unique beyond childhood indicators of disorder severity. One-hundred thirty children with ADHD (mean age = 8.9 years, 75 % male) were followed into adolescence (mean age = 14.0 years). Childhood ADHD and co-morbidities were assessed via interviews with parents and teachers; parental psychopathology was assessed via parent interview; exposure to neurobiological and psychosocial adversity were indexed by parent questionnaire; and cognitive reserve was evaluated through children's performance on measures of IQ and executive functioning. Univariate analyses identified childhood inattention and hyperactivity-impulsivity, co-morbid oppositional defiant disorder, overall impairment, and paternal anxiety and depression as more prevalent amongst adolescents with persistent compared with remitted ADHD. Only child-level predictors remained significant in a final multivariate model. These results suggest that children who are most likely to experience persistent ADHD have a more severe clinical presentation in childhood, reflected by increased levels of inattention, oppositional behavior, and impairment. They also are more likely to have fathers with internalizing concerns, but these concerns do not uniquely predict ADHD persistence beyond child-level factors. Contrary to expectations, childhood adversity and cognitive functioning did not predict the course of ADHD.

Coordinated movement is influenced by prenatal light experience in bobwhite quail chicks (Colinus virginianus)

Sensory-motor development begins early during embryogenesis and is influenced by sensory experience. Little is known about the prenatal factors that influence the development of motor coordination. Here we investigated whether and to what extent prenatal light experience can influence the development of motor coordination in bobwhite quail hatchlings. Quail embryos were incubated under four light conditions: no light (dark), 2h of total light (2HR), 6h of total light (6HR), and diffused sunlight (controls). Hatchlings were video recording walking down a runway at three developmental ages (12, 24, and 48h). Videos were assessed for forward locomotion, a measurement of motor coordination, falls, a measurement of motor instability, and motivation to complete the task. We anticipated a linear decline of coordination with a reduction in prenatal light experience and improved coordination with age. Furthermore, as motor coordination becomes more laborious we anticipated motivation to complete the task would decline. However, our findings revealed hatchlings did not uniformly improve with age as expected, nor did the reduction of light result in a linear reduction in motor coordination. Instead, we found a more complex relationship with 6HR and 2HR hatchlings showing distinct patterns of stability and instability. Similarly, we found a reduction in motivation within the 6HR light condition. It appears that prenatal light exposure influences the development of postnatal motor coordination and we discuss these finding in light of neurodevelopmental processes influenced by light experience.

The Association Between Socioeconomic Disadvantage and Attention Deficit/Hyperactivity Disorder (ADHD): A Systematic Review

This systematic review examines associations between parental socioeconomic disadvantage and childhood attention deficit/hyperactivity disorder (ADHD). Socioeconomic status (SES) was measured by parental income, education, occupation and marital status. Results were mixed by measure of SES with no one aspect being differentially related to ADHD. 42 studies were included in the review, of which 35 found a significant univariate association between socioeconomic disadvantage and ADHD. Meta-analyses of dimensions of SES and their association with ADHD indicate that children in families of low SES are on average 1.85-2.21 more likely to have ADHD than their peers in high SES families. In spite of substantial between-study heterogeneity, there is evidence for an association between socioeconomic disadvantage and risk of ADHD measured in different ways. This is likely mediated by factors linked to low SES such as parental mental health and maternal smoking during pregnancy.

Disruptions of working memory and inhibition mediate the association between exposure to institutionalization and symptoms of attention deficit hyperactivity disorder

BACKGROUND

Young children raised in institutions are exposed to extreme psychosocial deprivation that is associated with elevated risk for psychopathology and other adverse developmental outcomes. The prevalence of attention deficit hyperactivity disorder (ADHD) is particularly high in previously institutionalized children, yet the mechanisms underlying this association are poorly understood. We investigated whether deficits in executive functioning (EF) explain the link between institutionalization and ADHD.

METHOD

A sample of 136 children (aged 6-30 months) was recruited from institutions in Bucharest, Romania, and 72 never institutionalized community children matched for age and gender were recruited through general practitioners' offices. At 8 years of age, children's performance on a number of EF components (working memory, response inhibition and planning) was evaluated. Teachers completed the Health and Behavior Questionnaire, which assesses two core features of ADHD, inattention and impulsivity.

RESULTS

Children with history of institutionalization had higher inattention and impulsivity than community controls, and exhibited worse performance on working memory, response inhibition and planning tasks. Lower performances on working memory and response inhibition, but not planning, partially mediated the association between early institutionalization and inattention and impulsivity symptom scales at age 8 years.

CONCLUSIONS

Institutionalization was associated with decreased EF performance and increased ADHD symptoms. Deficits in working memory and response inhibition were specific mechanisms leading to ADHD in previously institutionalized children. These findings suggest that interventions that foster the development of EF might reduce risk for psychiatric problems in children exposed to early deprivation.

Maternal alcohol consumption

Background Despite decades of research, the aetiology of attention deficit disorder with hyperactivity (ADHD) remains largely unknown. Next to a strong genetic component, increasing evidence suggests additional adverse impact of environmental factors, two of which have, although controversially, withstood meta-analysis: gestational exposure to smoking (OR 2.39) and low birth weight (OR 2.64). Several studies have investigated a possible association between prenatal exposure to alcohol and ADHD, although the matter is complicated due to foetal alcohol syndrome disorders (FASD) with ADHD-like symptoms. Questions Can an estimate of the effect of gestational exposure to alcohol for ADHD be determined? What is the relevance of primary care services in screening and intervention in mild to moderate drinking in pregnant women? Method MEDLINE, Cinahl, PsychInfo, EMBASE (1995-2008) were searched for articles in English, supplemented by a manual search. Out of 23 reviewed studies, three were included in the metaanalysis; one further study was added to undertake a sub-analysis comparing severe versus mild alcohol consumption. Summary odds ratios (OR) were extracted and fixed/random-effects meta-analysis were used for combining the OR's. Heterogeneity across the studies was formally assessed using Cochran's Q. Results An OR of 2.33 (95% CI, 1.18-4.61), (z = 2.43, p = 0.02) suggests that exposed children are 2.33 times more likely to have ADHD than non exposed children. Discussion Our meta-analysis suggests that children exposed to alcohol during pregnancy are at risk for ADHD. However, evidence is sparse and it remains uncertain whether a causal association exists. Further research is needed into dose-response relationship, timing of exposure, influence of genetic factors involved in maternal alcohol abuse and the role of FASD in ADHD-like symptoms. If a detrimental effect of mild to moderate drinking on the offspring is supported by stronger evidence, primary care services could have a major role in prevention and early intervention. This would be in addition to their already established role in helping heavy drinking mothers.

Maternal repeated oral exposure to microcystin-LR affects neurobehaviors in developing rats

Microcystins are toxic peptides secreted by certain water blooms of toxic cyanobacteria. The most widely studied microcystin is microcystin-LR (MC-LR), which exhibits hepatotoxicity and neurotoxicity. However, limited information is available regarding the effects on offspring following maternal exposure. The present study was conducted to observe the effects of progestational exposure to MC-LR on postnatal development in rats. Female Sprague-Dawley rats (28 d old) were randomly divided into a control group and 3 treatment groups (1.0 µg MC-LR/kg body wt, 5.0 µg MC-LR/kg body wt, and 20.0 µg MC-LR/kg body wt), with 7 rats per group. The MC-LR was administered through gavage once every 48 h for 8 wk. Pure water was used as control. Each female rat was mated with an unexposed adult male rat. Motor development, behavioral development, and learning ability of pups were detected using surface righting reflex, negative geotaxis, and cliff avoidance tests on postnatal day 7. Open-field and Morris water maze tests were performed on postnatal day 28 and day 60. The levels of lipid peroxidation products and antioxidant indices in the rat hippocampus were also detected. Pups from the MC-LR-treated groups had significantly lower scores than controls in the cliff avoidance test (p < 0.05). Cognitive impairment, malondialdehyde level, and total superoxide dismutase activity significantly increased in MC-LR-exposed pups compared with controls (p < 0.05). Therefore, the present study reveals that maternal exposure to MC-LR has adverse effects on neurodevelopment in rat offspring.

Epilepsy associated with autism and attention deficit hyperactivity disorder: is there a genetic link?

Autism Spectrum Disorders (ASDs) and Attention Deficit and Hyperactivity Disorder (ADHD) are the most common comorbid conditions associated with childhood epilepsy. The co-occurrence of an epilepsy/autism phenotype or an epilepsy/ADHD phenotype has a complex and heterogeneous pathogenesis, resulting from several altered neurobiological mechanisms involved in early brain development, and influencing synaptic plasticity, neurotransmission and functional connectivity. Rare clinically relevant chromosomal aberrations, in addition to environmental factors, may confer an increased risk for ASDs/ADHD comorbid with epilepsy. The majority of the candidate genes are involved in synaptic formation/remodeling/maintenance (NRX1, CNTN4, DCLK2, CNTNAP2, TRIM32, ASTN2, CTNTN5, SYN1), neurotransmission (SYNGAP1, GABRG1, CHRNA7), or DNA methylation/chromatin remodeling (MBD5). Two genetic disorders, such as Tuberous sclerosis and Fragile X syndrome may serve as models for understanding the common pathogenic pathways leading to ASDs and ADHD comorbidities in children with epilepsy, offering the potential for new biologically focused treatment options.

Is there an association between perinatal complications and attention-deficit/hyperactivity disorder-inattentive type in children and adolescents?

OBJECTIVE

The objective of the present study is to investigate the association between attention deficit/hyperactivity disorder (ADHD), predominantly inattentive type (ADHD-I) and prenatal, delivery and early postnatal complications (PDPC).

METHOD

In a case-control design, we assessed a sample of 124 children and adolescents with ADHD-I and 124 non-ADHD controls (6-17 years old) from both a non-referred (n = 200) and a clinical sample (n = 48). Cases and controls, matched by gender and age, were systematically evaluated through structured diagnostic interviews. Prenatal, delivery and early postnatal complications (PDPC), as well as potential confounders were evaluated by direct interview with biological mothers.

RESULTS

Conditional logistic regression analysis showed that children and adolescents whose mothers presented more PDPC had a significantly higher risk for ADHD-I (p = 0.005; OR = 1.25; CI 95%: 1.1-1.5).

CONCLUSIONS

In a case-control study, we expanded to ADHD-I previous findings suggesting the association between perinatal factors and broadly defined ADHD. Due to the preventable nature of some of these PDPC, our results have clear impact in public mental health policies.

Peripubertal viral-like challenge and social isolation mediate overlapping but distinct effects on behaviour and brain interferon regulatory factor 7 expression in the adult Wistar rat

A range of adverse, early life environmental influences such as viral infection and social deprivation are thought to increase risk of psychiatric illness later in life. Here, we used peripheral administration of the viral infection mimic polyriboinosinic-polyribocytidylic acid (polyI:C) to compare the consequences of peripubertal infection and isolation rearing. Isolation rearing induced deficits in sensorimotor gating and recognition memory while no changes in social interaction or spatial learning were observed. PolyI:C injection during the peripubertal period markedly increased expression of interferon-stimulated genes (Ifit2, Prkr, Mx2 and Irf7) in the hippocampal dentate gyrus demonstrating that peripheral administration of the viral mimic in the adolescent animal does have direct effects in the brain. Peripubertal infection mimicry induced a similar but later emerging behavioural deficit in prepulse inhibition implying the existence of a peripubertal window of opportunity for viral-mediated cytokine increases to impact brain development and function. PolyI:C treatment also impaired novel object recognition but did not alter spatial reference memory or social interaction. Combining the polyI:C challenge with social isolation did not exacerbate the behavioural deficits seen with isolation rearing alone. Using Irf7 as a marker, peripubertal viral infection mimicry, isolation rearing and a combination of both were all seen to produce a long-lasting molecular imprint on the interferon-associated signalling pathway in the principal neuron population of the hippocampal dentate gyrus. The data suggest that the sensitivity of brain structure and function to disruption by viral infection extends into the peripubertal period. Moreover, augmented interferon signalling in hippocampus may represent a common molecular imprint of environmental insults associated with neuropsychiatric illnesses like schizophrenia.

Prenatal exposure to cigarette smoke or alcohol and cerebellum volume in attention-deficit/hyperactivity disorder and typical development

Prenatal exposure to teratogenic substances, such as nicotine or alcohol, increases the risk of developing attention-deficit/hyperactivity disorder (ADHD). To date, studies examining this relationship have used symptom scales as outcome measures to assess the effect of prenatal exposure, and have not investigated the neurobiological pathways involved. This study explores the effect of prenatal exposure to cigarettes or alcohol on brain volume in children with ADHD and typically developing controls. Children with ADHD who had been exposed prenatally to either substance were individually matched to children with and without ADHD who had not been. Controls who had been exposed prenatally were also individually matched to controls who had not been. For prenatal exposure to both smoking and alcohol, we found a pattern where subjects with ADHD who had been exposed had the smallest brain volumes and unexposed controls had the largest, with intermediate volumes for unexposed subjects with ADHD. This effect was most pronounced for cerebellum. A similar reduction fell short of significance for controls who had been exposed to cigarettes, but not alcohol. Our results are consistent with an additive effect of prenatal exposure and ADHD on brain volume, with the effects most pronounced for cerebellum.

Management of attention-deficit/hyperactivity disorder: the importance of psychosocial and medication treatments

Attention-deficit/hyperactivity disorder (ADHD) assessment and treatment in children and adolescents is complex. Key biological and psychosocial risk factors need to be identified and treated because of their potential mediating interaction that affect the onset, progression, and psychosocial and medication treatment response of core ADHD symptoms and common associated co-morbid conditions. Both psychosocial and medication treatments, alone and in combination, have been shown to reduce the core ADHD symptoms and those of its key co-morbid disorders. Yet, to date, the potential synergism between targeted and specific medication and psychosocial treatments remains poorly understood and under-researched. Interestingly, recent positron emission tomography findings emphasise the importance of contextual salience and positive reinforcement strategies for stimulant medication, the primary medication treatment for ADHD, to have its effect. This is not surprising, given recent epigenetic models of gene-environment interaction that are revolutionising our understanding of developmental disorders like ADHD. This annotation briefly outlines the emerging evidence that supports the role of psychosocial treatment alongside medication treatment in the management of ADHD. Future significant clinical directions are noted.

Quick, simple measures of family relationships for use in clinical practice and research. A systematic review

BACKGROUND

Family functioning has been implicated in the onset of child and adult psychopathology. Various measures exist for assessing constructs in the areas of parent-child relationships, parental practices and discipline, parental beliefs, marital quality, global family functioning and situation-specific measures.

OBJECTIVES

To identify systematically all questionnaire measures of family functioning appropriate for use in primary care and research.

METHODS

A systematic literature review was conducted, following PRISMA guidelines and searching 14 bibliographic databases using pre-determined filters, to identify family functioning measures suitable for use in families with children from 0 to 3 years old.

RESULTS

One hundred and seven measures of family functioning were reported and tabulated and the most commonly used measures were identified.

CONCLUSIONS

There are numerous measures available demonstrating characteristics, which make them suitable for continued use. Future research is needed to examine the more holistic measurement of family functioning using integration of multi-informant data.

Discrimination between attention deficit hyperactivity disorder and reactive attachment disorder in school aged children

We aimed to determine whether it is possible to discriminate between children with attention deficit hyperactivity disorder (ADHD) and children with reactive attachment disorder (RAD) using standardized assessment tools for RAD. The study involved 107 children: 38 with a diagnosis of RAD and 30 with ADHD were recruited through community child and adolescent mental health services (CAMHS) and specialist ADHD clinics. In addition, 39 typically developing children were recruited through family practice. Clinicians were trained to use a standardized assessment package for RAD using a DVD with brief follow-up support. Discriminant function analysis was used to identify the items in the standardized assessment package that best discriminated between children with ADHD and children with RAD. Clinicians' ratings of RAD symptoms were reliable, particularly when focusing on eight core DSM-IV symptoms of RAD. Certain parent-report symptoms were highly discriminatory between children with ADHD and children with RAD. These symptoms included "cuddliness with strangers" and "comfort-seeking with strangers". A semi-structured interview with parents, observation of the child in the waiting room and teacher report of RAD symptoms aided diagnostic discrimination between the groups. Clinical diagnosis of RAD can be made reliably by clinicians, especially when focusing on eight core RAD symptoms. Clear discrimination can be made between children with RAD and children with ADHD.

A comparison of family adversity and family dysfunction in families of children with attention deficit hyperactivity disorder (ADHD) and families of children without ADHD

PURPOSE

This study examined the presence of family adversity and family dysfunction in 32 families who had children diagnosed with attention deficit hyperactivity disorder (ADHD) compared with 23 families with similar sociodemographic characteristics whose children did not have ADHD.

DESIGN AND METHODS

A descriptive comparative design was used to investigate family adversity and family dysfunction.

RESULTS

Families of children with ADHD had significantly higher levels of family dysfunction than families whose children did not have ADHD.

PRACTICE IMPLICATIONS

Earlier identification and intervention with families of children who have ADHD may result in healthier family and child outcomes.

The neurobiological basis of ADHD

Attention-Deficit/Hyperactivity Disorder is not a single pathophysiological entity and appears to have a complex etiology. There are multiple genetic and environmental risk factors with small individual effect that act in concert to create a spectrum of neurobiological liability. Structural imaging studies show that brains of children with Attention-Deficit/Hyperactivity Disorder are significantly smaller than unaffected controls. The prefrontal cortex, basal ganglia and cerebellum are differentially affected and evidence indicating reduced connectivity in white matter tracts in key brain areas is emerging. Genetic, pharmacological, imaging, and animal models highlight the important role of dopamine dysregulation in the neurobiology of Attention-Deficit/Hyperactivity Disorder. To date, stimulants are the most effective psychopharmacological treatments available for Attention-Deficit/Hyperactivity Disorder. Currently only immediate release methylphenidate and atomoxetine are approved for the treatment of ADHD in Italy. Drug treatment should always be part of a comprehensive plan that includes psychosocial, behavioural and educational advice and interventions.

Predicting the unpredictable? Identifying high-risk versus low-risk parents with intellectual disabilities

OBJECTIVES

This study set out to identify risk factors affecting parents with intellectual disabilities (IDs) by determining: (i) whether perception of family support differs between parents with IDs, referring professionals, and a specialist parenting service; (ii) whether multivariate familial and demographic factors differentiates 'high-risk' from 'low-risk' parenting; and (iii) the impact of partner relationships on parental competency and risk status.

METHODS

Secondary data analysis was conducted on data gathered from 101 parents with IDs and 172 of their children, all of whom had been referred to a specialist parenting service over a 5 year period.

RESULTS

Cross-tabulations were applied to the data to examine causal processes and to improve general understanding of the risks associated with families. Contrary to popular expectations IQ levels of the main parent, relationship status, parental age, employment, amenities, valued support and parents' perception of need were not identified as contributory factors distinguishing 'high-risk' from 'low-risk' parents. Instead, 'high-risk' parenting associated more with parental reports of childhood trauma (emotional abuse and physical neglect in particular), parents' having additional special needs in addition to their IDs or parents who were raising a child with special needs. Other 'high-risk' factors identified related to the male partners of mothers with IDs, many of whom did not have IDs and/or whose histories included anti-social behaviors or criminality.

CONCLUSIONS

The study identified some high-risk variables among parents with IDs that can distinguish them from low-risk parents with IDs.

PRACTICE IMPLICATIONS

These findings generate challenges for agencies who attempt to capture the needs of parents with IDs and who endeavour to provide services to families deemed to be "at risk." These outcomes will be of special interest to the courts, especially when parents with IDs are involved in care proceedings.

Developmental phenotypes and causal pathways in attention deficit/hyperactivity disorder: potential targets for early intervention?

Early intervention approaches have rarely been implemented for the prevention of attention deficit/hyperactivity disorder (ADHD). In this paper we explore whether such an approach may represent an important new direction for therapeutic innovation. We propose that such an approach is most likely to be of value when grounded in and informed by developmental models of the dynamic, complex and heterogeneous nature of the condition. First, we set out a rationale for early intervention grounded in the science of ADHD viewed through developmental models. Second, we re-examine the concept of disorder-onset from the perspective of developmental trajectories and phenotypes. Third, we examine potential causal pathways to ADHD with regard to originating risk, pathophysiological mediators, environmental moderators and developmental continuities. Finally, we explore the potential value of strategies for identifying young children at risk for ADHD, and implementing interventions in ways that can target these underlying pathogenic processes. The utility of such an approach represents an important area for future research but still requires 'proof of concept'. Therefore prior to widespread clinical implementation, far greater knowledge is required of (i) developmental pathways into ADHD, (ii) the value of identifying neuropsychological mediators of these pathways, and (iii) the extent to which targeting mediating mechanisms will improve treatment outcomes for children with ADHD.

The evolution of hyperactivity, impulsivity and cognitive diversity

The evolutionary status of attention deficit/hyperactivity disorder (ADHD) is central to assessments of whether modern society has created it, either physically or socially; and is potentially useful in understanding its neurobiological basis and treatment. The high prevalence of ADHD (5-10%) and its association with the seven-repeat allele of DRD4, which is positively selected in evolution, raise the possibility that ADHD increases the reproductive fitness of the individual, and/or the group. However, previous suggestions of evolutionary roles for ADHD have not accounted for its confinement to a substantial minority. Because one of the key features of ADHD is its diversity, and many benefits of population diversity are well recognized (as in immunity), we study the impact of groups' behavioural diversity on their fitness. Diversity occurs along many dimensions, and for simplicity we choose unpredictability (or variability), excess of which is a well-established characteristic of ADHD.Simulations of the Changing Food group task show that unpredictable behaviour by a minority optimizes results for the group. Characteristics of such group exploration tasks are risk-taking, in which costs are borne mainly by the individual; and information-sharing, in which benefits accrue to the entire group. Hence, this work is closely linked to previous studies of evolved altruism.We conclude that even individually impairing combinations of genes, such as ADHD, can carry specific benefits for society, which can be selected for at that level, rather than being merely genetic coincidences with effects confined to the individual. The social benefits conferred by diversity occur both inside and outside the 'normal' range, and these may be distinct. This view has the additional merit of offering explanations for the prevalence, sex and age distribution, severity distribution and heterogeneity of ADHD.

ADHD as a (non) allergic hypersensitivity disorder: a hypothesis

Research data concerning the causal association between attention deficit hyperactivity disorder (ADHD) and allergies are conflicting. Allergic disorders, like asthma and eczema are clinical syndromes in which both genetic predisposition and environmental factors (pets, pollen and foods) contribute to its development. The hypothesis of ADHD, in some children also being an allergic disorder, is postulated based on comparison of the mechanisms underlying the development of ADHD and allergic disorders. According to the accepted terminology, ADHD may comply with the criteria of hypersensitivity, allergy and atopy. This hypothesis has to be thoroughly tested by randomized controlled trials using environmental triggers and immunologic research. As genes related to the immune system may be associated with ADHD, further genetic research is compulsory. Immunotherapeutic approaches, using immunotherapy and probiotics, can subsequently be implicated in the treatment of ADHD. If hypersensitivity to environmental stimuli like foods contributes to the development of ADHD, the assessment and treatment of ADHD will have to be reconsidered, thereby improving the quality of care for these patients.

Obstetric complications and mild to moderate intellectual disability

BACKGROUND

Mild to moderate intellectual disability affects 2.5% of the general population and is associated with an increased risk of several psychiatric disorders. Most cases are of unknown aetiology although genetic factors have an important role.

AIMS

To investigate the role of obstetric and neonatal complications in the aetiology of mild to moderate intellectual disability.

METHOD

Obstetric and neonatal complications recorded at the time of pregnancy and delivery were compared between participants with mild to moderate intellectual disability, age-matched siblings and unrelated controls using logistic regression.

RESULTS

Admission to a special care baby unit and not being breastfed on discharge were more common in people with mild to moderate intellectual disability. Not being breastfed on discharge was also more common in those with intellectual disability than unaffected siblings. Foetal distress was more common among controls than among those with mild to moderate intellectual disability.

CONCLUSIONS

Admission to a special care baby unit and not being breastfed on discharge may be related to the aetiology of intellectual disability, although the direction of this association is unclear.

A randomised controlled trial into the effects of food on ADHD

The aim of this study is to assess the efficacy of a restricted elimination diet in reducing symptoms in an unselected group of children with Attention deficit/hyperactivity disorder (ADHD). Dietary studies have already shown evidence of efficacy in selected subgroups. Twenty-seven children (mean age 6.2) who all met the DSM-IV criteria for ADHD, were assigned randomly to either an intervention group (15/27) or a waiting-list control group (12/27). Primary endpoint was the clinical response, i.e. a decrease in the symptom scores by 50% or more, at week 9 based on parent and teacher ratings on the abbreviated ten-item Conners Scale and the ADHD-DSM-IV Rating Scale. The intention-to-treat analysis showed that the number of clinical responders in the intervention group was significantly larger than that in the control group [parent ratings 11/15 (73%) versus 0/12 (0%); teacher ratings, 7/10 (70%) versus 0/7 (0%)]. The Number of ADHD criteria on the ADHD Rating Scale showed an effect size of 2.1 (cohen's d) and a scale reduction of 69.4%. Comorbid symptoms of oppositional defiant disorder also showed a significantly greater decrease in the intervention group than it did in the control group (cohens's d 1.1, scale reduction 45.3%). A strictly supervised elimination diet may be a valuable instrument in testing young children with ADHD on whether dietary factors may contribute to the manifestation of the disorder and may have a beneficial effect on the children's behaviour.

ADHD and the rise in stimulant use among children

Attention-deficit/hyperactivity disorder (ADHD) holds the distinction of being the most extensively studied pediatric mental disorder and one of the most controversial, in part because it is also the most commonly diagnosed mental disorder among minors. Currently, almost 8% of youth aged 4 to 17 years have a diagnosis of ADHD, and approximately 4.5% both have the diagnosis and are using a stimulant (methylphenidate or amphetamine) as treatment for the disorder. Yet a diagnosis of ADHD is not simply a private medical finding; it carries with it a host of policy ramifications. The enduring controversy over ADHD in the public arena therefore reflects the discomfort over what happens when science is translated into policies and rules that govern how children will be treated medically, educationally, and legally. This article (1) summarizes the existing knowledge of ADHD, (2) provides the relevant history and trends, (3) explains the controversy, (4) discusses what is and is not unique about ADHD and stimulant pharmacotherapy, (5) outlines future directions of research, and (6) concludes with a brief analysis of how two North Carolina counties have established community protocols that have improved the screening, treatment, and societal consensus over ADHD and stimulants.

Inattention/overactivity following early severe institutional deprivation: presentation and associations in early adolescence

The current study examined the persistence and phenotypic presentation of inattention/overactivity (I/O) into early adolescence, in a sample of institution reared (IR) children adopted from Romania before the age of 43 months. Total sample comprised 144 IR and 21 non-IR Romanian adoptees, and a comparison group of 52 within-UK adoptees, assessed at ages 6 and 11 years. I/O was rated using Rutter Scales completed by parents and teachers. I/O continued to be strongly associated with institutional deprivation, with continuities between ages 6 and 11 outcomes. There were higher rates of deprivation-related I/O in boys than girls, and I/O was strongly associated with conduct problems, disinhibited attachment and executive function but not IQ more generally, independently of gender. Deprivation-related I/O shares many common features with ADHD, despite its different etiology and putative developmental mechanisms. I/O is a persistent domain of impairment following early institutional deprivation of 6 months or more, suggesting there may be a possible pathway to impairment through some form of neuro-developmental programming during critical periods of early development.

Auditory hallucinations in pre-pubertal children. A one-year follow-up, preliminary findings

BACKGROUND

The aims of this study were to describe the phenomenology of auditory hallucinations in children, to establish links with DSM IV diagnoses and to explore development of the hallucinations over a 12-month period.

METHODS

Outpatients aged 5- to 12-year-old were consecutively recruited. They were interviewed using a questionnaire investigating auditory hallucinations. DSM IV diagnoses were determined. Follow-up assessments were performed at 3, 6, 9 and 12 months.

RESULTS

Ninety children were recruited. Sixteen reported auditory hallucinations. In 53% we observed children's full recovery from hallucinations within 3 months and all of these suffered from anxiety disorders. In 30% hallucinations persisted over 12 months and all showed conduct disorders at this point in time. None was diagnosed as having schizophrenia.

CONCLUSIONS

Our study provides further evidence of the high prevalence of auditory hallucinations in pre-pubertal children presenting to psychiatric clinics. Two different patterns of development were seen. In one group the hallucinations seem unrelated to psychosis although they may be a manifestation of anxiety. In the second, much smaller, persistence of hallucinations appeared linked to conduct disorders.

Etiologic subtypes of attention-deficit/hyperactivity disorder: brain imaging, molecular genetic and environmental factors and the dopamine hypothesis

Multiple theories of Attention-Deficit/Hyper-activity Disorder (ADHD) have been proposed, but one that has stood the test of time is the dopamine deficit theory. We review the narrow literature from recent brain imaging and molecular genetic studies that has improved our understanding of the role of dopamine in manifestation of symptoms of ADHD, performance deficits on neuropsychological tasks, and response to stimulant medication that constitutes the most common treatment of this disorder. First, we consider evidence of the presence of dopamine deficits based on the recent literature that (1) confirms abnormalities in dopamine-modulated frontal-striatal circuits, reflected by size (smaller-than-average components) and function (hypoactivation); (2) clarifies the agonist effects of stimulant medication on dopaminergic mechanisms at the synaptic and circuit level of analysis; and (3) challenges the most-widely accepted ADHD-related neural abnormality in the dopamine system (higher-than-normal dopamine transporter [DAT] density). Second, we discuss possible genetic etiologies of dopamine deficits based on recent molecular genetic literature, including (1) multiple replications that confirm the association of ADHD with candidate genes related to the dopamine receptor D4 (DRD4) and the DAT; (2) replication of differences in performance of neuropsychological tasks as a function of the DRD4 genotype; and (3) multiple genome-wide linkage scans that demonstrate the limitations of this method when applied to complex disorders but implicate additional genes that may contribute to the genetic basis of ADHD. Third, we review possible environmental etiologies of dopamine deficits based on recent studies of (1) toxic substances that may affect the dopamine system in early development and contribute substantially to the etiology of ADHD; (2) fetal adaptations in dopamine systems in response to stress that may alter early development with lasting effects, as proposed by the developmental origins of health and disease hypothesis; and (3) gene-environment interactions that may moderate selective damage or adaptation of dopamine neurons. Based on these reviews, we identify critical issues about etiologic subtypes of ADHD that may involve dopamine, discuss methods that could be used to address these issues, and review old and new theories that may direct research in this area in the future.

Effects of maternal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin on fetal brain growth and motor and behavioral development in offspring rats

The effects of maternal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during pregnancy on fetal brain growth and neurobehavioral development in early developmental stages were investigated using rat offspring. TCDD in corn-oil (0.1microg/kg) was orally administrated to the dams from the 9th to 19th gestational day. When TCDD effects on the fetal brain weight were analyzed on the 19th gestational day, weight ratio of the brain to the whole body, and that of the forebrain without the cerebral cortex to the whole brain were larger in the exposed group than those of the control group, suggesting premature fetal brain development. TCDD effects on motor functions were investigated using newborns in an inclined plane task. Motor development assessed by righting response on an inclination was delayed in the exposed offspring in the 8th-12th postnatal day, especially in male. Also, TCDD effects on active avoidance behavior in a shuttle box were investigated using the offspring after weaning. Latency in the active avoidance learning was longer, and locomotor activity was reduced in the exposed male offspring in the 41st-44th postnatal day. The results demonstrated that maternal TCDD exposure delayed fetal brain growth and neurodevelopment of the offspring in early stage, especially in male rats.

Prediction of adolescent smoking from family and social risk factors at 5 years, and maternal smoking in pregnancy and at 5 and 14 years

AIMS

This study examines associations between maternal smoking and family, social or child risk factors when the child is aged 5 and adolescent smoking. The influence of mothers who smoke in pregnancy or continue to smoke at 14 years was also examined.

DESIGN

The Mater-University of Queensland Study of Pregnancy is a prospective cohort study.

PARTICIPANTS

Participants included 8556 women enrolled between 1981 and 1984 at their first antenatal visit. Completed questionnaires were obtained for 7223 offspring, comprising the study birth cohort. Of the 7223 eligible children a total of 4541 had information on both maternal smoking when the child was aged 5 years and adolescent smoking at 14 years.

MEASUREMENTS

Measures included maternal smoking during pregnancy and when the child was aged 5 and 14 years, child smoking at 14 years, maternal alcohol use, child behaviour problems and social and demographic variables.

FINDINGS

Adolescent smoking was predicted by a risk score at 5 years involving maternal smoking and alcohol use, non-married status, having a partner who had ever been arrested, having four or more children in the household, and child aggression at 5 years. Continued maternal smoking from 5 to 14 years was associated strongly with adolescent smoking. There was also evidence that smoking in late pregnancy may exert an independent effect on adolescent smoking.

CONCLUSIONS

The results suggest the possibility of a direct effect of prenatal smoking on adolescent smoking and highlight a set of environmental risk factors in the development of adolescent smoking. These risk factors may be used as early warning signs that intervention may be needed, and given the similarities with risk factors for other adverse childhood outcomes, the benefits of early intervention may extend beyond smoking to other problem behaviours. The possibility of being able to predict other disorders, because of these associations, also warrants further investigation.