Ginny Russell

The association of attention deficit hyperactivity disorder with socioeconomic disadvantage: alternative explanations and evidence

Background Studies throughout Northern Europe, the United States and Australia have found an association between childhood attention deficit hyperactivity disorder (ADHD) and family socioeconomic disadvantage. We report further evidence for the association and review potential causal pathways that might explain the link. Method Secondary analysis of a UK birth cohort (the Millennium Cohort Study, N = 19,519) was used to model the association of ADHD with socioeconomic disadvantage and assess evidence for several potential explanatory pathways. The case definition of ADHD was a parent-report of whether ADHD had been identified by a medical doctor or health professional when children were 7 years old. Results ADHD was associated with a range of indicators of social and economic disadvantage including poverty, housing tenure, maternal education, income, lone parenthood and younger motherhood. There was no evidence to suggest childhood ADHD was a causal factor of socioeconomic disadvantage: income did not decrease for parents of children with ADHD compared to controls over the 7-year study period. No clinical bias towards labelling ADHD in low SES groups was detected. There was evidence to suggest that parent attachment/family conflict mediated the relationship between ADHD and SES. Conclusion Although genetic and neurological determinants may be the primary predictors of difficulties with activity level and attention, aetiology appears to be influenced by socioeconomic situation.

Social and demographic factors that influence the diagnosis of autistic spectrum disorders

PurposeRecent studies in epidemiology have highlighted the existence of children with autistic difficulties who remain undiagnosed. Other studies have identified ‘access barriers’ to clinics which include factors mediated by parents as well as health and education services. The purpose of this study was to examine whether social and demographic factors play a role in receiving a diagnosis of autistic spectrum disorder (ASD) independently of symptom severity.MethodsRetrospective secondary analysis of a longitudinal UK cohort study, namely, the Avon Longitudinal Study of Parents and Children (ALSPAC).ResultsWith the severity of autistic traits held constant, boys were more likely to receive an ASD diagnosis than girls. Younger mothers and mothers of first-born children were significantly less likely to have children diagnosed with ASD. Maternal depression before and around the time of their children’s autistic difficulties was associated with lack of diagnosis.ConclusionsThe study provides evidence that social as well as biological factors can influence whether children are brought to the clinic.

Dilemmas, diagnosis and de-stigmatization: Parental perspectives on the diagnosis of autism spectrum disorders.

Many children who display autistic behaviours at clinical levels do not receive a formal diagnosis. This study used qualitative methods to examine parental influence in pursuing or avoiding a diagnosis of autism spectrum disorder (ASD). The aim was to explore the function of ASD diagnosis for parents, and examine whether a diagnosis affected how parents perceived ASD. Seventeen parents participated in in-depth semi-structured interviews, which were analyzed using thematic and grounded theory approaches. Data analysis revealed dilemmas faced by parents: whether to act to retain the ‘normal’ status of the child or to ‘normalize’ the child through diagnosis and subsequent remediation. Parents who had received an ASD diagnosis for their children became proactive in trying to reduce stigmatization of ASD more widely, and in some cases actively advocating ASD diagnosis to other parents. Thus their actions may make it more likely that others will opt for diagnosis in the future.

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.

The Strengths and Difficulties Questionnaire as a Predictor of Parent-Reported Diagnosis of Autism Spectrum Disorder and Attention Deficit Hyperactivity Disorder

The Strengths and Difficulties Questionnaire (SDQ) is widely used as an international standardised instrument measuring child behaviour. The primary aim of our study was to examine whether behavioral symptoms measured by SDQ were elevated among children with autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) relative to the rest of the population, and to examine the predictive value of the SDQ for outcome of parent-reported clinical diagnosis of ASD/ADHD. A secondary aim was to examine the extent of overlap in symptoms between children diagnosed with these two disorders, as measured by the SDQ subscales. A cross-sectional secondary analysis of data from the Millennium Birth Cohort (n = 19,519), was conducted. Data were weighted to be representative of the UK population as a whole. ADHD or ASD identified by a medical doctor or health professional were reported by parents in 2008 and this was the case definition of diagnosis; (ADHD n = 173, ASD n = 209, excluding twins and triplets). Study childrens ages ranged from 6.3–8.2 years; (mean 7.2 years). Logistic regression was used to examine the association between the parent-reported clinical diagnosis of ASD/ADHD and teacher and parent-reported SDQ subscales. All SDQ subscales were strongly associated with both ASD and ADHD. There was substantial co-occurrence of behavioral difficulties between children diagnosed with ASD and those diagnosed with ADHD. After adjustment for other subscales, the final model for ADHD, contained hyperactivity/inattention and impact symptoms only and had a sensitivity of 91% and specificity of 90%; (AUC) = 0.94 (95% CI, 0.90–0.97). The final model for ASD was composed of all subscales except the ‘peer problems’ scales, indicating of the complexity of behavioural difficulties that may accompany ASD. A threshold of 0.03 produced model sensitivity and specificity of 79% and 93% respectively; AUC = 0.90 (95% CI, 0.86–0.95). The results support changes to DSM-5 removing exclusivity clauses.

Socioeconomic Associations with ADHD: Findings from a Mediation Analysis

Background Children from disadvantaged socioeconomic backgrounds are at greater risk of a range of negative outcomes throughout their life course than their peers; however the specific mechanisms by which socioeconomic status relates to different health outcomes in childhood are as yet unclear. Aims The current study investigates the relationship between socioeconomic disadvantage in childhood and attention deficit/hyperactivity disorder (ADHD), and investigates putative mediators of this association in a longitudinal population-based birth cohort in the UK. Methods Data from the Avon Longitudinal Study of Parents and Children was used (n = 8,132) to explore the relationship between different measures of socioeconomic status at birth-3 years and their association with a diagnosis of ADHD at age 7. A multiple mediation model was utilised to examine factors occurring between these ages that may mediate the association. Results Financial difficulties, housing tenure, maternal age at birth of child and marital status were significantly associated with an outcome of ADHD, such that families either living in financial difficulty, living in council housing, with younger or single mothers’ were more likely to have a child with a research diagnosis of ADHD at age 7. Financial difficulties was the strongest predictor of ADHD (OR 2.23 95% CI 1.57-3.16). In the multiple mediation model, involvement in parenting at age 6 and presence of adversity at age 2-4 mediated 27.8% of the association. Conclusions Socioeconomic disadvantage, conceptualised as reported difficulty in affording basic necessities (e.g. heating, food) has both direct and indirect impacts on a child’s risk of ADHD. Lower levels of parent involvement mediates this association, as does presence of adversity; with children exposed to adversity and those with less involved parents being at an increased risk of having ADHD. This study highlights the importance of home and environmental factors as small but important contributors toward the aetiology of ADHD.

Identification of children with the same level of impairment as children on the autistic spectrum, and analysis of their service use

BACKGROUND Data from epidemiology have consistently highlighted a disparity between the true prevalence of childhood psychiatric disorders and their recognition as defined by receiving a clinical diagnosis. Few studies have looked specifically at the level of unidentified autistic spectrum disorder (ASD) in the population. METHOD Logistic regression was used to determine the behavioural traits associated with receiving a diagnosis of ASD using data from the Avon Longitudinal Study of Parents and Children (ALSPAC). A composite score was derived to measure levels of autistic traits; undiagnosed children with scores matching those diagnosed with ASD were identified. Levels of educational provision beyond that provided by standard schooling were examined. RESULTS Fifty-five percent of children with autistic traits at the same levels as those who had an autism diagnosis had not been identified as needing extra support from education or specialised health services. Of those who were identified as having special needs, 37.5% had been formally diagnosed with an ASD. For children with impairment at the same level as that associated with Aspergers syndrome, 57% had no special provision at school, and were not accessing specialised health services. Twenty-six percent of those who did have special provision at school had an ASD diagnosis. CONCLUSIONS The results suggest that there may be a substantial proportion of children on the autistic spectrum who are never identified by services.

A qualitative analysis of lay beliefs about the aetiology and prevalence of autistic spectrum disorders.

INTRODUCTION There has been a dramatic increase in the prevalence of autistic spectrum disorders (ASD) in the last 20 years. The reasons for this are disputed. The consensus among epidemiologists and other experts is that greater case load is due to changes in diagnostic practice rather than reflecting changing aetiological factors leading to a true increase in incidence. We set out to examine lay views concerning the aetiology and prevalence of ASD and whether they conflict with or support this consensus position. METHODS Over 100 unsolicited communications (letters e-mail and several telephone calls) were received by a UK epidemiological study of ASD. We carried out a qualitative analysis of all correspondence in order to examine spontaneously expressed lay beliefs about the prevalence and aetiology of ASD. RESULTS The majority of correspondents suggested theories about environmental causes of ASD. This study demonstrates the strength of lay belief that the true incidence of autism is rising, and this is due to risks from modern technologies and changing lifestyles. CONCLUSION This study based on unsolicited data highlights the contrast between lay explanations of increasing prevalence and the consensus opinion of medical experts. It also demonstrates how many people in direct contact with ASD have important information to share.

Social and Behavioural Outcomes in Children Diagnosed with Autism Spectrum Disorders: A Longitudinal Cohort Study.

OBJECTIVE   To compare social and behavioural outcomes between children formally diagnosed with autism spectrum disorders (ASD) with those of children who displayed autistic traits at preschool age, but remained undiagnosed as teenagers. METHOD   A secondary analysis of data from a birth cohort study, the Avon Longitudinal Study of Parents and Children (N = 13,944), in SW England. Children clinically diagnosed with ASD were identified from their medical records (n = 71). A comparison group, who displayed autistic traits at age 3-4, but without ASD diagnosis were also identified (n = 142). Social and behavioural outcomes in adolescence were compared between the two groups. RESULTS   Children with ASD diagnoses were more impaired as teenagers that those in the comparison group on a range of measures of autistic-like behaviour. The developmental trajectory of prosocial behaviour showed that differences between the case and comparison groups increased dramatically in the preschool and early primary years, but that after 6 years the trajectories were similar. CONCLUSIONS   The divergence of the clinically diagnosed group and the nondiagnosed group in measures of autistic-like behaviour increased with age. This study provides evidence that it may be difficult to distinguish preschool age children who exhibit autistic-like symptoms but improve, from those who go on to develop lifelong impairment.

Changes in diagnosis rates and behavioural traits of autism spectrum disorder over time

Background The increased proportion of UK children diagnosed with autism spectrum disorder (ASD) has been attributed to improved identification, rather than true increase in incidence. Aim To explore whether the proportion of children with diagnosis of ASD and/or the proportion with associated behavioural traits had increased over a 10-year period. Method A cross-cohort comparison using regression to compare prevalence of diagnosis and behavioural traits over time. Participants were children aged 7 years assessed in 1998/1999 (n=8139) and 2007/2008 (n=13 831). Results During 1998/1999, 1.09% (95% CI 0.86–1.37) of children were reported as having ASD diagnosis compared with 1.68% (95% CI 1.42–2.00) in 2007/2008: risk ratio (RR)=1.55 (95% CI 1.17–2.06), P=0.003. The proportion of children in the population with behavioural traits associated with ASD was also larger in the later cohort: RR=1.61 (95% CI 1.35–1.92), P<0.001. Increased odds of diagnosis at the later time point was partially accounted for by adjusting for the increased proportion of children with ASD-type traits. Conclusions Increased ASD diagnosis may partially reflect increase in rates of behaviour associated with ASD and/or greater parent/teacher recognition of associated behaviours. Declaration of interest None. Copyright and usage