Number Of Attention-deficit/hyperactivity Disorder Symptoms Research Articles

Occupational pesticide exposure and symptoms of attention deficit hyperactivity disorder in adolescent pesticide applicators in Egypt

BackgroundExposure to environmental chemicals, including organophosphorus pesticides, is associated with behavioral disorders such as attention deficit hyperactivity disorder (ADHD). However, the impact of occupational pesticide exposure on ADHD development in adolescents has not been examined. ObjectiveWe examined the association between exposure to chlorpyrifos and ADHD symptoms among adolescents in Egypt. MethodsAdolescent pesticide applicators and non-applicators, 12–21 years old, participated in a 10-month longitudinal study examining health effects from pesticide exposure. Repeated urine and blood samples were collected at various time points during the 10-months to assess biomarkers of chlorpyrifos exposure (urinary trichloro-2-pyridinol or TCPy) and effect (blood acetyl cholinesterase activity and butyryl cholinesterase activity). Parents from a subset of the cohort (N = 64) completed the Short Form of Conners’ Parent Rating Scale – Revised. Poisson regressions were used to examine the associations between the number of ADHD symptoms and occupation and biomarkers. ResultsPesticide applicators had significantly more symptoms of ADHD than participants in the non-applicator group. Urinary TCPy levels were associated with increased symptoms, demonstrating a dose-response effect. Applicators with ADHD reported applying pesticides for more hours during the application season and had greater cumulative TCPy levels than participants without ADHD. One fourth of all applicators met the criteria for an ADHD diagnosis (having 6 or more reported symptoms). ConclusionsThis study provides preliminary evidence of an association between occupational exposure to chlorpyrifos and ADHD symptoms among adolescent pesticide applicators in spite of its limited small sample size. There is a critical need to investigate the susceptibility of children and adolescents to repeated occupational and environmental exposures to pesticides because the developing brain may be uniquely sensitive to the neurotoxic effects of these agents.

Diagnostic operationalization and phenomenological heterogeneity in psychiatry: the case of attention deficit hyperactivity disorder

Introduction. We assessed the impact of polythetic conceptualizations of mental disorders on the validity and reliability of psychiatric diagnosis, with a specific focus on two levels of heterogeneity: phenomenological and pathophysiological. Objective. We investigated this issue using attention deficit hyperactivity disorder (ADHD) as an example. Method. We examined individuals from two samples enriched for psychopathology (n = 1 255 children in Porto Alegre and 1 257 children in São Paulo, Brazil). We conducted a series of data analyses to investigate phenomenological heterogeneity, including confirmatory factor analysis. We also investigated pathophysiological heterogeneity using symptom-level regressions between ADHD symptoms and four neurocognitive processes consistently linked to ADHD (working memory, inhibitory control, intra-subject variability in reaction times, and temporal processing). Lastly, we assessed the performance of polythetic systems for reliability testing inter-rater and test-rest reliability of two well-known symptomatic scales. Results. Among the 116 200 possible combinations of symptoms to achieve DSM symptomatic threshold for categorical ADHD diagnosis, we found 173 combinations in the two independent samples, and only four were replicated in both samples (2.3%). We also found that the number of ADHD symptoms is a poor indicator of variation in the general ADHD latent trait. Overall, symptoms did not have specific profiles of associations with any of the neurocognitive processes. Reliability analyses revealed that increasing the number of items augments overall reliability of measurements. Discussion and conclusion. Our findings illustrate both potential benefits and problems inherent to the polythetic system for ADHD. Implications for the search of mechanisms underlying psychiatric disorders are discussed.

Combined effects of prenatal exposure to polycyclic aromatic hydrocarbons and material hardship on child ADHD behavior problems

ImportancePolycyclic aromatic hydrocarbons (PAH) are carcinogenic and neurotoxic combustion by-products commonly found in urban air. Exposure to PAH is disproportionately high in low income communities of color who also experience chronic economic stress. ObjectiveIn a prospective cohort study in New York City (NYC) we previously found a significant association between prenatal PAH exposure and Attention Deficit Hyperactivity Disorder (ADHD) behavior problems at age 9. Here, we have evaluated the joint effects of prenatal exposure to PAH and prenatal/childhood material hardship on ADHD behavior problems. Materials and MethodsWe enrolled nonsmoking African-American and Dominican pregnant women in New York City between 1998 and 2006 and followed their children through 9 years of age. As a biomarker of prenatal PAH exposure, PAH-DNA adducts were measured in maternal blood at delivery and were dichotomized at the limit of detection (to indicate high vs. low exposure). Maternal material hardship (lack of adequate food, housing, utilities, and clothing) was self-reported prenatally and at multiple time points through child age 9. Latent variable analysis identified four distinct patterns of hardship. ADHD behavior problems were assessed using the Conners Parent Rating Scale- Revised. Analyses adjusted for relevant covariates. ResultsAmong 351 children in our sample, across all hardship groups, children with high prenatal PAH exposure (high adducts) generally had more symptoms of ADHD (higher scores) compared to those with low PAH exposure. The greatest difference was seen among the children with hardship persisting from pregnancy through childhood. Although the interactions between high PAH exposure and hardship experienced at either period (“persistent” hardship or “any” hardship) were not significant, we observed significant differences in the number of ADHD symptoms between children with high prenatal PAH exposure and either persistent hardship or any hardship compared to the others. These differences were most significant for combined high PAH and persistent hardship: ADHD Index (p < 0.008), DSM-IV Inattentive (p = 0.006), DSM-IV Hyperactive Impulsive problems (p = 0.033), and DSM-IV Index Total (p = 0.009). ConclusionThe present findings add to existing evidence that co-exposure to socioeconomic disadvantage and air pollution in early life significantly increases the risk of adverse neurodevelopmental outcomes. They suggest the need for multifaceted interventions to protect pregnant mothers and their children.

The therapeutic potential of working memory training for treating mental disorders.

The therapeutic potential of working memory training for treating mental disorders.

Hot and Cool Executive Functions in Children with Attention-Deficit/Hyperactivity Disorder and Comorbid Oppositional Defiant Disorder.

While neuropsychological deficits in both "hot" and "cool" executive functions (EFs) have been documented among individuals with attention-deficit/hyperactivity disorder (ADHD), these EF deficits are not universal across all individuals with this diagnosis. One potential moderator of executive dysfunction may be the presence of comorbid oppositional defiant disorder (ODD). This study examined the association between "hot" and "cool" EFs and comorbid ODD in children with ADHD. Thirty-three children with ADHD and comorbid ODD (ADHD+ODD), 67 with ADHD without ODD (ADHD-ODD), and 30 typically developing controls participated. Children were 7-12 years of age. "Cool" EFs were assessed with a spatial span task and a card sorting test. "Hot" EFs were assessed using a delay discounting task and a gambling task. ADHD-ODD and ADHD+ODD groups performed more poorly on "cool" EF tasks than controls, but did not differ from each other. Furthermore, the number of ADHD symptoms, but not ODD symptoms, was associated with "cool" EF scores. The three groups did not differ on "hot" EF tasks and the number of ADHD or ODD symptoms was unrelated to "hot" EF scores. In sum, children with ADHD presented with "cool" EF deficits which appear to be unrelated to ODD comorbidity. However, "hot" EF deficits were not present among children with ADHD, irrespective of comorbid ODD status.

The role of adverse life events on depression in older adults with ADHD

BackgroundComorbidity between Attention-Deficit/Hyperactivity Disorder (ADHD) and depression is high, also in older adults. Thus far it is not well understood why ADHD and depression are so strongly interrelated. One factor that may play a role in older adults with ADHD is an increased risk of experiencing adverse life events. MethodsSix year follow-up data were used from the Longitudinal Aging Study Amsterdam (LASA). To diagnose ADHD, the DIVA 2.0, a diagnostic interview was administered among a subsample (N=230, age 60–94). In addition to the ADHD diagnosis, the associations between the number of ADHD symptoms, depressive symptoms and adverse life events were examined. Data were analyzed by means of logistic and linear regression analyses. ResultsCompared to older adults without ADHD, those with ADHD reported more serious conflicts. The risk of depression in older adults with ADHD was partly explained by serious conflicts. Furthermore, the association between ADHD severity and depression was stronger in those who experienced serious conflicts and those who experienced more adverse life events. LimitationsThe ADHD diagnosis was based on the DSM-IV criteria, which were developed for children, and have not yet been validated in (older) adults. ConclusionsHaving conflicts with others and accumulation of adverse life events over time partly explained the association between ADHD and depression. Better and earlier treatment of ADHD may prevent the development of depression in the presence of life events associated with ADHD.

Negative parenting behavior and childhood oppositional defiant disorder: Differential moderation by positive and negative peer regard

Although negative parenting behavior and peer status are independently associated with childhood conduct problems (e.g., oppositional defiant disorder (ODD)), relatively little is known about their interplay, particularly in relation to differentiated measures of positive and negative peer regard. To improve the specificity of the association of negative parenting behavior and peer factors with ODD, we explored the potential interaction of parenting and peer status in a sample of 169 five-to ten-year-old ethnically diverse children with and without attention-deficit/hyperactivity disorder (ADHD) assessed using multiple measures (i.e., rating scales, interview) and informants (i.e., parents, teachers). Controlling for children's age, sex, number of ADHD symptoms, and parents' race-ethnicity, peer acceptance inversely predicted and inconsistent discipline, harsh punishment, and peer rejection were each positively associated with ODD symptom severity. Interactive influences were also evident such that inconsistent discipline and harsh punishment each predicted elevated ODD but only among children experiencing low peer acceptance or high peer rejection. These findings suggest that supportive environments, including peer acceptance, may protect children from negative outcomes associated with inconsistent discipline and harsh punishment. Findings are integrated with theories of social support, and we additionally consider implications for intervention and prevention.

Neurophysiological differences in inhibitory control between adults with ADHD and their peers

Inhibitory control allows individuals to suppress prepotent responses and resist irrelevant stimuli, and is thought to be a core deficit in Attention-deficit/hyperactivity disorder (ADHD). Whereas numerous studies have investigated neural mechanisms underlying inhibitory control deficits in children with ADHD, less is known about underlying mechanisms in young adults with ADHD. This study explores the neural correlates of inhibitory control in college students with ADHD—a population that, despite comparatively high educational attainment, still shows marked functional impairments in academic, social, and occupational functioning. Participants were 54 college students with ADHD and 29 typically developing peers. Specifically the fronto-centrally located N2 and the centro-parietal P3 event-related potential (ERP) components were hypothesized to show decreased amplitudes for the ADHD group due to their known association with inhibitory control. Dense array electroencephalography (EEG) data was collected during a Go/nogo task. Results show lower accuracy rates for the ADHD group and significant reductions in P3 amplitude as well as a trend for reduced N2 amplitude in nogo trials where subjects successfully inhibited a response. Notably, nogo N2 and P3 amplitudes correlated with the number of ADHD symptoms: namely, smaller amplitudes were associated with more symptoms. We conclude that when compared to their typically developing peers, relatively high functioning adults with ADHD still show a deviant neural signature. These results contribute to the growing literature of adult ADHD and increase our understanding of the neural correlates of inhibitory control associated with ADHD.

Attention‐Deficit/Hyperactivity Disorder, Physical Health, and Lifestyle in Older Adults

To increase insight into the effect of attention-deficit/hyperactivity disorder (ADHD) on health in general in older adults. Two-phase sampling side-study. Longitudinal Aging Study Amsterdam (LASA). Two hundred twenty-three randomly selected LASA respondents. Information was collected during home visits on physical health, medication use, and lifestyle characteristics in Phase 1 and on ADHD diagnosis in Phase 2. The associations between independent variables and ADHD were examined with linear and logistic regression analyses. The adjusted regression estimates of the linear regression analysis showed that the number of ADHD symptoms was positively associated with the presence of chronic nonspecific lung diseases (CNSLD) (B = 2.58, P = .02), cardiovascular diseases (B = 2.18, P = .02), and number of chronic diseases (B = 0.69, P = .04) and negatively associated with self-perceived health (B = -2.83, P = .002). Lifestyle is not a mediator of the association between ADHD and physical health. Attention-deficit/hyperactivity disorder in older adults was associated with chronic physical illness and poorer self-perceived health. Contrary to expectations, there were no associations between symptoms of ADHD and lifestyle variables.

Exploration of ADHD Subtype Definitions and Co-Occurring Psychopathology in a Missouri Population-Based Large Sibship Sample

There is some debate regarding the utility of Attention-Deficit/ Hyperactivity Disorder (ADHD) subtypes as currently defined. Differences in co-occurring psychopathology among subtypes would support the validity of subtype definitions. To explore how ADHD subtype relates to co-occurring psychopathology in a large population-based sample of children and adolescents (n=5744). Parents completed the Strengths and Weaknesses of ADHD-symptoms and Normal behavior (SWAN) questionnaire, the Child Behavior Checklist (CBCL) and the Social Responsiveness Scale (SRS). Methods including discriminant analysis, principal components analysis, and fractional polynomial regression were used to examine the relationship between ADHD diagnostic subtypes and co-occurring psychopathology. Children with different ADHD subtypes show differences on several CBCL subscales. A combination of CBCL subscales and SRS score had good ability to discriminate ADHD subtypes. Conversely, for the same overall number of ADHD symptoms, individuals who present with both inattentive and hyperactive/impulsive symptoms exhibit higher severity of co-occurring psychopathology on a summary measure derived from principal components analysis of the CBCL subscales and SRS. This includes some subjects who fail to meet the DSM-IV-TR ADHD symptom criterion due to having less than 6 inattentive and less than six hyperactive-impulsive symptoms, yet have ADHD symptom severity similar to those with the inattentive or hyperactive-impulsive subtype. Several convergent lines of analysis provide support for the continued use of ADHD subtypes (or current presentation symptom profiles), as evidenced by differences in co-existing psychopathlogy. We also found that current diagnostic criteria may fail to identify a potentially impaired group of individuals who have low-to-moderate levels of both inattention and hyperactivity/impulsivity. Under the upcoming DSM-5, it will be important for clinicians to consider the option of giving an ADHD "not elsewhere classified" diagnosis to such children.

A Controlled Trial of Working Memory Training for Children and Adolescents with ADHD

This study assessed the efficacy of a 5-week, intensive working memory training program for 52 children and adolescents (ages 7–17) who had Attention-Deficit/Hyperactivity Disorder (ADHD) and other comorbid diagnoses. This study provided a treatment replication since the waitlist control group also completed training and was included in the follow-up data analyses. Parents and teachers completed paper-and-pencil measures of working memory, executive functioning, and ADHD symptoms at baseline, posttreatment, and 4-month follow-up. Parent ratings indicated that participants improved on inattention, overall number of ADHD symptoms, initiation, planning/organization, and working memory. Teacher ratings approached significance at posttreatment and at 4-month follow-up on and Initiate scale. Working memory training appears promising as an intervention in improving executive functioning and ADHD symptoms.

Relationship between cigarette smoking and childhood symptoms of inattention and hyperactivity/impulsivity in alcohol-dependent adults without attention-deficit hyperactivity disorder

Symptoms of inattention and hyperactivity/impulsivity that fall below the DSM-IV diagnostic threshold for attention-deficit hyperactivity disorder (ADHD) may be associated with the high prevalence of smoking among individuals with alcohol dependence, yet no studies to date have examined the relationship between subthreshold ADHD symptoms and cigarette smoking in this group. We hypothesized that increasing levels of ADHD symptoms would be associated with increasing risk of lifetime smoking and nicotine dependence, concentration problems secondary to nicotine withdrawal, and maintenance of smoking. Participants were alcohol-dependent adults (n = 242) who did not meet criteria for ADHD or a current Axis I disorder other than alcohol and nicotine dependence. All participants were involved in treatment for alcohol dependence but not smoking cessation. The Semi-Structured Assessment for the Genetics of Alcoholism was administered to collect demographic and smoking history data and to assess symptoms of ADHD and other psychiatric disorders. A higher number of self-reported ADHD symptoms were associated with increased likelihood of ever smoking (p = .026), nicotine dependence (p = .017), and impaired concentration as a symptom of nicotine withdrawal (p = .046). There was no relationship between the number of ADHD symptoms and classification as a former versus current smoker (p = .333). Childhood symptoms of inattention and hyperactivity/impulsivity are related to cigarette smoking and nicotine dependence among alcohol-dependent individuals at levels below the ADHD diagnostic threshold. Conceptualization of ADHD symptoms as occurring on a continuum may aid identification of and early intervention for individuals who are at highest risk for initiating smoking and developing nicotine dependence.

Gender Comparisons of Service Use Among Youth With Attention-Deficit/Hyperactivity Disorder

The authors compared service-use patterns and factors associated with service use for 279 boys and 119 girls who met the criteria for attention-deficit/hyperactivity disorder (ADHD), as defined in the Diagnostic and Statistical Manual of Mental Disorders—Fourth Edition ( DSM-IV).The participants had been identified from a nationally representative sample of Australian youth. Boys and girls with ADHD did not differ in their rates of service use, the types of services they attended (school/education or health-based services), the types of help they received, and the main problems for which they received help, with the exception that boys had higher rates of medication use. However, the factors associated with service use were not uniform across gender. For boys, problems with schoolwork or grades and number of ADHD symptoms were the main predictors of service use,whereas for girls the main predictor was the presence of depressive disorders.These findings suggest there are gender differences in the factors associated with service use among children with ADHD that are likely to have implications for assessment and treatment of the disorder.

Association of the dopamine D4 receptor gene 7-repeat allele with neuropsychological test performance of children with ADHD.

Association between attention deficit hyperactivity disorder (ADHD) and the 7-repeat allele of a variant (a 48 bp variable number of tandem repeats) in the dopamine D4 receptor gene (DRD4) has been widely documented. A meta-analysis of 21 studies revealed evidence of significant association. In this article the authors examine whether the DRD4 7-repeat allele is associated with performance on a variety of neuropsychological tasks in children with ADHD. The presence or absence of the 7-repeat allele was determined in 133 drug-naive children 6 to 13 years of age who fulfilled diagnostic criteria for ADHD. These children were then assessed on several neuropsychological tests known to be associated with attention, impulse control, and response inhibition (the Continuous Performance Test, Matching Familiar Figures Test, Go/No Go Task, and Stop Task). Activity levels were assessed with an actigraph. Children with and without at least one 7-repeat allele were compared with each other and with children in a previous population-based study. Children who had the 7-repeat allele had significantly more incorrect responses on the Matching Familiar Figures Test (16.1 versus 14.3) than children who did not have the allele. Children with the allele also had shorter mean reaction times for incorrect responses on the Matching Familiar Figures Test (846.1 versus 1103.7 msec) and on the Stop Task (116.6 versus 134.1 msec) than children without the allele. Children with the allele also displayed higher activity levels. The children with and without the allele did not differ significantly in number of ADHD symptoms when the symptoms were split into the areas of inattention and hyperactivity/impulsivity. Both groups of children with ADHD were more neuropsychologically impaired than the nonpatient comparison group. In children with ADHD, possession of the DRD4 7-repeat allele appears to be associated with an inaccurate, impulsive response style on neuropsychological tasks that is not explained by ADHD symptom severity.

One-year outcome of adolescent females referred for conduct disorder and substance abuse/dependence

We investigated whether substance abuse/dependence, conduct disorder, and other psychiatric disorders improved in adolescent females who were referred to outpatient treatment and which variables were related to 1-year outcome. Forty-six out of 60 conduct-disordered (CD) adolescent females with substance abuse or dependence were re-evaluated approximately 1 year after discharge. Treatment length averaged 16 weeks. Significant improvements were seen in three areas: (1) criminality and CD; (2) attention deficit hyperactivity disorder (ADHD); and (3) educational and vocational status. However, neither substance involvement nor depression improved, regardless of length of stay in treatment, and these females demonstrated significant risky sexual behaviors. In contrast to our previous work with adolescent males (Crowley, T.J., Mikulich, S.K., Macdonald, M., Young, S.E., Zerbe, G.O., 1998. Substance-dependent, conduct-disordered adolescent males: severity of diagnosis predicts 2-year outcome. Drug Alcohol Depend. 49, 225–237), we were not able to identify pre-intake variables, other than performance IQ, that were related to substance use and conduct outcomes. Only two post-treatment factors (peer problems and number of ADHD symptoms at follow-up) were found to be related to CD and substance use disorders outcomes. The overall lack of pre- and post-treatment predictors presents interesting challenges for future research on adolescent females with these disorders.

Cognitive and Familial Contributions to Conduct Disorder in Children

Although young children with conduct disorder (CD) are suspected of having verbal and executive function deficits, most studies that investigated this hypothesis did not control for attention deficit hyperactivity disorder (ADHD). Furthermore, relatively little is known about the interaction between cognitive deficits and familial factors in explaining the onset and persistence of CD in children. The participants in this study were 57 children with CD and 35 controls aged 7 to 12 years. At 1-year follow-up, 41 of the participants with CD were reassessed. Children with CD were found to be significantly impaired in four of five executive function measures after ADHD symptoms and socioeconomic status (SES) were controlled. Executive function test performance, number of ADHD symptoms, and familial characteristics (SES, parental punishment) together correctly classified 90% of the participants. Only the number of ADHD symptoms was found to significantly improve prediction of CD 1 year later beyond that afforded by number of CD symptoms a year earlier. Findings indicate that children with CD and ADHD symptoms are especially at risk for persistent antisocial behaviour. Results also highlight the importance of treatment programs that cover both cognitive and familial aspects associated with CD.