Symptom profiles in children with ADHD: effects of comorbidity and gender

OBJECTIVE: To examine ratings and objective measures of attention-deficit/hyperactivity disorder (ADHD) symptoms to assess whether ADHD children with and without comorbid conditions have equally high levels of core symptoms and whether symptom profiles differ as a function of comorbidity and gender. METHOD: Four hundred ninety-eight children from the NIMH Collaborative Multisite Multimodal Treatment Study of Children With Attention-Deficit/Hyperactivity Disorder (MTA) were divided into comorbid groups based on the parent Diagnostic Interview Schedule for Children and assessed via parents' and teachers' Swanson, Nolan, and Pelham (SNAP) ratings and a continuous performance test (CPT). Comorbidity and gender effects were examined using analyses of covariance controlled for age and site. RESULTS: CPT inattention, impulsivity, and dyscontrol errors were high in all ADHD groups. Children with ADHD + oppositional defiant or conduct disorder were rated as more impulsive than inattentive, while children with ADHD + anxiety disorders (ANX) were relatively more inattentive than impulsive. Girls were less impaired than boys on most ratings and several CPT indices, particularly impulsivity, and girls with ADHD + ANX made fewer CPT impulsivity errors than girls with ADHD-only. CONCLUSIONS: Children with ADHD have high levels of core symptoms as measured by rating scales and CPT, irrespective of comorbidity. However, there are important differences in symptomatology as a function of comorbidity and gender.     

Validity of DSM-IVADHD subtypes in a nationally representative sample of Australian children and adolescents.

OBJECTIVE: To examine the discriminant validity of DSM-IV attention-deficit/hyperactivity disorder (ADHD) subtypes in a nationally representative sample of Australian youths. METHOD: The Diagnostic Interview Schedule for Children, including the symptom-specific impairment questions, was administered to 3,597 parents of children aged 6 to 17 years (response rate = 70%). Parents also completed questionnaires assessing children's emotional and behavioral problems and quality of life. RESULTS: Current DSM-IVADHD prevalence was 7.5% (6.8% with impairment) with inattentive types being more common than hyperactive-impulsive and combined types. ADHD was more prevalent among young males and was linked to social adversity, particularly for combined types. Compared with non-ADHD controls, all three ADHD subtypes were rated as having more emotional and behavioral problems and lower psychosocial quality of life, with combined types consistently rated the most impaired. Combined types received higher ratings than hyperactive-impulsive and inattentive types on externalizing behavior problems, disruption to family activities, and symptom-specific impairments with schoolwork and peer-related activities. Inattentive types were rated as having lower self-esteem, more social and school-related problems, but fewer externalizing problems than hyperactive-impulsive types. CONCLUSION: These findings support the view of DSM-IVADHD subtypes as distinct clinical entities with impairments in multiple domains.     

Influence of gender on attention deficit hyperactivity disorder in children referred to a psychiatric clinic.

OBJECTIVE: The substantial discrepancy in the male-to-female ratio between clinic-referred (10 to 1) and community (3 to 1) samples of children with attention deficit hyperactivity disorder (ADHD) suggests that gender differences may be operant in the phenotypic expression of ADHD. In this study the authors systematically examined the impact of gender on the clinical features of ADHD in a group of children referred to a clinic. METHOD: The study included 140 boys and 140 girls with ADHD and 120 boys and 122 girls without ADHD as comparison subjects. All subjects were systematically assessed with structured diagnostic interviews and neuropsychological batteries for subtypes of ADHD as well as emotional, school, intellectual, interpersonal, and family functioning. RESULTS: Girls with ADHD were more likely than boys to have the predominantly inattentive type of ADHD, less likely to have a learning disability, and less likely to manifest problems in school or in their spare time. In addition, girls with ADHD were at less risk for comorbid major depression, conduct disorder, and oppositional defiant disorder than boys with ADHD. A statistically significant gender-by-ADHD interaction was identified for comorbid substance use disorders as well. CONCLUSIONS: The lower likelihood for girls to manifest psychiatric, cognitive, and functional impairment than boys could result in gender-based referral bias unfavorable to girls with ADHD.     

Mothers’ and Fathers’ Attributions and Beliefs in Families of Girls and Boys with Attention-Deficit/Hyperactivity Disorder

This study examined parent and child gender effects on parents’ attributions and beliefs in regards to child symptoms of attention-deficit/hyperactivity disorder (ADHD). Participants included mothers and fathers of 19 girls and 17 boys with ADHD. Groups of boys and girls, aged 5–13 years, were equated on age and medication status, as well as ADHD symptom severity. These groups also were similar in the severity of comorbid oppositional behaviors and internalizing problems, as well as a variety of demographic characteristics. Parents’ attributions for child behavior were assessed in response to written scenarios describing either hyperactive/impulsive or inattentive symptoms of ADHD. Parents also completed a questionnaire assessing beliefs and knowledge about ADHD. There were no child gender effects for parents’ attributions or beliefs. All parents attributed inattentive symptoms to more internal, global and stable causes than impulsive symptoms. Mothers attributed both inattentive and impulsive child symptoms to more global and stable causes than did fathers. Fathers, but not mothers, reported more negative reactions to ADHD symptoms that were perceived as having an internal cause. Finally, mothers scored higher on beliefs in behavior management than did fathers, and fathers believed more in psychological causes and treatments for ADHD. Possible explanations for and implications of these results are explored.     

Parent-teacher concordance for DSM-IV attention-deficit/hyperactivity disorder in a clinic-referred sample

OBJECTIVE: To examine concordance between parent and teacher reports of DSM-IV attention-deficit/hyperactivity disorder (ADHD) and its symptoms. METHOD: Parents and teachers of 74 clinically referred children were interviewed using the ADHD module of the Diagnostic Interview Schedule for Children. Parent-teacher agreement for the diagnosis of ADHD and its subtypes, as defined in DSM-IV, as well as parent-teacher concordance of in-school ADHD symptoms, was examined. RESULTS: Agreement between parents and teachers was found to be relatively poor, with virtually no agreement for individual ADHD subtypes. Diagnoses based on either parent or teacher report frequently yielded a diagnosis of either inattentive or hyperactive-impulsive subtype of ADHD. However, when cross-informant data were used to form diagnoses, these subtypes became relatively rare, with most cases meeting criteria for ADHD combined type. In addition, parent reports of in-school behavior were more highly correlated with their own reports of their child's behavior at home than with teacher reports of their child's behavior in school. CONCLUSIONS: These data suggest that the diagnosis of ADHD inattentive or hyperactive-impulsive subtype based on data from a single informant may be of questionable validity, and they point to the importance of using multiple informants when diagnosing this disorder in clinically referred samples.     

Comparison of attention-deficit/hyperactivity disorder symptom subtypes in Ukrainian schoolchildren

OBJECTIVE: This study used a parent-completed, DSM-IV-referenced rating scale to examine prevalence rates of attention-deficit/hyperactivity disorder (ADHD) behaviors and differences between subtypes in 10- to 12-year-old Ukrainian children. METHOD: During 1997, a total of 600 parents and children residing in Kyiv, Ukraine, and their teachers participated in extensive clinical assessments using standard Western measures. RESULTS: The screening prevalence rate of ADHD behaviors was 19.8%: 7.2% for inattentive (I), 8.5% for hyperactive-impulsive (HI), and 4.2% for combined (C). Post hoc comparisons indicated a number of significant (p < .05) group differences. Mothers of children with ADHD symptoms reported higher rates of disruptive behavior, negative mother-child interactions, and physical punishment than the non-ADHD group. Teachers rated children with ADHD as more hyperactive and inattentive, but only the HI subtype was rated more oppositional than non-ADHD students. The I subtype was less academically proficient and socially adept (but less likely to have behavior problems). The C subtype was the most behaviorally disruptive (mother ratings), and their fathers were more likely to be aggressive and abuse alcohol. The HI subtype also had problems with disruptive behavior but were less socially impaired. CONCLUSIONS: Although symptom prevalence rates are higher in Ukraine than the United States, this study provides additional evidence supporting DSM-IV ADHD subtypes as distinct clinical entities.     

Motor coordination problems in children and adolescents with ADHD rated by parents and teachers: effects of age and gender

Summary. Objective. ADHD is frequently accompanied by motor coordination problems. However, the co-occurrence of poor motor performance has received less attention in research than other coexisting problems in ADHD. The underlying mechanisms of this association remain unclear. Therefore, we investigated the prevalence of motor coordination problems in a large sample of children with ADHD, and the relationship between motor coordination problems and inattentive and hyperactive/impulsive symptoms. Furthermore, we assessed whether the association between ADHD and motor coordination problems was comparable across ages and was similar for both genders. Method. We investigated 486 children with ADHD and 269 normal controls. Motor coordination problems were rated by parents (Developmental Coordination Disorder Questionnaire) and teachers (Groningen Motor Observation Scale). Results. Parents and teachers reported motor coordination problems in about one third of children with ADHD. Problems of fine and gross motor skills, coordination skills and motor control were all related to inattentive rather than hyperactive/impulsive symptoms. Relative to controls, motor coordination problems in ADHD were still present in teenagers according to parents; the prevalence diminished somewhat according to teachers. Boys and girls with ADHD were comparably affected, but motor performance in controls was better in girls than in boys. Conclusions. Motor coordination problems were reported in one third of children with ADHD and affected both boys and girls. These problems were also apparent in adolescents with ADHD. Clinicians treating children with ADHD should pay attention to co-occurring motor coordination problems because of the high prevalence and the negative impact of motor coordination problems on daily life. The first two authors contributed equally. Correspondence: Barbara Franke, Department of Human Genetics, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands     

Disruptive behavior in children with Tourette's syndrome: association with ADHD comorbidity,tic severity,and functional impairment

OBJECTIVE: To examine the association of disruptive behavior with social, adaptive, and family functioning in Tourette's syndrome (TS) with and without comorbid attention-deficit/hyperactivity disorder (ADHD). METHOD: The sample included 207 children (144 boys and 63 girls) between the ages of 7 and 18 years. Forty-two children received a diagnosis of TS-only, 52 received a diagnosis of ADHD-only, 52 children had TS+ADHD, and there were 61 unaffected control children. Best-estimate DSM-IV diagnoses were assigned on the basis of structured interviews and clinical ratings. Dependent measures included parent and teacher ratings of disruptive behavior, parent ratings of social and family functioning, and the Vineland Adaptive Behavior Scales. RESULTS: Children with TS-only did not differ from unaffected controls on the parent ratings of aggression and delinquent behavior or on the teacher ratings of conduct problems. By contrast, children with TS+ADHD were rated significantly above unaffected controls and similar to children with ADHD-only on these indices of disruptive behavior. Hierarchical regression analyses revealed that aggression and delinquency scores added unique contributions to impairment in social and family functioning, controlling for age, gender, and diagnostic status. CONCLUSIONS: Comorbid ADHD is highly associated with disruptive behavior and functional impairment in children with TS. When disruptive behavior problems are present, there is an additional burden on children's social and family functioning.     

Executive function in adolescents with ADHD

OBJECTIVE: The aim of this study was to clarify executive function weakness in attention-deficit/hyperactivity disorder (ADHD) during adolescence and determine the specificity of executive function weakness to ADHD symptom domains. METHOD: A total of 182 adolescents (105 boys), ages 13 to 17 years, completed a multistage diagnostic assessment; 85 were diagnosed with ADHD: 43 primarily Inattentive type (ADHD-PI) and 42 Combined type (ADHD-C). Participants completed the Stop, Trail Making, Wisconsin Card Sort, and Stroop tasks. RESULTS: The ADHD group exhibited impaired performance compared with the non-ADHD group on executive function measures (multivariate p < .05); there were no ADHD subtype differences. A composite executive function factor was significantly related to inattentive but not hyperactive-impulsive symptoms. CONCLUSIONS: Executive function weakness in adolescent ADHD is specifically related to symptoms of inattention-disorganization. Results are congruent with a dual-pathway model of ADHD cognitive mechanisms.     

Increased frequency of rolandic spikes in ADHD children

PURPOSE: Some children with rolandic epilepsy have associated neuropsychiatric deficits resembling symptoms of attention deficit-hyperactivity disorder (ADHD), the most common neurobehavioral disorder of childhood. The clinical overlap between both syndromes has received relatively little attention. The study examines the frequency of rolandic spikes in nonepileptic children with ADHD and compares it with a historic control group of 3,726 normal school-aged children. ADHD patients with and without discharges are compared regarding age at admission, sex, global functioning, and distribution of ADHD subtypes. METHODS: The EEGs of 483 ADHD outpatients between 2 and 16 years meeting diagnostic criteria for ADHD according to Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) were evaluated prospectively. If rolandic spikes were present, separate sleep EEGs were performed to exclude a bioelectrical status epilepticus during slow-wave sleep. Results: Rolandic spikes were detected in the EEGs of 27 children (5.6%; 22 boys and five girls). Seizure rate during follow-up tended to be larger in children with rolandic spikes. No significant differences were found between ADHD patients with and without spikes regarding sex and global functioning. ADHD children with rolandic spikes came to our attention significantly earlier than did children without discharges and tended to exhibit more hyperactive-impulsive symptoms, evidenced in a larger proportion of the diagnosis of ADHD combined type than ADHD inattentive type. CONCLUSIONS: The frequency of rolandic spikes in children with ADHD is significantly higher than expected from epidemiologic studies. The question arises how ADHD symptoms are related to rolandic spikes in this ADHD subgroup. Possibly rolandic discharges or underlying, not fully understood mechanisms of epileptogenesis decrease the vulnerability threshold, advance the onset, or aggravate the course of ADHD.     

The Massachusetts General Hospital studies of gender influences on attention-deficit/hyperactivity disorder in youth and relatives.

With the single exception of SUDs, no statistically significant gender-by ADHD interactions were identified in the multiple, outcomes evaluated. These results suggest that with the exception of SUDs, ADHD expresses itself similarly in boys and girls relative to comparison subjects of the same gender, indicating that ADHD-associated impairments are correlates of ADHD in both genders. Gender differences, such as the higher prevalence of symptoms of inattention and lower rates of comorbidity with disruptive behavior disorders, major depression, and learning disability, were identified among the ADHD subjects. Because these differences were caused by the main effects of gender rather than effect modification of ADHD by gender, these findings indicate that girls were at the same relative risk for these adverse outcomes as boys, but that female gender resulted in a different clinical presentation than that affecting boys.The single statistically significant gender-by-ADHD interaction identified was the association between ADHD and SUDs (alcohol or drug abuse or dependence). ADHD in females was a more serious risk factor for SUDsthan it was in males was an unanticipated and surprising finding. In light of ongoing concerns regarding ADHD as a putative risk factor of SUDs [12],this finding may indicate that girls are particularly at risk in early adolescence. Considering that the age of onset of ADHD and SUDs are separated by at least a decade [13.14], this finding would support targeting of substance abuse prevention programs to girls with ADHD.Furthermore, results show that although the combined type of ADHDwas the predominant type in both genders, girls with ADHD were twice as likely as boys with ADHD to manifest the predominantly inattentive type of the disorder. Because symptoms of inattention are more covert than those of hyperactivity and impulsivity, their higher prevalence in girls with ADHDrelative to boys also may explain partially the markedly higher male-to-female ratios in referred versus nonreferred samples of children withADHD.This work also showed that the pattern of transmission of ADHD and comorbid disorders is not influenced by the proband's gender. This is true for the type of disorder transmitted and the degree of risk to relatives. The finding of no interactions between proband ADHD diagnosis and pro-band gender clearly rejects the idea that gender differences in comorbid disorders can be attributed to genes or other familial causes. Prior work had shown this to be true for the diagnosis of ADHD in relatives [15-20].Thus, gender and ADHD appear to be independent risk factors for comorbid psychopathology and for the familial transmission of comorbid psychopathology.In summary, these results suggest that gender was a limited effect modifier of ADHD as a risk factor for ADHD-associated dysfunction in referred children and adolescents. Gender, however, did impact the clinical presentation of the disorder. This was largely because girls with ADHDwere less likely than boys to have comorbid disruptive behavior problems and higher prevalence of symptoms of inattention. Because these features could result in gender-based referral bias unfavorable to girls, more work is needed in referred and nonreferred samples of youth with ADHD to more fully assess this issue. These results also showed similar patterns in the familial transmission of comorbid disorders in families of boys and girls with ADHD. Thus, although ADHD is associated with the familial trans-mission of comorbid disorders, the pattern of transmission is not influenced by the proband's gender. These similar patterns provide further evidence for the idea that, when ADHD is diagnosed in girls it corresponds to the same disorder diagnosed in boys.     

Serum zinc correlates with parent- and teacher- rated inattention in children with attention-deficit/hyperactivity disorder

OBJECTIVE: The aim of this study was to explore the relationship of zinc nutrition to the severity of attention-deficit/hyperactivity disorder (ADHD) symptoms in a middle-class American sample with well-diagnosed ADHD. Previous reports of zinc in ADHD, including two positive clinical trials of supplementation, have come mainly from countries and cultures with different diets and/or socioeconomic realities. METHOD: Children 5-10 years of age with DISC- and clinician-diagnosed ADHD had serum zinc determinations and parent and teacher ratings of ADHD symptoms. Zinc levels were correlated (Pearson's and multiple regression) with ADHD symptom ratings. RESULTS: Forty-eight children (37 boys, 11 girls; 33 combined type, 15 inattentive) had serum zinc levels with a median/mode at the lowest 30% of the laboratory reference range; 44 children also had parent/teacher ratings. Serum magnesium levels were normal. Nutritional intake by a parent-answered food frequency questionnaire was unremarkable. Serum zinc correlated at r = -0.45 (p = 0.004) with parent-teacher-rated inattention, even after controlling for gender, age, income, and diagnostic subtype, but only at r = -0.20 (p = 0.22) with CPT omission errors. In contrast, correlation with parent-teacher-rated hyperactivity-impulsivity was nonsignificant in the opposite direction. CONCLUSION: These findings add to accumulating evidence for a possible role of zinc in ADHD, even for middle-class Americans, and, for the first time, suggest a special relationship to inattentive symptoms. They do not establish either that zinc deficiency causes ADHD nor that ADHD should be treated with zinc. Hypothesis-testing clinical trials are needed.     

上海市闸北区5～15岁儿童注意缺陷多动障碍患病率及其影响因素的研究

目的了解上海市闸北区5~15岁儿童注意缺陷多动障碍（ADHD）的患病率特征及其影响因素。方法采用一般情况调查表和注意缺陷及多动症状调查表对上海市闸北区5~15岁儿童进行整群-分层抽样调查。共回收有效问卷9 900份,以美国精神障碍诊断和统计手册第4版ADHD的诊断标准对可疑患儿及其家长进行诊断性访谈,将ADHD患者分为注意缺陷为主型（ADHD-I）、多动-冲动为主型（ADHD-HI）和混合型（ADHD-C）,并分析ADHD的影响因素。结果 ADHD患病率为4.6%,其中ADHD-I型为2.4%,ADHD-HI型为0.4%,ADHD-C型为1.8%。男童患病率为6.6%,女童患病率为2.7%,男女患病率之比为2.41∶1。各年龄组ADHD各型的患病率存在差异,7~10岁组患病率最高（6.3%）。外地户籍儿童的患病率高于本市户籍儿童患病率。父母间的不同文化程度和人均月收入水平比较,其儿童的ADHD患病率差异有统计学意义。儿童月龄、性别及母亲低文化程度（初中及以下）是ADHD患病的影响因素。结论 ADHD-I型发病率高,7~10岁组患病率最高,儿童月龄、性别及母亲低文化程度影响ADHD患病率。     

Social impairment in girls with ADHD: patterns, gender comparisons, and correlates

OBJECTIVE: To investigate social impairment in girls with attention-deficit/hyperactivity disorder (ADHD), compare the social functioning of boys and girls with ADHD, and explore the association between social dysfunction and conditions comorbid with ADHD. METHOD: Four groups of index children were studied: 267 children (127 girls) with ADHD and 234 non-ADHD comparison children (114 girls). Groups were compared on social functioning, psychopathology, and demographic characteristics. RESULTS: Girls with ADHD manifested significant deficits in interpersonal functioning compared with girls without ADHD and evidenced a similar degree of social impairment compared with boys with ADHD. ADHD and associated comorbid disorders were significant correlates of specific domains of social dysfunction in boys and girls with ADHD. CONCLUSIONS: Interpersonal deficits are a major correlate of ADHD, irrespective of gender, and appear to stem from the behaviors associated with ADHD as well as behaviors characteristic of conditions comorbid with ADHD.     

The validity of the DSM-IV subtypes of attention-deficit/hyperactivity disorder

OBJECTIVE: To examine the validity of the three subtypes of ADHD defined by DSM-IV. METHOD: Studies published in English were identified through searches of literature databases. RESULTS: Estimates of the prevalence of ADHD have increased as a result of the introduction of DSM-IV criteria. Factor analytical and genetic studies provide some support for the validity of the distinction between the three subtypes. However, diagnosis of the combined subtype seems more reliable than the other two subtypes, although reliability is largely unknown for the latter. The hyperactive-impulsive subtype, the least common, differs from the other two subtypes in age distribution, association with other factors and neuropsychological parameters. Almost all treatment trials are based on participants with the combined type. CONCLUSION: Data supporting the validity of the inattentive and hyperactive-impulsive subtypes of ADHD a decade after the publication of DSM-IV are still scarce. Given that inattention is the hypothesized core ADHD symptom, it remains to be demonstrated that hyperactive-impulsive children who are not inattentive have the same condition. One of the main research deficits refers to data on treatment of the inattentive and hyperactive-impulsive subtypes.     

Should sluggish cognitive tempo symptoms be included in the diagnosis of attention-deficit/hyperactivity disorder?

OBJECTIVE: To determine the impact of including sluggish cognitive tempo items on the factor and latent class structure of attention-deficit/hyperactivity disorder (ADHD) subtypes in boys and girls. METHOD: Parent report of two sluggish cognitive tempo items on a population-based sample of 1430 female twins and 1414 male twins were analyzed along with parent report of the 18 DSM-IV ADHD items using principal components analysis and latent class analysis. RESULTS: The inclusion of the two sluggish cognitive tempo items resulted in distinct factor structures for boys and girls. For boys there were separate inattentive, hyperactive/impulsive, and sluggish factors. For girls there were separate inattentive/sluggish, hyperactive, and impulsive factors. In contrast, sluggish cognitive tempo items had minimal impact on the latent class structure of ADHD for both boys and girls. CONCLUSIONS: The inclusion of sluggish cognitive tempo items markedly changed ADHD symptom associations for boys and girls in a factor analytic framework. In contrast, latent class subtyping of ADHD shows limited impact of the inclusion of sluggish cognitive tempo items, emphasizing the very different assumptions about underlying continua of behavior rather than discrete classes that distinguish the two approaches.     

Symptoms of attention deficit hyperactivity disorder in children are associated with cortisol responses to psychosocial stress but not with daily cortisol levels

We tested associations of diurnal hypothalamic-pituitary adrenal axis (HPAA) activity and its response to stress with behavioral symptoms of Attention Deficit Hyperactivity Disorder (ADHD) among 272 eight-year-old children. We measured their diurnal salivary cortisol and salivary cortisol responses to the Trier Social Stress Test for Children (TSST-C). Mothers rated their child’s behavior with the ADHD-IV Rating Scale and the Child Behavior Checklist (CBCL). There were no significant associations between ADHD symptoms and diurnal cortisol concentrations. The boys with predominantly inattentive symptoms of ADHD (ADHD-I; scores at or above the 90th percentile) had 26% lower mean salivary cortisol levels during the TSST-C than the boys with scores below this cutoff. In the girls with symptoms of ADHD-I, initial salivary cortisol levels prior to the TSST-C were higher and fell more rapidly during and after the TSST-C, which was not seen in the remaining girls (P = 0.007 for interaction ‘ADHD-I × sampling time’). Controlling for Oppositional Defiant Disorder/Conduct Disorder and Anxiety Disorder or excluding children with these comorbid problems did not substantially affect these findings. We conclude that the boys and the girls with behavioral symptoms of ADHD-I had reduced HPAA responsiveness to stress, which is also seen in people after traumatic events or with chronic stress. Their diurnal cortisol rhythm was not affected. Thus, ADHD-I may be associated with dysregulation of the HPAA or reduced engagement with stressful stimuli.     

Partial replication of a DRD4 association in ADHD individuals using a statistically derived quantitative trait for ADHD in a family-based association test.

BACKGROUND: Previous research found an association between single nucleotide polymorphisms (SNPs) in the promoter region of DRD4 and statistically derived phenotypes generated from attention-deficit/hyperactivity disorder (ADHD) symptoms. We sought to replicate this finding by using the same methodology in an independent sample of ADHD individuals. METHODS: Four SNPs were genotyped in and around DRD4 in 2631 individuals in 642 families. We developed a quantitative phenotype at each SNP by weighting nine inattentive and nine hyperactive-impulsive symptoms. The weights were selected to maximize the heritability at each SNP. Once a quantitative phenotype was generated at each SNP, the screening procedure implemented in PBAT was used to select and test the five SNPs/genetic model combinations with the greatest power to detect an association for DRD4. RESULTS: One of the four SNPs was associated with the quantitative phenotypes generated from the ADHD symptoms (corrected p-values = .02). A rank ordering of the correlation between each of the ADHD symptoms and the quantitative phenotype suggested that hyperactive-impulsive symptoms were more strongly correlated with the phenotype; however, including inattentive symptoms was necessary to achieve a significant result. CONCLUSIONS: This study partially replicated a previous finding by identifying an association between rs7124601 and a quantitative trait generated from ADHD symptoms. The rs7124601 is in linkage disequilibrium (LD) with the SNPs identified previously. In contrast to the previous study, this finding suggests that both hyperactive-impulsive and inattentive symptoms are important in the association.     

Assessing adult attention-deficit/hyperactivity disorder: a Turkish version of the current symptoms scale

We report normative data for a Turkish translation of the Current Symptoms Scale (CSS), a screening measure of adult attention-deficit/hyperactivity disorder (ADHD). The CSS yields 3 scores reflecting diagnostic criteria for: (1) ADHD, predominantly hyperactive-impulsive type; (2) ADHD, predominantly inattentive type, and (3) ADHD, combined type. For comparison purposes, we also present normative data from a community sample in the United States. Central tendency, variability, and correlation patterns among Turkish subjects (n=181) were similar to patterns demonstrated by respondents in the United States (n=114). Mann-Whitney U tests revealed that the Turkish and US groups did not differ significantly on the subscales assessing inattentive and hyperactive-impulsive symptoms. Both versions demonstrated acceptable levels of internal consistency (Cronbach's alpha coefficients ranged from 0.65 to 0.78 for the Turkish version, and from 0.63 to 0.75 for the English version). The Turkish version of the CSS demonstrated excellent test- retest reliability. The test-retest coefficient for the CSS (total score) was 0.82. The inattentive type subscale also showed good test-retest reliability, with r=0.78. The test-retest coefficient for the hyperactive-impulsive type subscale was appreciably lower, with r=0.68; albeit, in the acceptable range. Investigators have determined that many adults, initially diagnosed with ADHD as children, continue to demonstrate clinically significant symptoms. Since adult ADHD is associated with a number of comorbid psychiatric conditions and treatment of the underlying attentional, executive, and impulse control difficulties is associated with a reduction in comorbid psychiatric symptoms, the routine screening for adult ADHD in psychiatric and mental health settings may be warranted.     

Acetyl-L-carnitine (ALC) in attention-deficit/hyperactivity disorder: a multi-site, placebo-controlled pilot trial

OBJECTIVE: To determine whether acetyl-L-carnitine (ALC), a metabolite necessary for energy metabolism and essential fatty acid anabolism, might help attention-deficit/hyperactivity disorder (ADHD). Trials in Down's syndrome, migraine, and Alzheimer's disease showed benefit for attention. A preliminary trial in ADHD using L-carnitine reported significant benefit. METHOD: A multi-site 16-week pilot study randomized 112 children (83 boys, 29 girls) age 5-12 with systematically diagnosed ADHD to placebo or ALC in weight-based doses from 500 to 1500 mg b.i.d. The 2001 revisions of the Conners' parent and teacher scales (including DSM-IV ADHD symptoms) were administered at baseline, 8, 12, and 16 weeks. Analyses were ANOVA of change from baseline to 16 weeks with treatment, center, and treatment-by-center interaction as independent variables. RESULTS: The primary intent-to-treat analysis, of 9 DSM-IV teacher-rated inattentive symptoms, was not significant. However, secondary analyses were interesting. There was significant (p = 0.02) moderation by subtype: superiority of ALC over placebo in the inattentive type, with an opposite tendency in combined type. There was also a geographic effect (p = 0.047). Side effects were negligible; electrocardiograms, lab work, and physical exam unremarkable. CONCLUSION: ALC appears safe, but with no effect on the overall ADHD population (especially combined type). It deserves further exploration for possible benefit specifically in the inattentive type.