Treatment of ADHD in neurofibromatosis type 1

Forty-six of 93 children with neurofibromatosis type 1 (NF1) were found to satisfy the diagnostic criteria for attention-deficit-hyperactivity disorder (ADHD). Detailed comparisons were made among 20 children with NF1 and ADHD (12 males, 8 females; mean age 10.7 years, SD 2.2), 26 control children with NF1 (15 males, 11 females; mean age 11.3 years, SD 2.3), 14 control children with ADHD (7 males; mean age 9.9 years, SD 1.9), and 14 normally developing control children (7 males; mean age 11.2 years, SD 2.8). Children with NF1 and ADHD had the lowest IQ scores among the four groups. Test of Variables of Attention (TOVA) scores were poorer in the NF1-ADHD and ADHD control groups than in the two non-ADHD groups. Those with NF1 and ADHD were rated significantly poorer on the Child Behavior Checklist (CBCL) than were the NF1 control group. By administrating low doses (5 to 15 mg) of methylphenidate to the NF1-ADHD group, significantly improved TOVA scores were obtained. One-year follow-up yielded significantly improved CBCL scores. Our results show a high incidence of ADHD in NF1 and support an association between ADHD and learning and social problems in children with NF1. It was demonstrated that stimulant medication can lead to improvement in cognitive, academic, and social problems of children with NF1 and ADHD.     

Process examination of executive function in ADHD: sex and subtype effects

To examine effects of group (Attention-Deficit/Hyperactivity Disorder [ADHD] versus Typically Developing [TD]), sex, and ADHD subtype on "process/optional" measures of executive functioning, children (n = 123; 54 ADHD, 69 TD) aged 8-16 completed subtests from the D-KEFS. No group, sex, or ADHD subtype effects were found on optional measures from the Trail Making, Color-Word Interference, and Tower tests. A significant interaction was found for Verbal Fluency Total Repetition Errors; boys with Combined/Hyperactive-Impulsive (ADHD-C/HI) type ADHD performed better than ADHD-C/HI girls, whereas girls with Inattentive type ADHD (ADHD-I) performed better than ADHD-I boys. Overall, children with ADHD did not differ from TD on most optional measures from the D-KEFS. When sex and ADHD subtype were considered, children with the subtype of ADHD less common for sex were at greater risk for poorer performance.     

Are children with ADHD predominantly inattentive and combined subtypes different in terms of aspects of everyday attention?

The validity of the DSM-IV subtypes is a recurring diagnostic debate in attention deficit/hyperactivity disorder (ADHD). Laboratory measures, such as the test of everyday attention for children (TEA-Ch) can help us address this question. TEA-Ch is a test battery covering different aspects of everyday attention relating to selective and sustained attention and attentional control. The aim of the current study was to investigate whether this instrument can differentiate between combined (ADHD-C) and inattentive subtype (ADHD-I) of ADHD. Subjects were recruited from a multidisciplinary ADHD outpatient unit and tested free of medication. Sixty-four children with a diagnosis of ADHD were included (38 with ADHD-C; 26 with ADHD-I). The control group was 76 children recruited from primary and secondary schools. Children with ADHD performed worse than controls on 6 out of 9 TEA-Ch subtests. However a regression analysis revealed that TEA-Ch subtests made only a marginal contribution to the correct classification of ADHD, once the effects of IQ and age are controlled. Confirmatory factor analysis in our ADHD group demonstrated that the three factor structure achieved a poor fit. More detailed analysis suggested that inferior performance on the tasks designed to test vigilance was not the result of deficient-sustained attention. ADHD-C and ADHD-I showed very few differences across tasks. In conclusion, our results provided not much support for the value of the ADHD-C and ADHD-I distinction in predicting difficulties in everyday attention.     

Changes in Behaviour Symptoms of Patients with Attention Deficit/Hyperactivity Disorder during Treatment: Observation from Different Informants

Objective

The aim of this study was to determine changes in behaviour among patients with attention deficit/hyperactivity disorder (ADHD) by different informants during treatment in the clinical setting.

Methods

Seventy-nine patients with ADHD were recruited. They completed 12-months of treatment with oral short-acting methylphenidate, two-to-three times per day, at a dose of 0.3-1.0 mg/kg. Among the 79 patients (mean age, 9.1±1.9 years), 39 were classified as the ADHD-C/H type (hyperactive-impulsive type and combined type) and 40 as the ADHD-I type (inattentive type). At baseline, and after 12 months, their behaviour was assessed using the Child Behaviour Checklist (CBCL), Teacher''s Report Form (TRF), ADHD Rating Scale (ADHD-RS), and Clinical Global Impression-Severity (CGI-S).

Results

Patients classified as the ADHD-C/H type had higher scores on three CBCL subscales, on the ADHD-RS and CGI-S compared to the ADHD-I type patients. After 12-months of treatment, for all patients, there were significant improvements in the four subscales of the TRF as well as the ADHD-RS and CGI-S scores, but not on the CBCL. In addition, the patients with the ADHD-C/H type had greater improvements on the four subscales of the TRF after treatment. However, there were no differences noted on the CBCL, ADHD-RS and CGI-S.

Conclusion

The results of this study showed that during treatment, in the clinical setting, there are different assessments of behaviour symptoms, associated with ADHD, reported by different informants. Assessments of behaviour profiles from multiple informants are crucial for establishing a fuller picture of patients with ADHD.     

Differential perinatal risk factors in children with attention-deficit/hyperactivity disorder by subtype

We compared the attention-deficit/hyperactivity disorder(ADHD) combined subtype (ADHD-C) to the ADHD inattentive subtype (ADHD-I) in terms of genetic, perinatal, and developmental risk factors as well as clinical and neuropsychological characteristics. A total of 147 children diagnosed with ADHD between the ages of 6 and 15 years participated in this study. The parents of the children completed the structured diagnostic interview, the ADHD Rating Scale-IV, the Children’s Behavior Checklist, and structured questionnaires on perinatal risk factors, and the children underwent a neuropsychological test and were genotyped. A total of 502 children without ADHD were recruited from the community as a healthy control group. The ADHD-C children showed more severe externalizing symptoms, showed more deficits in a continuous performance test, and were more likely to have comorbid disorders. Maternal stress during pregnancy, postpartum depression, and changes in the primary caretaker during first 3 years were significantly associated with both ADHD-I and ADHD-C. The ADHD-I group was less likely to have received regular prenatal check-ups and more likely to have had postnatal medical illness than the ADHD-C group. There were no significant differences in the genotype frequencies of the dopamine transporter (DAT1) and the serotonin transporter –linked polymorphic region (5-HTTLPR) polymorphisms between ADHD-I and ADHD-C groups. This study shows that the inattentive subtype of ADHD is different from the combined subtype in many parameters including severity of symptoms, comorbidity, neuropsychological characteristics, and environmental risk factors.     

ADHD, neurological correlates and health-related quality of life in severe pediatric epilepsy

PURPOSE: ADHD is reported as a frequent comorbidity in pediatric epilepsy. We aimed to clarify the prevalence of ADHD, its neurological correlates and the role of ADHD in health-related quality of life (HRQOL) in children with severe epilepsy. METHOD: Data from the ADHD Rating Scale-IV (ADHD-RS-IV) from 203 children (mean age = 11.8, SD=3.8) from a tertiary center serving children with severe epilepsy were reviewed. RESULTS: Inattention was frequently elevated in the sample (40% vs. 18% for hyperactivity-impulsivity). Age of onset, epilepsy duration, and seizure frequency were not related to severity of inattention or hyperactivity-impulsivity. Over 60% of children met screening criteria for ADHD-Inattentive subtype (ADHD-I) or ADHD-Combined Inattentive/Hyperactive-Impulsive subtype (ADHD-C). Compared to ADHD-I, ADHD-C was associated with earlier onset of seizures, generalized epilepsy, lower adaptive level, and in normally developing children, a higher degree of intractability compared to ADHD-I. ADHD-I was more prevalent in localization-related epilepsy, and there was a trend for a higher use of AEDs with cognitive side effects in this group. ADHD was associated with poor HRQOL: children with ADHD-I and ADHD-C had a two- and four-fold likelihood of low HRQOL, respectively, compared to non-ADHD children. CONCLUSIONS: Children seen at tertiary care centers for severe epilepsy are at high risk for attention problems and ADHD, and ADHD is a significant predictor of poor HRQOL in epilepsy, particularly in the case of ADHD-C. ADHD occurring in the context of severe epilepsy appears to be associated with specific neurological characteristics, which has implications for comorbidity models of ADHD and epilepsy.     

Psychometric study of the test of variables of attention: preliminary findings on Taiwanese children with attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a common mental disorder in children. Unfortunately, reliable means of measuring attention and impulsivity to help with diagnoses are scarce. The test of variables of attention (TOVA) is a computer-administered continuous performance test measuring attention and impulsivity, designed to avoid confounding arising from language processing skills or short-term memory problems. Some evidence has indicated the TOVA can be useful in diagnosing ADHD. This study examines its validity and reliability in helping diagnose Taiwanese ADHD children. The study included 31 ADHD children (24 males, seven females) from a northern Taiwan children's hospital and 30 normal controls (18 males, 12 females) from the local community. The TOVA and the Child Behavior Checklist (CBCL) were administered to all children. TOVA scores for omissions, commissions, response time, response time variability, D' and ADHD scores were analyzed. Results showed a mean internal consistency of 0.81 for all six TOVA variables across conditions, with moderate convergent and discriminant validities. Groups showed significant differences in response time variability, D' and ADHD scores, with the normal group outperforming the ADHD group. Significant group differences were also found in all CBCL subscale scores except somatic complaints. The ADHD group obtained a clinically significant score on the hyperactivity subscale of the CBCL. The findings partially support the usefulness of the TOVA in assessing attention and impulsivity problems for a Taiwanese sample. Future studies should increase the sample size, use multiple measures, and collect behavior ratings from both parents and teachers.     

Differences between attention-deficit disorder with and without hyperactivity: a 1H-magnetic resonance spectroscopy study

Using proton magnetic resonance spectroscopy ((1)H-MRS) to investigate possible neurometabolic differences between the predominantly inattentive subtype (ADHD-I), the combined subtype (ADHD-C) and normal controls. Proton spectra were acquired bilaterally on the lenticular nucleus in 20 schoolboys having ADHD and 10 matched controls. The boys with ADHD were divided into ADHD-C subtype (n=10) and ADHD-I subtype (n=10) according to DSM-IV criteria. The peaks of N-acetylaspartate (NAA), Choline moieties (Cho), myo-inositol (mI), creatine (Cr) and alpha-Glx were measured and their ratios to Cr were calculated. One-way ANOVA and post-hoc Bonferroni tests were used to detect the difference of the peak-area ratios of NAA, Cho, mI, and alpha-Glx to Cr among the three groups. There was a significant overall group difference in the NAA/Cr ratio both in the right and left lenticular nucleus (right: P=0.002; left: P=0.003). Only the ADHD-C subtype group showed a significant difference with controls (right: P=0.001; left: P=0.003) the right lenticular nucleus, the NAA/Cr ratio in the ADHD-C group was significantly lower than that in the ADHD-I group (P=0.012). In the left lenticular nucleus, the NAA/Cr ratio in the ADHD-C group showed a significant trend compared to the ADHD-I group (P=0.06). This study demonstrated the existence of measurable difference between children with ADHD-C and ADHD-I using (1)H-MRS.     

Co-occurrence of developmental delays among preschool children with attention-deficit-hyperactivity disorder

The aim of this study was to provide a comprehensive profile of the sensory, motor, language, and intellectual functioning of a non-referred community sample of 49 preschool children with attention-deficit-hyperactivity disorder (ADHD; 39 males, 10 females; mean age 4y 7mo [SD 7mo]; range 3y 10mo-6y) and 48 typically developing children (38 males, 10 females; mean age 4y 8mo [SD 6mo]; range 3y 11mo-6y) matched by age, sex, and maternal education who underwent a broad battery of neurodevelopmental tests. The results showed that the scores of the ADHD group were significantly lower than the comparison group on all measures. In addition, 23 (47%) of the children with ADHD had clinically significant co-occurring deficits in two or more areas. Logistic regression indicated that the only significant predictors of group classification were scores of verbal intelligence and motor and sensory functioning, accounting for 44.1% of the variance. These findings suggest that preschool children with ADHD have multiple developmental deficits over and above the core symptoms of ADHD and emphasize the importance of evaluating the sensorimotor functioning of preschool children with ADHD symptoms.     

Immediate effects of methylphenidate on cognitive attention skills of children with attention-deficit-hyperactivity disorder

This study investigated the immediate effects of stimulant medication (methylphenidate) on cognitive attention processes in children with attention-deficit-hyperactivity disorder (ADHD). Thirteen males and two females (mean age 9 y 5 mo, SD 18.3 mo) with a diagnosis of ADHD and who were to be prescribed methylphenidate were assessed twice on one day with the Test of Everyday Attention for Children, a neuropsychological battery designed to tap different aspects of cognitive attention. Between assessments, the children were administered methylphenidate (10 mg). Each child had at least average intelligence (IQ 80 or over, as measured by the Wechsler Intelligence Scale for Children-III UK) and was on no other medication. A group of 16 children, who were matched for age, sex, and intelligence, also performed the cognitive tests twice on the same day to control for practice effects of testing. At the first assessment, children with ADHD demonstrated significant impairments in several aspects of cognitive attention in comparison with the control group, particularly sustained attention. After administration of methylphenidate for the children with ADHD, they showed significant improvements in their performance on measures of cognitive attention compared to controls. The immediate effects of methylphenidate and the significance of measuring cognitive aspects of attention as well as behavioural measures are discussed.     

Young adults with attention deficit hyperactivity disorder: subtype differences in comorbidity, educational, and clinical history

The present study sought to examine subtype differences in comorbidity and in antisocial, educational, and treatment histories among young adults (ages 17-27) with attention deficit hyperactivity disorder (ADHD). Comparisons were made between ADHD Combined Type (ADHD-C; N = 60) and Predominantly Inattentive Type (ADHD-I; N = 36) relative to each other and to a community control group of 64 adults. Both ADHD groups had significantly less education, were less likely to have graduated from college, and were more likely to have received special educational placement in high school. Both groups also presented with a greater likelihood of dysthymia, alcohol dependence/abuse, cannabis dependence/abuse, and learning disorders, as well as greater psychological distress on all scales of the SCL-90-R than the control group. Both ADHD groups were more likely to have received psychiatric medication and other mental health services than control adults. In comparison with ADHD-I, adults with ADHD-C differed in only a few respects. The C-type adults were more likely to have oppositional defiant disorder, to experience interpersonal hostility and paranoia, to have attempted suicide, and to have been arrested than the ADHD-I adults. These results are generally consistent with previous studies of ADHD in children, extend these findings to adults with ADHD, and suggest that the greater impulsivity associated with the ADHD-C subtype may predispose toward greater antisocial behavior and its consequences than does ADHD-I type in adults.     

Sex differences in tactile defensiveness in children with ADHD and their siblings

Tactile defensiveness (TD) is a disturbance in sensory processing and is observed in some children with attention-deficit-hyperactivity disorder (ADHD). TD has been examined in male children with ADHD and in children with ADHD without differentiating by sex. As males and females with ADHD may differ in the clinical expression of the disorder and associated deficits, the aim of this study was to examine sex differences in TD in males and females with ADHD. Non-affected siblings were also examined to investigate familiality of TD. The Touch Inventory for Elementary-School-Aged Children was administered to 47 children with ADHD (35 males, 12 females; mean age 9y 8mo [SD 1y 11mo]), 36 non-affected siblings (21 males, 15 females; mean age 8y 10mo [SD 2y 4mo]), and 35 control children (16 males, 19 females; mean age 9y 5mo [SD 6mo]). Results indicated that females with ADHD displayed higher levels of TD than males with ADHD (who did not differ from control males). This suggests that TD is sex specific and may contribute to the identification of ADHD in females, thus improving diagnostic and therapeutic strength in this under-referred group. Non-affected siblings were unimpaired, regardless of sex, which suggests that TD is specific to the disorder and not part of a familial risk for ADHD.     

Differences in hypothalamic–pituitary–adrenal axis functioning among children with ADHD predominantly inattentive and combined types

Some evidence suggests that the HPA axis may be dysfunctional in children with attention-deficit/hyperactivity disorder (ADHD). The aim of this study was to investigate whether a different pattern of HPA axis activity is found between the inattentive (I) and combined (C) subtypes of ADHD, in comparison with healthy control children. A total of 100 prepubertal subjects [52 children with ADHD combined type (ADHD-C), 23 children with ADHD predominantly inattentive type (ADHD-I), and 25 healthy control subjects] were studied. The effects of stress were studied by comparing cortisol responses to a psychosocial stressor, consisting of a public speaking task. Children with ADHD-I showed an elevated cortisol response to the psychosocial stressor, in contrast to children with ADHD-C who showed a blunted cortisol response to the psychosocial stressor. When a distinction was made between responders and non-responders (a subject was classified as a responder when there was an increase in cortisol reactivity), hyperactivity symptoms were clearly related to a lower cortisol reactivity to stress. The results indicate that a low-cortisol responsivity to stress may be a neurobiological marker for children with ADHD-C, but not for those with ADHD-I. Directions for future research and clinical implications are discussed.     

Effect of subtype and psychiatric comorbidities on methylphenidate treatment in adults with attention-deficit hyperactivity disorder

The present study was intended to examine the efficacy of immediate-release methylphenidate (MPH IR) in the treatment of adults with attention-deficit hyperactivity disorder (ADHD) under consideration of subtype according to DSM-IV criteria and psychiatric comorbidity. After baseline assessment over 3 weeks, 47 patients aged 18-59 years with combined ADHD (ADHD-C) (n=27) and predominantly inattentive ADHD (ADHD-I; n=20) were treated in an open, uncontrolled design with an average dose of 0.5 mg MPH IR per kg over 7 weeks. Thirty-nine patients finished the study. The two groups did not differ in response to treatment with regard to ADHD symptoms (very good to good outcome in ADHD-C 73.9%, in ADHD-I 66.7%) or cognitive measures (sustained attention, information processing speed, divided attention). However, ADHD patients with psychiatric comorbidities had significantly worse outcome: total ADHS scores on the T2 Brown Attention Deficit Disorder Scales (BADDS) were 66.2+/-15.5 with psychiatric comorbidity and 51.7+/-13.7 without (P=0.04), despite significantly higher doses of MPH IR (0.56+/-0.17 mg/kg vs 0.46+/-0.13 mg/kg; P=0.004). This effect was mainly seen in the patients with clinically significant depressive symptoms (Beck Depression Inventory > or =18), who clearly benefited less from treatment (total T2 BADDS scores with depressive symptoms 70.7+/-15.9 and without depressive symptoms 48.1+/-21.2; P=0.001).     

Gait function in newly diagnosed children with autism: Cerebellar and basal ganglia related motor disorder

We investigated gait in newly diagnosed children with autism. From our previous study with 6- to 14-year-olds, we hypothesized that motor symptoms indicative of basal ganglia and cerebellar dysfunction would appear across the developmental trajectory of autism. Two groups were recruited: children with autism (eight males, three females; mean age 5 y 10 mo [SD 9 mo]; range 4 y 4 mo-6 y 9 mo) and a comparison group of typically developing children (eight males, three females; mean age 5 y 9 mo [SD 1 y 1 mo]; range 4 y 3 mo-7 y 2 mo). The GAITRite Walkway was used to gather data from average gait and intra-walk measurements. Experienced physiotherapists analyzed gait qualitatively. Groups were matched according to age, height, weight, and IQ; although not statistically significant, IQ was lower in the group with autism. Spatiotemporal gait data for children with autism were compatible with findings from patients with cerebellar ataxia: specifically, greater difficulty walking along a straight line, and the coexistence of variable stride length and duration. Children with autism were also less coordinated and rated as more variable and inconsistent (i.e. reduced smoothness) relative to the comparison group. Postural abnormalities in the head and trunk suggest additional involvement of the fronto-striatal basal ganglia region. Abnormal gait features are stable across key developmental periods and are, therefore, promising for use in clinical screening for autism.     

Differentiation of attention-deficit/hyperactivity disorder subtypes: application of a neuropsychological model of attention

This study represents a neuropsychological attempt to differentiate subtypes of Attention Deficit/Hyperactivity Disorder (ADHD). Participants (N = 80) were grouped by gender and ADHD subtype-Predominantly Inattentive (ADHD-I) versus Combined (ADHD-C)-resulting in four age-matched groups. Statistical analysis revealed significant differences in performance on selective attention tasks for those with ADHD-I and those with ADHD-C. Relative to their counterparts without hyperactivity, participants with ADHD-C earned disproportionately lower scores on tasks associated with executive control. Both subgroups with ADHD-I and ADHD-C demonstrated significant difficulty on some tasks assessing complex mental operations relative to age-standardized normative data. Discriminant analysis revealed that a combination of five neuropsychological measures discriminated between the ADHD-I and ADHD-C subgroups with 80% accuracy. Results provide support for the notion of the Predominantly Inattentive and Combined subtype classifications as defined by the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (American Psychiatric Association, 1994). Further, findings from this study lend preliminary support for the utility of a neurophysiologically sensitive model of attention in the differentiation of these subtypes.     

Sleep and daytime function in adults with attention-deficit/hyperactivity disorder: subtype differences

ObjectivesAlthough sleep disorders have been reported to affect more than half of adults with attention-deficit/hyperactivity disorder (ADHD), the association between sleep and ADHD is poorly understood. The aims of our study were to investigate sleep-related variables in adults with ADHD and to assess if any differences exist between ADHD of the predominantly inattentive (ADHD-I) and combined (ADHD-C) subtypes.MethodsWe used the Epworth sleepiness scale (ESS), the Pittsburgh Sleep Quality Index (PSQI), and the fatigue severity scale (FSS) to collect data on daytime sleepiness, sleep quality, and fatigue in 126 subjects (45 ADHD-I and 81 ADHD-C subjects).ResultsApproximately 85% of subjects reported excessive daytime sleepiness or poor sleep quality. The most common sleep concerns were initial insomnia, interrupted sleep, and feeling too hot. When examining ADHD subtype differences, ADHD-I subtypes reported poorer sleep quality and more fatigue than ADHD-C subtypes. Partial correlation analyses revealed that interrelationships between sleep quality, daytime sleepiness, and fatigue differ between ADHD subtypes; in ADHD-I subtypes fatigue was associated with sleep quality, while in the ADHD-C subtypes fatigue was associated with both sleep quality and daytime sleepiness. There also appears to be a subtype × gender interaction that affects the perception of fatigue, as subjective fatigue was markedly higher in ADHD-I women than in ADHD-C women.ConclusionAltogether our data indicate that the interplay of variables associated with daytime function and sleep varies between ADHD subtypes. This finding may have considerable relevance in the management and pathophysiologic understanding of ADHD, and thus lead to tailored treatments for ADHD subtypes.     

Autism and ADHD: Overlapping and discriminating symptoms

Children with ADHD and autism have some similar features, complicating a differential diagnosis. The purpose of our study was to determine the degree to which core ADHD and autistic symptoms overlap in and discriminate between children 2-16 years of age with autism and ADHD. Our study demonstrated that 847 children with autism were easily distinguished from 158 children with ADHD. All children with autism had 15 or more of the 30 Checklist for Autism Spectrum Disorder symptoms (mean 22), and none of the children with ADHD did (mean 4). Three of the symptoms were present only in children with autism. Almost all 30 symptoms were found in over half of the children with autism, whereas none were present in the majority of children with ADHD-Inattentive type (ADHD-I) or in children with ADHD-Combined type (ADHD-C) without comorbid oppositional-defiant disorder. In contrast, ADHD symptoms were common in autism. Children with low and high functioning autism and ADHD-C did not differ on maternal ratings of attention deficit, impulsivity, and hyperactivity. For children with normal intelligence, nonsignificant differences were found between children with autism, ADHD-C, and ADHD-I on neuropsychological tests including measures of attention, working memory, processing speed, and graphomotor skills.     

No association between the 2D:4D fetal testosterone marker and multidimensional attentional abilities in children with ADHD

Aim It has been suggested that high levels of prenatal testosterone exposure are implied in the aetiology of attention‐deficit–hyperactivity disorder (ADHD). This study examined the association between the ratio of the length of the second and fourth digits (2D:4D ratio), a marker of fetal testosterone exposure, and the presence of ADHD‐related cognitive and behavioural problems in children with ADHD and in typically developing comparison individuals. Method A clinically referred group of 64 children who fulfilled DSM‐IV‐TR criteria for ADHD (47 males, 17 females; mean age 8y 8mo, SD 1y 8mo, range 7–12y) and 46 comparison children (25 males, 21 females; mean age 9y 2mo; SD 1y 10mo, range 7–12y) were included in the study. The length of the second and fourth digits was measured by two independent raters. The Child Behaviour Checklist (CBCL) and the Test of Everyday Attention for Children (TEA‐Ch) were used to assess behavioural problems and different aspects of attention. Results No group differences in 2D:4D ratio were observed between children with (combined, inattentive, or hyperactive‐impulsive subtype of) ADHD and comparison children. The ratio did not show the postulated relation with cognitive and behavioural aspects of ADHD. Interpretation These findings challenge the hypothesis that fetal testosterone exposure plays a prominent role in the aetiology of ADHD.     

Attention-deficit/hyperactivity disorder with obstructive sleep apnea: a treatment outcome study

BACKGROUND: Children diagnosed with attention-deficit/hyperactivity disorder (ADHD), based on Diagnostic and Statistical Manual of Mental Disorders, Fourth edition (DSM-IV) criteria, may also have obstructive sleep apnea (OSA), but it is unclear whether treating OSA has similar results as methylphenidate (MPH), a commonly used treatment for ADHD. METHODS: This study enrolled 66 school-age children, referred for and diagnosed with ADHD, and 20 healthy controls. Polysomnography (PSG) performed after ADHD diagnosis showed the presence of mild OSA. After otolaryngological evaluation, parents and referring physicians of the children could select treatment of ADHD with MPH, treatment of OSA with adenotonsillectomy or no treatment. Systematic follow-up was performed six months after initiation of treatment, or diagnosis if no treatment. All children had pre- and post-clinical interviews; pediatric, neurologic, psychiatric and neurocognitive evaluation; PSG; ADHD rating scale, child behavior checklist (CBCL) filled out by parents and teacher; test of variables of attention (TOVA); and the quality of life in children with obstructive sleep disorder questionnaire (OSA-18). RESULTS: ADHD children had an apnea-hypopnea index (AHI)>1<5 event/hour; 27 were treated with MPH, 25 had adenotonsillectomy, and 14 had no treatment. The surgical and MPH groups improved more than the non-treatment group. When comparing MPH to post-surgery, the PSG and questionnaire sleep variables, some daytime symptoms (including attention span) and TOVA subscales (impulse control, response time and total ADHD score) improved more in the surgical group than the MPH group. The surgical group had an ADHD total score of 21.16+/-7.13 on the ADHD rating scale (ADHD-RS) post-surgery compared to 31.52+/-7.01 pre-surgery (p=0.0001), and the inattention and hyperactivity subscales were also significantly lower (p=0.0001). Finally, the results were significantly different between surgically and MPH-treated groups (ADHD-RS p=0.007). The surgical group also had a TOVA ADHD score lower than -1.8 and close to those obtained in normal controls. CONCLUSION: A low AHI score of >1 considered abnormal is detrimental to children with ADHD. Recognition and surgical treatment of underlying mild sleep-disordered breathing (SDB) in children with ADHD may prevent unnecessary long-term MPH usage and the potential side effects associated with drug intake.