Attention-deficit/hyperactivity Disorder In Girls Research Articles

Sex differences in genetic and environmental influences on DSM-III-R attention-deficit/hyperactivity disorder.

Approximately 5% of children are affected by attention-deficit/hyperactivity disorder (ADHD), and more boys are affected than girls. This study examined the magnitude of genetic and environmental influences on ADHD and several questions regarding sex differences in its prevalence and liability. The participants were 2,391 twin and sibling pairs from Australia, ages 3-18. ADHD symptoms in the general population were highly heritable (h2 = .85-.90), as were deviant ADHD scores in the selected population. The magnitude of familial influences was similar for boys and girls, although there were shared environmental influences on ADHD in girls but not boys and dominance genetic influences on ADHD in boys but not girls. Specific genetic and environmental influences were highly similar for boys and girls. Evidence supported the polygenic multiple threshold model rather than the constitutional variability model of sex differences in ADHD.

ADHD in Girls: Clinical Comparability of a Research Sample

ObjectiveThe investigation of attention-deficit/hyperactivity disorder (ADHD) in girls raises complex questions of referral bias and selection criteria. The authors sought to determine whether they could recruit a research sample of comparably affected girls using a combination of sex-independent diagnostic criteria and sex-normed cutoffs on teacher ratings. They also report on the largest placebo-controlled crossover comparison of methylphenidate and dextroamphetamine in girls with ADHD. MethodSubjects were 42 girls with DSM-III-R/DSM-IV ADHD (combined type) contrasted to 56 previously studied boys with ADHD on comorbid diagnoses, behavioral ratings, psychological measures, psychiatric family history, and stimulant drug response. ResultsGirls with ADHD were statistically indistinguishable from comparison boys on nearly all measures. Girls exhibited robust beneficial effects on both stimulants, with nearly all (95%) responding favorably to one or both drugs in this short-term trial. Dextroamphetamine produced significantly greater weight loss than methylphenidate. ConclusionsThis highly selected group of ADHD girls was strikingly comparable with comparison boys on a wide range of measures. The results confirm that girls with ADHD do not differ from boys in response to methylphenidate and dextroamphetamine and that both stimulants should be tried when response to the first is not optimal. J. Am. Acad. Child Adolesc. Psychiatry, 1999, 38(1):40–47.

Cerebral Glucose Metabolism in Adolescent Girls With Attention-Deficit/Hyperactivity Disorder

Low cerebral metabolic rates for glucose (CMRglc) have been reported in a small sample of girls with attention-deficit/hyperactivity disorder (ADHD). This study was an effort to replicate this finding in a larger independent sample. Using positron emission tomography and [18F]fluorodeoxyglucose, CMRglc were compared between 10 girls with ADHD (14.10 +/- 1.91 years) and 11 normal girls (14.3 +/- 1.70 years). Global CMRglc was similar between ADHD and control girls. Lateralization of normalized CMRglc differed significantly between ADHD and control girls in parietal and subcortical regions, with rCMRglc lower on the left than on the right side in girls with ADHD, and conversely in control girls. The sylvian area of the parietal region and the anterior putamen of the subcortical region were the main contributors to this effect. Normalized rCMRglc of the hippocampus was higher in ADHD than in control girls. Sexual maturation was the only clinical characteristic that differed between present and previous samples, and it correlated with global CMRglc. Although failing to confirm abnormally low CMRglc in girls with ADHD, this study suggested that (1) functional interactions between sex and brain development may contribute to ADHD pathophysiology, and (2) sexual maturation should be controlled in future CMRglc studies of adolescent girls.

Gender Differences in ADHD: A Meta-Analysis and Critical Review

To quantitatively review and critically evaluate literature examining gender differences in attention-deficit hyperactivity disorder (ADHD). A meta-analysis of relevant research based on 18 studies meeting inclusion criteria was performed. Domains evaluated included primary symptomatology, intellectual and academic functioning, comorbid behavior problems, social behavior, and family variables. Gender differences were not found in impulsivity, academic performance, social functioning fine motor skills, parental education, or parental depression. However, compared with ADHD boys, ADHD girls displayed greater intellectual impairment, lower levels of hyperactivity, and lower rates of other externalizing behaviors; it was not possible to evaluate the extent to which referral bias affected these findings. Some gender differences were clearly mediated by the effects of referral source; among children with ADHD identified from nonreferred populations, girls with ADHD displayed lower levels of inattention, internalizing behavior, and peer aggression than boys with ADHD, while girls and boys with ADHD identified from clinic-referred samples displayed similar levels of impairment on these variables. The need for future research examining gender differences in ADHD is strongly indicated, with attention to methodological limitations of the current literature, including the potential confounding effects of referral bias, comorbidity, developmental patterns, diagnostic procedures, and rater source.

Gender Differences in ADHD: A Meta-Analysis and Critical Review

Objective To quantitatively review and critically evaluate literature examining gender differences in attention-deficit hyperactivity disorder (ADHD). Method A meta-analysis of relevant research based on 18 studies meeting inclusion criteria was performed. Domains evaluated included primary symptomatology, intellectual and academic functioning, comorbid behavior problems, social behavior, and family variables. Results Gender differences were not found in impulsivity, academic performance, social functioning, fine motor skills, parental education, or parental depression. However, compared with ADHD boys, ADHD girls displayed greater intellectual impairment, lower levels of hyperactivity, and lower rates of other externalizing behaviors; it was not possible to evaluate the extent to which referral bias affected these findings. Some gender differences were clearly mediated by the effects of referral source; among children with ADHD identified from nonreferred populations, girls with ADHD displayed lower levels of inattention, internalizing behavior, and peer aggression than boys with ADHD, while girls and boys with ADHD identified from clinic-referred samples displayed similar levels of impairment on these variables. Conclusions The need for future research examining gender differences in ADHD is strongly indicated, with attention to methodological limitations of the current literature, including the potential confounding effects of referral bias, comorbidity, developmental patterns, diagnostic procedures, and rater source.

A Pilot Study of Neuropsychological Function in Girls With ADHD

Attention-deficit hyperactivity disorder (ADHD) is known to have neuropsychological consequences that are evident from psychological tests and from measures of school failure. However, most available data are based on studies of boys. Our goal was to assess, in this pilot study, whether ADHD in girls expressed neuropsychological features similar to those found in boys. Subjects were 43 girls, aged 6 to 17 years, with DSM-III-R ADHD and 36 comparison girls without ADHD. Information on neuropsychological performance was obtained in a standardized manner blind to clinical status. Girls with ADHD were significantly more impaired on estimated IQ than comparison girls despite being matched on other demographic variables. Relative to comparison girls, the girls with ADHD were also significantly more impaired on the Freedom From Distractibility subtests of the WISC-R and on arithmetic and reading achievement scores. Although their mean performance on executive function tests was generally poorer than that of control girls, there were no statistically significant differences on these measures. Girls with ADHD have impairments in some tests of attention and achievement. However, neuropsychological performance on tests of executive function was less impaired than that previously documented in boys with ADHD. If confirmed in a larger sample, these findings suggest that girls with ADHD may be less vulnerable to executive function deficits than boys.

Sex differences in school-aged children with pervasive attention deficit hyperactivity disorder.

This study investigated 54 children (37 boys and 17 girls) with cross-situational attention deficit hyperactivity disorder (ADHD) to determine whether there are sex differences in the expression of either the primary or secondary symptomatology of ADHD. Results indicated that the male and female ADHD groups were strikingly similar on all measures of primary (impulsivity, inattention, and overactivity) and secondary (learning problems, externalizing symptoms, internalizing symptoms, peer relationship difficulties, and self-perceptions) symptomatology included in this study. The lack of significant sex differences conflicts with prior reports in the literature, and these conflicting results are discussed in terms of differences in inclusion criteria. Implications for understanding the long-term outcome of ADHD in girls are also discussed.