Gender Differences in the Behavioral Symptoms and Neuropsychological Performance of Patients with Attention-Deficit/Hyperactivity Disorder Treated with Methylphenidate: A Two-Year Follow-up Study.
OBJECTIVE
This study investigated the gender differences in behavioral symptoms, as rated by various informants, and in neuropsychological performance, among patients with attention-deficit/hyperactivity disorder (ADHD) treated with methylphenidate during 24 months in a clinical setting.


METHODS
Study participants comprised 128 boys (mean age: 13.2±2.4 years) and 26 girls (mean age: 12.8±1.0 years) with ADHD. All patients were prescribed short-acting oral methylphenidate, taken two or three times daily; each dose ranged between 0.3 and 1.0 mg/kg. At the baseline and 6, 12, 18, and 24 months later, behavioral symptoms were evaluated using the parent and teacher forms of the Swanson, Nolan, and Pelham Version IV (SNAP-IV) scale for ADHD and the ADHD Rating Scale (completed by a child psychiatrist). In addition, neuropsychological function was assessed using the Test of Variables of Attention (TOVA) at each interval.


RESULTS
Although both the boys and girls exhibited a significant decrease in the ADHD symptoms observed by parents and clinicians, the girls improved more than the boys did. Based on the teacher reports, neither the boys nor the girls exhibited significant decreases in ADHD symptoms. The symptoms rated by teachers were more severe in the boys than in the girls throughout the first 12 months; however, the gender difference lessened after 12 months. Based on the TOVA assessment, a composite score (containing response time, response time variability, and ADHD score obtained using the TOVA) did not indicate differences between genders. However, another composite score (containing omission errors, commission errors, and response sensitivity) suggested significant improvement only in the boys.


CONCLUSIONS
The results suggested that according to a longitudinal follow-up, behavioral and neuropsychological changes among patients with ADHD might differ between genders. Gathering multidimensional information from patients with ADHD is essential in determining how gender modifies the functional outcome of ADHD.
1 Department of Child and Adolescent Psychiatry, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine , Kaohsiung, Taiwan .
Liang-Jen
LJ
Wang
2 Department of Psychiatry, Chang Gung Memorial Hospital at Keelung , Keelung, Taiwan .|3 Chang Gung University School of Medicine , Taoyuan, Taiwan .
Chih-Ken
CK
Chen
3 Chang Gung University School of Medicine , Taoyuan, Taiwan .|4 Department of Child Psychiatry and Sleep Center, Chang Gung Memorial Hospital at Linko , Taoyuan, Taiwan .
Yu-Shu
YS
Huang
D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy* / Q000503:physiopathology; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use*; D009483:Neuropsychological Tests; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D012737:Sex Factors; D013997:Time Factors
D000697:Central Nervous System Stimulants; D008774:Methylphenidate