Weekend holidays during methylphenidate use in ADHD children: a randomized clinical trial.
OBJECTIVE
The aim of this study was to assess whether weekend drug holidays during methylphenidate (MPH) administration would change the efficacy and tolerability to the medication in male children with Attention-Deficit Hyperactivity Disorder (ADHD).


METHODS
In a 28-day, double-blind study, children with diagnoses of ADHD were randomized to receive BID MPH for 7 days a week (n = 21) or to receive BID MPH on weekdays and a placebo on weekends (n = 19). Parents completed the Conners' Abbreviated Rating Scale (ABRS) to assess ADHD symptoms and the Barkley's Side Effect Rating Scale (SERS) to assess side effects on weekends. Teachers completed the ABRS on each Monday after weekends.


RESULTS
Both groups showed a significant reduction on the ABRS over time as the dose was increased. However, the group difference in the ABRS scores was not statistically significant, either on weekend parent ratings (at the endpoint, p = 0.41; effect size = 0.26) or on teachers' ratings (at the endpoint, p = 0.99; effect size = 0.002). The omission of MPH on weekends was associated with significantly less severity of insomnia (F = 3.96, d.f. = 1, p = 0.05) and a trend for less interference on appetite (F = 3.18, d. f. = 1, p = 0.08).


CONCLUSIONS
Our findings suggest that weekend holidays during MPH administration reduce the side effects of insomnia and appetite suppression without a significant increase in symptoms, either on weekends or in the first school day after them. Possible explanations for these findings (rate-dependent response or impact of demands of the environment) are discussed in this paper.
ADHD Outpatient Clinic, Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, Porto Alegre, Brazil 90035-003.
Sílvia
S
Martins
Silzá
S
Tramontina
Guilherme
G
Polanczyk
Mariana
M
Eizirik
James M
JM
Swanson
Luis A
LA
Rohde
D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000188:drug therapy* / Q000523:psychology; D000697:Central Nervous System Stimulants / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D004311:Double-Blind Method; D001068:Feeding and Eating Disorders / Q000139:chemically induced / Q000453:epidemiology; D006801:Humans; D007361:Intelligence Tests; D008297:Male; D008774:Methylphenidate / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D011569:Psychiatric Status Rating Scales; D007319:Sleep Initiation and Maintenance Disorders / Q000139:chemically induced / Q000453:epidemiology
D000697:Central Nervous System Stimulants; D008774:Methylphenidate