Measurement of health-related quality of life (HRQOL) in
attention-deficit-hyperactivity disorder (
ADHD) gives a more complete picture of day-to-day functioning and treatment effects than behavioural rating alone. The aim of this pilot study was to investigate the impact of the combined diagnoses of
developmental coordination disorder (
DCD) and
ADHD on HRQOL, and the effectiveness of
methylphenidate (MPH) on HRQOL. HRQOL was established using the Dutch-Child-AZL-TNO-Quality-of-Life (DUX-25) and the TNO-AZL-Child-Quality-of-Life (TACQOL) questionnaires, completed by children and parents. HRQOL of these children was compared with that of 23 age- and sex-matched healthy controls. Twenty-three children (21 males, two females; mean age 8 y 6 mo, [SD 3 mo] range 7 y-10 y 8 mo) with
ADHD/
DCD entered a 4-week, open-label MPH study, after MPH-sensitivity was established, in a double-blind, placebo-controlled trial. In these children's self- and proxy reports, impact of both
DCD and
ADHD was reflected in lower general well-being (self and proxy report p=0.001) due to lower functioning in motor (selfp=0.026; proxy 0.001), autonomic (self p<0.001; proxy p=0.047), cognitive (self p=0.001; proxy p=0.01), and social (self and proxy p<0.001) domains. HRQOL scores improved in 18 children receiving MPH (p=0.001) versus controls. The
ADHD /
DCD group also demonstrated a significant improvement in
ADHD symptoms (p<0.001) and motor functioning (p<0.001). Additional motor
therapy will still be needed in about half of the children with
ADHD/
DCD receiving MPH, within
multimodal treatment including educational and psychosocial assistance.