Shiels 2009.

Study characteristics
Methods	3‐day, double‐blind, placebo‐controlled cross‐over trial with 3 arms: LD‐MPH HD‐MPH placebo
Participants	Number of participants screened: not stated Number of participants included: 49 (80% boys, 20% girls) Number of participants followed up: not stated Number of withdrawals: 0 Diagnosis of ADHD: DSM‐IV (combined 35 (71%), hyperactive‐impulsive 3 (6%), inattentive 11 (23%)) Age: mean 10.5 years (range 9‐12) IQ: mean 104 (range not stated) MPH‐naive: not stated Ethnicity: white (76%), African American (14%), other (10%) Country: USA Setting: outpatient clinic (summer research programme) Comorbidity: ODD (43%), CD (22%) Comedication: not stated Other sociodemographics: none Inclusion criteria DSM‐IV ADHD diagnosis Attending ADHD summer research programme Exclusion criteria Full‐scale IQ < 80 History of seizures or other neurological problems or medication to prevent seizures History of other medical problems for which psychostimulant treatment may involve considerable risk Current use of psychotropic medications other than for ADHD (i.e. antipsychotics, mood stabilisers, antidepressants and anxiolytics) History or concurrent diagnosis of pervasive developmental disorder, schizophrenia or other psychotic disorders Absence of functional impairment Vision or hearing problems that would make it difficult to complete discounting tasks (or other tasks; data not reported)
Interventions	Participants were assigned to extended‐release MPH in "high" or "low" dose (range 18‐90 mg/d) No of participants randomised: not stated Mean MPH: LD 39 mg (Concerta), HD 73 mg (Concerta) Administration schedule: once daily Time points: in the morning, 90 min before cognitive task Duration of intervention: 7:30 am‐5:00 pm, Monday through Thursday Titration period: not stated Treatment compliance: not stated Washout before trial initiation: MPH 1 week if taking atomoxetine, 24 h if taking MPH
Outcomes	General behaviour Impairment Rating Scale (IRS; Fabiano 2006) Non‐serious AEs Pittsburgh Side Effects Rating Scale, BP and heart rate assessed daily during times of peak medication effects
Notes	Sample calculation: not stated Ethics approval: not stated Key conclusions of trial authors These findings provide initial evidence that stimulant medication reduces delayed discounting among those with the disorder MPH, an effective pharmacological treatment for ADHD, reduced the preference for smaller immediate rewards over larger delayed rewards when delays and rewards were actually experienced by the child. This raises the possibility that stimulant medication improves real‐world behaviour of children with ADHD by altering delay‐related impulsivity Comment from review authors This study focused on effects of MPH on "delay discounting", a function of impulsivity. However, no data are available on the effects of MPH on ADHD symptoms more generally, nor are data available regarding side effects or changes in blood pressure and pulse. Exclusion of MPH non‐responders/children who have previously experienced AEs while taking MPH before randomisation: no Any withdrawals due to AEs: none Funding source: National Institute of Mental Health Email correspondence with trial authors: July 2014. Emailed trial authors to request additional information but have not received a response
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"To maintain blinding, participants were given the same number of opaque capsules per day regardless of actual MPH dose"
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information
Incomplete outcome data (attrition bias) All outcomes	Low risk	No withdrawals Selection bias (e.g. titration after randomisation → exclusion): no
Selective reporting (reporting bias)	Unclear risk	No protocol identified