Mayes 1994.

Methods	A cohort study of 69 children with attention deficit hyperactivity disorder (ADHD) who underwent blind methylphenidate trials
Participants	Number of participants screened: not stated Number of participants included: not stated Number of participants followed up: 69 Number of withdrawals: not stated Diagnosis of ADHD: DSM‐IIIR (subtype: hyperactive‐impulsive (100%)) Age: mean 7.1 years old, range 22 months‐13 years IQ: mean 86, range 23‐136 Sex: not stated Methylphenidate‐naïve: not stated Ethnicity: not stated Country: USA Comorbidity: 36 had ADHD alone (with or without a learning disability) and 33 had additional neurodevelopmental disorders Comedication: not stated Sociodemographics: not stated Exclusion criteria Children with ADHD but not hyperactivity
Interventions	MPH was prescribed three times daily (8 am, noon, 4 pm) with a starting dose of 0.3 mg/kg rounded to the nearest 2.5 mg. MPH was trialled using an ABA design (A = no medication, B = MPH). Days per MPH dosage was a minimum 3 days (mean of 6 days) and no medication minimum of 6 days (mean 11 days). MPH was increased by 2.5 mg or 5 mg per dose until a response was achieved. The total mean days per MPH dosage was 8 days, mean days no medication 9 days. Doses for responders 50/69 ranged from a dosage of 2.5 mg to 10 mg. The dosage given to the 19/69 who did not respond or did not complete the trial (6/69) were not reported
Outcomes	Non‐serious adverse events An adverse event was defined as being reported on ≥ 2 methylphenidate days (i.e. at the response dosage for responders or at the highest dosage for non‐responders) and not reported on ≥ 2 methylphenidate‐free days
Notes	Sample calculation: not stated Ethics approval: not stated Funding/vested interests: not stated Key conclusions of the study authors: the results confirm and add to the research literature indicating that ADHD children who are of preschool age and/or who have co‐existing neurological disorders may benefit from methylphenidate Exclusion of methylphenidate non‐responders/children who have previously experienced adverse events on methylphenidate: no Supplemental information has not been able to retrieve from authors due to lack of email address