Bouffard 2003.

Study characteristics
Methods	Design: Double‐blind, cross‐over trial of placebo versus IR methylphenidate Unit of randomization: individual
Participants	Location/Setting: not reported Sample size: 38 Number of withdrawals/dropouts: 8 Sex (with 8 withdrawals/dropouts excluded; n = 30): 24 male and 6 female participants Mean age: 34 years Inclusion criteria: DSM‐IV criteria for ADHD Score of 1.5 or more on at least 1 ADHD self‐report questionnaire (either Conners’ Adult ADHD Rating Scale or the Adult ADHD Problem Behaviours scale) Estimated IQ of 80 or above on abbreviated Wechsler Adult Intelligence Scale ‐ Revised Exclusion criteria: Psychiatric conditions that better accounted for their current symptoms or required other treatment Substance abuse in the preceding 6 months Medical condition contra‐indicating stimulants (i.e. hypertension or cardiac disease)
Interventions	Intervention (n = 38): IR methylphenidate Control (n = 38): placebo Administration: comparison of 2 dosages of IR methylphenidate (10 mg 3 times daily and 15 mg 3 times daily) to each other and to equivalent dosages of placebo. Each dosage was given for 2 weeks. Participants were randomly assigned to start either IR methylphenidate or placebo. Medication was started with a 3‐day lead‐in of increasing dosages, as follows: day 1, 5 mg 3 times daily; day 2, 10 mg 3 times daily; day 3, 15 mg 3 times daily
Outcomes	Primary outcomes: Changes in ADHD symptoms, assessed using the self‐report questionnaires Conners’ Adult ADHD Rating Scale and the Adult ADHD Problem Behaviours Scale Objective measures of attention and response inhibition, assessed using the computerized Continuous Performance Test (CPT) and stop‐signal task Secondary outcomes: Changes in other symptoms, assessed using the Symptom Checklist‐90‐Revised (SCL‐90‐R), Hamilton Anxiety Rating Scale (HARS) and Beck Depression Inventory (BDI) Timing of outcome assessment: 2 weeks
Notes	Study start date: not reported Study end date: not reported Funding source: This research was supported by an Fonds de la Recherche en Santé du Québec (FRSQ) grant for the study of adults with ADHD Conflicts of interest: none disclosed
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "We gave the hospital pharmacy a numbered list indicating a randomly chosen (from a hat) order of medication to start first (either methylphenidate or placebo) and assigned each subject a number. Subjects gave their number to the pharmacist when picking up their prescriptions."
Allocation concealment (selection bias)	Unclear risk	Comment: Insufficient information available to permit a judgment.
Blinding of participants (performance bias)	Unclear risk	Comment: Insufficient information available to permit a judgment.
Blinding of personnel (performance bias)	Unclear risk	Comment: Insufficient information available to permit a judgment.
Blinding of outcome assessment (detection bias) Efficacy, Symptoms of ADHD	Unclear risk	Comment: The questionnaires were self‐reported but it is unclear whether masking of the participant was guaranteed
Blinding of outcome assessment (detection bias) Harms	Unclear risk	Comment: The questionnaires were self‐reported but it is unclear whether masking of the participant was guaranteed
Incomplete outcome data (attrition bias) Efficacy, Symptoms of ADHD	Unclear risk	Comment: The flow of participants randomized and enrolled was not reported
Selective outcome reporting Efficacy, Symptoms of ADHD	High risk	Comment: Outcomes of interest were reported incompletely
Selective outcome reporting Harms	High risk	Comment: Outcome measurement was self‐reported; it could differ between intervention groups and likely be influenced by knowledge of the intervention received