Klorman 1990.

Study characteristics
Methods	Cross‐over trial with 2 interventions: MPH placebo Phases: 2
Participants	Number of participants screened: not clear Number of participants included: 48. (42 boys, 6 girls) Number of participants followed up: appears to have been 48 Number of withdrawals: not clear Diagnosis of ADHD: DSM‐III Age: mean not stated (range 12‐18 years) IQ: mean 108.62 MPH‐naive: 46/48; 2 had brief trials in childhood Ethnicity: white (46) Country: USA Setting: outpatient clinic Comorbidity: oppositional and CD (24), oppositional not CD (12), anxiety (5), drug or alcohol abuse (2), depression (1) Comedication: no Other sociodemographics: double‐ or single‐parent family, predominantly middle class (mean Hollingshead socioeconomic status score of 48.8 (i.e. social class II)) Inclusion criteria Participants 12‐18 years of age without previous stimulant therapy referred for evaluation of response to stimulants from 1984‐1988 Exclusion criteria CNS involvement Childhood autism Psychosis Uncorrected visual or auditory problems IQ < 80
Interventions	Participants were randomly assigned to 3 weeks of MPH and placebo Mean MPH dosage: 35.21 mg (± 5.94 (SD)). Range 15 mg (2 daily doses) to 40 mg (3 daily doses) Administration schedule: doses were gradually increased at the end of the 1st and 2nd weeks Washout before trial initiation: not described Titration period: after randomisation Treatment compliance: not stated
Outcomes	ADHD symptoms Abbreviated Conners' Hyperactivity Questionnaire: rated by teacher and parent, weekly IOWA Inattention/Overactivity and Aggression Scales: rated by teacher and parent, weekly Mean parent‐ and teacher‐reported Conners' hyperactivity and inattention scores were graphed but SD values were not. Also, the paper did not refer to measures of impulsivity or total scores. We could not use these data in our meta‐analyses because values were missing and trial authors were not able to provide supplemental data on this outcome Non‐serious AEs Side effects reported in Table 4: appetite loss; increased thirst, dry mouth, stomachaches, nausea, headaches, sleep problems, shakiness, crying, anger, unhappiness, sadness
Notes	Sample calculation: not described Ethics approval: not described Key conclusion of trial authors These results support the continued effectiveness of stimulant therapy for attention deficit disorder in adolescence. However, the magnitude of clinical effectiveness reported was smaller than was previously found in younger patients Exclusion of MPH non‐responders/children who have previously experienced AEs while taking MPH before randomisation: no Any withdrawals due to averse events: Unclear, none mentioned Funding source: National Institute of Mental Health (NIMH) grant MH38118 Email correspondence with trial authors: April 2014. We obtained supplemental information/data from trial authors (Magnusson 2014a [pers comm])
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Received information from trial author (Magnusson 2014a [pers comm])
Allocation concealment (selection bias)	Low risk	Received information from trial author (Magnusson 2014a [pers comm])
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"Substances were dispensed in capsules of identical appearance" (p 703)
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Parent and teacher ratings were used and participants were blinded to which capsule they were receiving
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not stated Selection bias (e.g. titration after randomisation → exclusion): no
Selective reporting (reporting bias)	Unclear risk	No protocol identified