Summary of findings for the main comparison. Cognitive‐behavioural interventions versus unspecific control for attention deficit hyperactivity disorder (ADHD) in adults.

Cognitive‐behavioural interventions versus unspecific control for ADHD in adults
Patient or population: adults with ADHD Setting: ambulatory/hospital (outpatients) Intervention: CBT Comparison: control
Outcomes	Anticipated absolute effects* (95% CI)		Relative effect (95% CI)	№ of participants (studies)	Quality of the evidence (GRADE)	Comments
	Risk with control conditions	Risk with CBT
CBT versus supportive therapy
ADHD symptoms: observer‐rated Assessed by: various scales Follow‐up: 12 weeks	—	The mean ADHD observer‐rated symptoms score in the intervention groups was 0.56 standardised deviations lower (1.01 lower to 0.12 lower)	—	81 (1 RCT)	⊕⊕⊝⊝ Lowa	Moderate effect sizeb
ADHD symptoms: self‐reported Assessed by: various scales Follow‐up: 12 to 14 weeks	—	The mean ADHD self‐rated symptoms score in the intervention groups was 0.16 standardised deviations lower (0.52 lower to 0.19 higher)	—	122 (2 RCTs)	⊕⊕⊝⊝ Lowc	Small effect sizeb
CBT versus waiting list control
ADHD symptoms: observer‐rated Assessed by: various scales Follow‐up: 8 to 12 weeks	‐	The mean ADHD self‐rated symptoms score in the intervention groups was 1.22 standardised deviations lower (2.03 lower to 0.41 lower)	—	126 (2 RCTs)	⊕⊝⊝⊝ Very lowd	Large effect sizeb
ADHD symptoms: self‐reported Assessed by: various scales Follow‐up: 8 to 12 weeks	—	The mean ADHD self‐rated symptoms score in the intervention groups was 0.84 standardised deviations lower (1.18 lower to 0.50 lower)	—	251 (5 RCTs)	⊕⊕⊕⊝ Moderatee	Large effect sizeb
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). ADHD: attention deficit hyperactivity disorder; CBT: cognitive‐behavioural therapy;CI: confidence interval.
GRADE Working Group grades of evidence High quality: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate quality: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low quality: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low quality: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.

^a We downgraded the quality of evidence due to imprecision (considering the width of the CI), methodological limitations (due to high risk of bias in blinding of participants and personnel), and because the evidence is based on a single study.
 ^bTo assess the magnitude of effect for continuous outcomes, we used the criteria suggested by Cohen 1988: 0.2 represents a small effect, 0.5 a moderate effect, and 0.8 a large effect.
 ^cWe downgraded the quality of evidence due to imprecision (considering the width of the CI) and methodological limitations (due to high risk of bias in blinding of participants and personnel and five other domains with unclear risk of bias).
 ^d We downgraded the quality of evidence due to imprecision (considering the width of the CI), methodological limitations (due to high risk of bias in blinding of participants and personnel and three other domains with unclear risk of bias) and inconsistency (considering the I² of 74%). The estimates of each study was: Hepark 2015 SMD −0.85 lower (−1.30 lower to −0.40 lower) and Stevenson 2002 SMD −1.68 lower (−2.39 lower to −0.98 lower).
 ^e We downgraded the quality of evidence due to methodological limitations (considering that two out of the five studies were at high risk of bias in more than one domain other than blinding of participants and personnel).