The primary objective of this study was to examine the effects of the Cogmed training program on working memory among youths 7 to 13 years old, while controlling presence and presentation of ADHD-related comorbidity. A secondary objective was to examine the generalization of effects to ADHD symptoms, non-verbal reasoning, attentional and executive functions, motor impulsivity, reading comprehension, and mathematical reasoning. Participants were under pharmacological treatment for ADHD combined type and a comorbidity. They were randomized into an experimental group that received the Cogmed program and an active control group that received a low-intensity comparison version of the training. They were evaluated at three time points: six weeks prior to intervention onset (T1), immediately prior to onset(T2), and one week following intervention completion (T3).

Participants completed the Cogmed WM training program at home.Each training session lasted from 30 to 45 minutes and was supervised by a parent. For five consecutive weeks, participants had to complete at least five sessions per week.

Inclusion Criteria:

• (1) be 7 to 13 years old;(2) had to be diagnosed with ADHD combined type and present a comorbid learning disability, oppositional defiant disorder or Tourette syndrome;and (3) had to be medicated for ADHD,

Exclusion Criteria:

• Youths were excluded from the study if diagnosed with epilepsy, an internalizing disorder (anxiety or mood disorder), an autism-spectrum disorder or mental retardation.

Double-blind evaluation Participant and assessor are blind