WM is commonly impaired in individuals with ADHD • It is estimated that 81% of children with ADHD have deficits in the “working” component of WM (e.g. the attentional control center or central executive) (Rapport et al., 2013). • WM functioning is dependent on dopamine (Williams & Goldman-Rakic, 1995), which is consistent with the association of ADHD with atypical dopaminergic transmission (Cook et al., 1995). Groups with ADHD have demonstrated gains in WM capacity post Cogmed training • Over 30% of the peer-reviewed, published Cogmed research focuses on children and adolescents with ADHD. • 14 out of 15 papers reveal that participants with ADHD improve after Cogmed training on measures of WM not previously practiced.		Claims and Evidence
			To read about all of the claims that Cogmed makes and the research and clinical evidence supporting those claims, please read the Cogmed Claims and Evidence 3.0 document.

Improvements in symptoms of inattention have been shown after Cogmed training in groups with ADHD and other clinical diagnoses using behavioral rating scales (e.g. the inattention subscale from DSM-IV)

• The effect of training has been observed on improved parental ratings of inattention in ADHD children both immediately post Cogmed and at follow-up three months later (Klingberg et al., 2005).
• Data from 769 children collected pre and post-Cogmed at three distinct practices in Singapore, the Netherlands, and Canada has revealed that on average, Cogmed End-Users improved their inattentive symptoms, as rated on the DSM-IV Parent Rating Scale, by 30% from baseline to post-test. (Clinical Evaluation Series Part I).

• Children, mostly with ADHD, improved on the Inattention score of the Disruptie Behaviors Rating Scale by 33% at post-test, 42% at 6 months, and 40% at 12 months post-training. (Clinical Evaluation Series Part II).

To read about all of the claims that Cogmed makes and the research and clinical evidence supporting those claims, please read the Cogmed Claims and Evidence 3.0 document.

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Below are a sample of published studies that are especially relevant in demonstrating the relationship between working memory and ADHD. All of the studies have been published in top quality scientific journals.

Note that these studies do not examine the efficacy of Cogmed Working Memory Training – review Cogmed’s studies here.
You can also read an explanation by Prof. Torkel Klingberg about Cogmed’s research.

Year	Publication	Title	Author	Abstract
2010	Journal of Abnormal Child Psychology	Working memory demands impair skill acquisition in children with ADHD.	Huang-Pollock et al.	Link to abstract
2010	Journal of Abnormal Child Psychology	ADHD and working memory: The impact of central executive deficits and exceeding storage/rehearsal capacity on observed inattentive behavior.	Kofler et al.	Link to abstract
2010	Journal of Abnormal Child Psychology	Competing core processes in attention-deficit/hyperactivity disorder (ADHD): Do working memory deficiencies underlie behavioral inhibition deficits?	Alderson et al.	Link to abstract
2009	Journal of Abnormal Child Psychology	Hyperactivity in boys with attention-deficit/hyperactivity disorder (ADHD): A ubiquitous core symptom or manifestation of working memory deficits?	Rapport et al.	Link to abstract
2008	Journal of Abnormal Psychology	Cognitive inhibition and working memory in attention-deficit/hyperactivity disorder.	Engelhardt et al.	Link to abstract
2005	Journal of the American Academy of Child and Adolescent Psychiatry	A meta-analysis of working memory impairments in children with attention-deficit/hyperactivity disorder.	Martinussen et al.	Link to abstract
2002	Nature Neuroscience	Neuroscience of attention-deficit/hyperactivity disorder: the search for endophenotypes	Castellanos et al.	Link to abstract
1997	Psychological Bulletin	Behavioral inhibition, sustained attention, and executive functions: Constructing a unifying theory of ADHD.	Barkley	Link to abstract