ebook_ADHD2019

The World Federation of ADHD Guide 53 working memory, memory span, processing speed, arousal, temporal informa- tion processing, response variability; and have also impairments in motivational processes. 2,4 However, the findings of neuropsychological impairments are only of moderate effect sizes, not all individuals with the disorder have these dysfunc- tions, and different individuals have a unique profile of such deficits. Coghill et al. 17 evaluated six neuropsychological domains: inhibitory control, memory, delay aversion, decision making, temporal processing and response variability and fou- nd that compared to healthy children ADHD children performed poorly at the group level on all domains. However only 75% of these individuals displayed some deficit, none had a deficit on all domains and only 10% had deficits in 4 or more domains. These results suggest that these domains are relatively independent of each other and support the presence of multiple pathways to ADHD. These fin- dings also support the view that ADHD is a heterogeneous condition at the level of neuropsychological functioning, as well as clinical symptoms and impairments, likely reflecting heterogeneity in the aetiology of ADHD.” THE RELEVANCE OF COMORBIDITIES ADHD is highly comorbid with other psychiatric disorders (70-80% of affected individuals have at least one other disorder). The comorbid profile varies along the lifecycle. 18 The following are among the most common ADHD comorbid con- ditions in children and they should be assessed routinely: oppositional defiant di- sorders (ODD), learning disorders, developmental motor coordination disorder, language disorders, intellectual disabilities, sleep disorders, depressive and anxiety disorders, tic disorders, enuresis, conduct disorder and autism spectrum disorders. Although the exact rate of comorbidity with each one of these diagnoses varies considerably in different studies depending on origin of the sample (e.g., referred or non-referred), a meta-analysis of 21 mixed-gender population studies found that children with ADHD were over 10 times more likely to have CD or ODD, whereas they were over 5 times more likely to have depression and 3 times more likely to have an anxiety disorder compared with peers without ADHD. A meta-a- nalysis assessed comorbidity specifically in female children. Main findings suggest that girls with ADHD frequently exhibit comorbid externalizing and internalizing disorders, as boys. In addition, the pattern of comorbidity did not seem to be very different between girls and boys. 19 In adolescents and adults, other comorbid conditions are also clinically rele- vant, including: eating disorders, substance use disorders (SUDs), bipolar disor- ders, and personality disorders. This comorbidity profile complicates diagnostic assessment and differential diagnosis. 16,20,21 Recent literature has documented that ADHD is also highly comorbid with clinical disorders such as obesity, asthma and atopic conditions, epilepsy, and dia-