Working memory and set-shifting in school-aged children classified as having attention-deficit hyperactivity disorder

BACKGROUND: Attention-deficit hyperactivity disorder (ADHD) is a common psychiatric disorder reported in both children and adults; it is often associated with a variety of executive functioning deficits. AIM: This study investigated the extent to which working memory and set-shifting are impaired in school children with and without ADHD. SETTING: This included primary schools in Lepelle-Nkumpi Municipality in Limpopo province, South Africa. METHODS: A total of 216 children (108 screened positive for ADHD and 108 matched controls without ADHD symptoms), aged between 6 and 15 years, participated in the study. The performance of the two groups was compared on tests of working memory (Forward and Backward Digit Span subtests of the Wechsler Intelligence Scale for Children - Fourth Edition) and set-shifting (Trail Making Test Part B). The scores were analysed as a function of gender and age. RESULTS: The group with possible ADHD performed worse than the neurotypical control group on tasks of working memory and set-shifting. The results did not indicate that gender affected performance. However, the younger age group performed worse than the older children. CONCLUSION: Children classified as ADHD showed significantly more impairments in working memory and set-shifting than neurotypical controls. Neither test showed any significant difference between male and female performance, whilst age was shown to affect performance on both tests. Early identification and treatment of children with attention-deficit hyperactivity disorder are crucial to their well-being.