Brain network malleability by computerised cognitive training in attention deficit hyperactivity disorder

INTERVENTION: After a pretest including neuropsychological assignment, cognitive tasks, and magnetic resonance imaging, the participants were assigned to an experimental group (performing dual n‐back working memory task) or an active control group (playing Bejeweled 2 computer game) with simple randomisation using an equal amount of lottery tickets per group. Each participant in both groups trained for 5 weeks, three times a week, 25 minutes at a time, adding up to total of 15 training sessions. A post‐test with the same elements as the pretest was conducted after the cognitive training. The participants were blind to whether they belonged to the experimental or the control group, as was the experimenter conducting the pre‐ and post‐tests. CONDITION: Attention deficit hyperactivity disorder ; Mental and Behavioural Disorders PRIMARY OUTCOME: Blood oxygen level dependent (BOLD) signal in the brain measured by functional magnetic resonance imaging during the pretest (within few weeks before the cognitive training) and the posttest (within few weeks after the cognitive training). Due to the study’s experimental design, BOLD signal is assessed in different conditions (during working memory task, rest, and movie watching) and can be analysed in several ways, including regional activity and their temporal correlations. SECONDARY OUTCOME: White matter properties of the brain measured by diffusion‐weighted magnetic resonance imaging during the pretest (within a few weeks before the cognitive training) and the posttest (within a few weeks after the cognitive training). White matter properties can be analysed in several ways, including microstructure and tractography. INCLUSION CRITERIA: 1. Age between 18 and 63 years 2. Diagnosed with attention deficit hyperactivity disorder according to DSM‐IV by a specialised doctor 3. Excellent competency in Finnish 4. Sufficient vision and hearing