This study aims to examine the efficacy of a brain-computer interface system for the treatment of inattentive symptoms of Attention Deficit Hyperactivity Disorder (ADHD). The investigators hypothesis is that children with ADHD receiving treatment with the BCI-based training will improve to a greater extent than the control group.

Additionally, the investigators are also conducting an fMRI study involving interested participants, to elucidate the neural mechanisms underlying any behavioural improvement. This is necessary to help the investigators gain a better picture of brain correlates related to ADHD and understand how the intervention can affect the brain.

This BCI study will involve 2 phases. The first phase is a preliminary study to test the safety and effectiveness of the novel BCI device which involves newly developed dry electrode sensors and intervention game. Twenty children, aged 6-12 and diagnosed with Inattentive or Combined subtype of ADHD will be recruited for the study. This open-label, experimental arm will go through 8 weeks of BCI intervention.

The second phase will be a randomized controlled trial involving 160 children. They will be randomized into the treatment or control arm. The treatment arm will receive 8 weeks of BCI intervention, similar to the experimental arm. The other group will serve as wait-list controls.

The fMRI trial aims to examine the underlying neural processes explaining any therapeutic effects that may be seen.

The study will enroll 70 children with ADHD, aged 6-12, who are participating in the main randomized controlled trial: 40 from the BrainpalTM intervention group and 30 from the control group; participants will undergo fMRI scan at Week 0 and 8 or Week 8 and 16. The study will recruit another 30 children aged 6-12 from the community as the healthy control group, who will undergo the same imaging procedure once. The scans will involve both functional and structural imaging.

Inclusion Criteria:

• DSM-IV-TR criteria for ADHD, either the combined or inattentive subtype, based on the Diagnostic Interview Schedule for Children (CDISC; Schaffer et al., 2000)

Exclusion Criteria:

• Present or history of medical treatment with stimulant medication and Atomoxetine
• Co-morbid severe psychiatric condition or known sensori-neural deficit e.g. complete blindness or deafness (such that they cannot play computer games)
• History of epileptic seizures
• Known Developmental Delay (i.e. IQ 70 and below)
• Predominantly Hyperactive/impulsive subtype of ADHD (i.e. no predominant inattentive symptoms)
• Present/history polyunsaturated fatty acids supplement intake (e.g. Omega-3 oil, flax seed oil, cod liver oil) in the past 3 months
• Present/history of traditional Chinese medicine (TCM) prescribed for treatment of attention problems in the past 1 month