Title: Investigating the effects of cardio and non-cardio exercise on adults
with Attention Deficit Hyperactivity Disorder (ADHD)
Funding body: Rosetrees Trust Seedcorn Award
Funding Awarded: £59,282
PI: Dr. Eleanor Dommett (Kings)
CIs: Dr Nicola Byrom (Kings), Dr Bryan Singer., (Sussex), Professor Paul Overton Sheffield).
Attention Deficit Hyperactivity Disorder (ADHD) is characterised by poor attention, heightened impulsivity and hyperactivity. Consequences of the disorder include higher risk of other psychiatric and physical health conditions and poorer academic and occupational functioning. Although often considered a childhood disorder, it affects 3% of adults and, critically, these adults are a separate group to the children with ADHD i.e. adults with ADHD are not simply children with ADHD who grew up. This means that research findings from children with ADHD may not apply to adults with the condition.
Irrespective of age, ADHD is typically treated with psychostimulants (e.g. amphetamine) which are effective in over 80% of patients. Exactly how they work is unclear, but it is believed that their ability to increase the brain chemical dopamine is key to their success. However, whilst psychostimulants reduce symptoms, they have side effects ranging from insomnia to tachycardia and psychosis and there are concerns about the drugs being abused - 50% of adults prescribed psychostimulants give away or sell their medication and a further 30% misuse it themselves. It is therefore important that other treatments are explored. Preliminary research has suggested that exercise may be a safe and effective treatment for ADHD. However, to date studies investigating this have been limited by small sample sizes, a lack of proper experimental controls and they have neglected the adult population with the condition.
This project aims to fully investigate the impact of exercise on core symptoms and related behaviour in adults with ADHD using a robust experimental paradigm. We will examine the impact of two different types of exercise: cardio (cycling) and non-cardio (yoga). Both types have been shown to have positive effects in children with ADHD and animal research indicates that cardio exercise can increase dopamine the brain, much like psychostimulant drugs. The effect of exercise on the three core symptoms will be assessed using established reliable tests of (Test of Visual Attention), impulsivity (Iowa Gambling Task, Delayed Discounting Task) and hyperactivity (actiograph movement measurement). Additionally, we will measure reward-learning, something which is found to be impaired in ADHD, is linked to dopamine signalling and thought to underpin the core symptoms. Critically, we will conduct the study in three groups: Healthy Control participants, Adults with ADHD not currently taking psychostimulants and Adults with ADHD currently taking psychostimulants. By using this approach, we will be able to establish whether exercise can normalise the key measures in those with ADHD by itself or only as an adjunct to psychostimulant treatment. Either effect of exercise could offer some benefit to patients because, even as an adjunct, it could allow a reduction in the dose of psychostimulant required and therefore the level of side effects and abuse risk.