Individualising treatments to help people with poor impulse control

"In my research I use experimental techniques such as genetic analysis, non-invasive brain stimulation, basic biochemistry, computational modelling and non-invasive recording to study impulse control in healthy and clinical human populations", Hayley MacDonald, Associate Professor of Biological Psychology at UiB says, adding:

"So far, my research has focused on the dopamine imbalance seen in Parkinson’s disease, but through collaborations at the University of Bergen I am now starting to extend my focus into other conditions that effect dopamine e.g. attention deficit hyperactivity disorder (ADHD) and Tourette syndrome".

Dopamine imbalances

"I am especially interested in how these measures and underlying mechanisms are influenced by imbalances in the chemical dopamine within the brain. I find this area of research fascinating as the role of dopamine in the brain and body is so complex, and problems with dopamine-related behaviours such as impulse control are seen in such a wide range of neuropsychological conditions", MacDonald says.

Impulse control is the ability to suppress behavioural responses, thoughts, habits, emotions or memories if they are inappropriate, interfering or incorrect for the current environment.

"This ability to control our urges is a vital skill required to function in society, and problems with impulse control can have debilitating consequences for a person, their family and society in general", she explains.

Improving impulse control

"Across the wide range of neuropsychological conditions that involve disturbances in dopamine, medications try to restore functioning levels. It is hoped that rebalancing levels will improve key executive functions - like impulse control - that rely on dopamine and are impaired in these conditions to a debilitating level", MacDonald says.

However, the behavioural response to changes in dopamine through medication is highly variable - and thus unpredictable - within clinical populations. Understanding this variability and predicting responses in individual patients is therefore a critical challenge in neuropsychology. She has now submitted an application to the European Research Council (ERC) for a project aiming to provide a better understanding of the interaction between a person's biology and their psychological characteristics - and open the door to tailored medication and treatment in the future.

"My career goal is to help guide clinical practice for people with these dopamine-related conditions by helping to individualise treatments and interventions", she says. 

"My aim is to do this through the knowledge gained from my translational research approach spanning basic biochemistry and genetics, through to neurophysiology in healthy humans, and finally clinical populations".

Extending the research focus

For her PhD at the University of Auckland, MacDonald was studying the brain mechanisms underlying our impulse control. This is where her interest in this research area was sparked. With funding from the Neurological Foundation of New Zealand, she later moved to the University of Birmingham doing research for her postdoctoral fellowship.

Today, at the Department of Biological and Medical Psychology at The University of Bergen, MacDonald is involved in research and teaching in the field of Biological Psychology, and her expertise also overlaps into Cognitive Neuroscience.

She is the coordinator for a Biological Psychology course taken by the professional psychology students and head of the Bergen Dopamine Group, a research group within the department which is affiliated with the Bergen fMRI Group.