WORDS DR HIRAN SHANAKE PERERA
 FEATURED EXPERTDR HIRAN SHANAKE PERERA Cognitive Neuroscientist and Senior Lecturer School of Arts and Liberal Sciences Faculty of Social Sciences & Leisure Management Taylor’s University |
Imagine waking up every day and:
- Feeling persistently low
- Unable to find joy in activities (anhedonia)
- Struggling with impaired social interactions
- Experiencing memory failures when you need them most
These are just some of the symptoms of depression, a condition that profoundly impacts personal, social, and occupational life.
MAJOR DEPRESSIVE DISORDER IS A LEADING GLOBAL BURDEN OF DISEASE
According to the World Health Organization (WHO), major depressive disorder (MDD) ranks as a leading global burden of disease.
MDD affects nearly 5% of the world’s population and stands as one of the top causes of global disability.
Alarmingly, the prevalence of depression among adolescents and young adults is rising, highlighting the growing reliance on long-term medications to manage its symptoms.
When addressing mental health disorders, it is essential to focus on the brain, the organ of the mind. The challenge lies not just in seeking professional help but in achieving accurate diagnoses.
THE ROLE OF NEUROIMAGING IN UNDERSTANDING DEPRESSION
Currently, mental health practitioners rely on assessments and clinical judgments to diagnose disorders.
Unlike physical ailments where organs can be directly examined, it is often more challenging to directly assess the brain.
However, technological advancements in neuroimaging are bridging this gap, offering valuable insights into depression and other mental health conditions.
| Neuroimaging is a procedure comparable to taking pictures of the brain to understand how it looks and works. It uses advanced tools like MRI (magnetic resonance imaging) and EEG (electroencephalography) to show how different parts of the brain are structured and how they communicate with each other. These methods help scientists and doctors study the brain and its activity, to obtain information that is especially useful to understand conditions such as depression. |
HOW NEUROIMAGING WORKS
Two prominent non-invasive neuroimaging methods are:
- Magnetic resonance imaging (MRI) which includes both structural and functional MRI to study brain anatomy and activity.
- Electroencephalography (EEG), which measures electrical activity in the brain through electrodes placed on the scalp.
These tools have unveiled patterns of brain activity and structural changes in regions associated with mood regulation, such as the amygdala and prefrontal cortex.
WHAT NEUROIMAGING HAS SO FAR TAUGHT US ABOUT DEPRESSION
Structural MRI Insights
- In people with depression, the brain’s grey matter, which helps process information, is thinner than usual.
- The hippocampus, a part of the brain important for memory, is smaller, which could be the reason why the affected person has memory problems.
Functional MRI Insights
- The amygdala, the brain’s center for processing emotions, becomes more active when people with depression see emotional facial expressions.
- The dorsolateral prefrontal cortex, which helps with decision-making and planning, shows less activity.
EEG Insights
Higher levels of alpha brainwaves during sleep are associated with suicidal thoughts.
Differences in alpha activity between the left and right sides of the brain (alpha asymmetry) reveal distinct tendencies:
- The left hemisphere is linked to behaviors where a person moves toward goals or rewards.
- The right hemisphere is connected to withdrawal or avoidance behaviors.
People with depression often show increased alpha activity in the left hemisphere, which may indicate lower motivation to pursue goals.
HOWEVER, THERE ARE CHALLENGES IN INCREASING THE ADOPTION OF NEUROIMAGING TO STUDY AND DIAGNOSE DEPRESSION
Despite its promise, neuroimaging faces significant barriers.
- Cost. Sophisticated neuroimaging equipment is expensive to purchase and maintain, which limits their accessibility.
- Complexity. Interpreting brain scans requires specialized expertise, thus increasing the risk of misdiagnoses without the involving trained personnel.
- Ethical concerns. Privacy issues and potential misuse of sensitive brain data necessitate strict compliance with ethical guidelines and regulations.
Some possible means to overcome these challenges include:
- Continued technological innovation to make tools more affordable and accessible.
- Academic and clinical collaboration, through prioritizing funding for neuroimaging research and building partnerships between academic institutions and healthcare sectors to translate findings into clinical practice.
WHAT LIES IN THE FUTURE FOR NEUROIMAGING?
Neuroimaging has deepened our understanding of depression by exploring biomarkers—measurable indicators of biological processes—linked to this condition.
These advancements hold the potential to revolutionize the monitoring, diagnosis, and treatment of depression.
Hence, I am optimistic that neuroimaging can and will complement existing diagnostic methods, offering a more comprehensive understanding of depression. This integration can pave the way for tailored and effective treatment strategies.
