A collaborative study between U.K. and Italian researchers has provided new insights into the biological mechanisms behind major depressive disorder (MDD), particularly the role of the immune system. Published in *Molecular Psychiatry*, the study focused on “gene expression”—the process through which the instructions encoded in our genes influence bodily functions.
About one in three individuals with depression experience elevated inflammation, an immune system response typically activated during stress. This inflammation may explain why some people with depression do not respond to standard antidepressants and could benefit from treatments targeting the immune system, such as anti-inflammatories. Understanding the biological processes driving this inflammation could offer new approaches to treating depression, especially in those who are resistant to conventional treatments.
“In depression, like many other medical conditions, a single treatment approach doesn’t work for everyone. To provide better care, we must recognize the different biological patterns at play,” said Dr. Luca Sforzini from King’s IoPPN.
Using mRNA sequencing technology, researchers measured gene activity in the blood of individuals with depression. They found that people with elevated inflammation exhibited increased gene activity related to the immune system and metabolic processes, such as energy production and regulation of fats and sugars. Even moderate levels of inflammation triggered significant immune-related gene activity, while those with higher inflammation showed additional activation of genes involved in metabolism.
Professor Annamaria Cattaneo explained that gene expression may reveal underlying biological factors that aren’t immediately visible, offering a bridge between genetic encoding and observable symptoms. This research could help deepen our understanding of depression’s biological underpinnings.
As reported by medicalxpress, the study also identified a distinct gene expression profile in individuals who responded well to antidepressants. These changes involved not only immune system inhibition but also brain protection, indicating that these processes may be crucial to recovery and the effectiveness of antidepressants
Overall, the research emphasizes the importance of gene expression in understanding depression and how antidepressants work. Biological patterns tied to our genes could explain why some people with depression respond to treatment differently, or why some develop related medical conditions like diabetes and cardiovascular disease.
“Our findings underline the need to move beyond traditional approaches and adopt more personalized treatment strategies based on the biological roots of different types of depression,” said Professor Carmine Pariante.