New research by King’s College London‘s Institute of Psychiatry, Psychology & Neuroscience (IoPPN) reveals that depression and the risk of depression are connected to distinct inflammatory proteins in boys and girls. When the body experiences inflammation, it releases proteins known as cytokines into the blood. While previous studies have linked higher cytokine levels to depression in adults, there is limited knowledge about this connection in adolescents.
The study, published in the Journal of Affective Disorders, explores the differences between boys and girls in how inflammatory proteins relate to depression. It found that specific cytokines played a role in depression risk and severity, but these differed between both the gender. This research was supported by the IDEA (Identifying Depression Early in Adolescence) project, funded by MQ Mental Health Research.
In this study, researchers checked for inflammation by examining blood proteins called cytokines in 75 teenage boys and 75 teenage girls aged 14-16 from Brazil. They divided these 150 participants into three groups, each with 50 people (25 girls and 25 boys): one group had a low risk of depression and wasn’t depressed, and another had a high risk of depression. However, it wasn’t depressed; the last group had major depressive disorder (MDD).
The results showed differences between both the genders in the specific inflammatory proteins related to teenage depression. In boys, having higher levels of a cytokine called interleukin-2 (IL-2) was linked to a higher risk of depression and more severe depressive symptoms.
However, this wasn’t the case for girls. On the other hand, higher levels of another cytokine called IL-6 were associated with more severe depression in girls but not in boys. In boys, the levels of IL-2 were highest in the group at increased risk for depression and even higher in the group with depression, suggesting that in boys, IL-2 levels in the blood could indicate the possibility of future depression.
Dr. Zuzanna Zajkowska, Postdoctoral Researcher at King’s IoPPN and first author of the study, said, “This is the first study to show differences between boys and girls in the patterns of inflammation that are linked to the risk and development of adolescent depression. We found that the severity of depressive symptoms was associated with increased levels of the cytokine interleukin-2 in boys but interleukin-6 in girls. We know more adolescent girls develop depression than boys and that the disorder takes a different course depending on sex, so we hope our findings will enable us to understand better why these differences exist and ultimately help develop more targeted treatments for different biological sexes.”
Researchers in Brazil worked with teenagers from public schools. They used a unique score to figure out how likely these teens were to experience depression based on different factors like their background. The teenagers answered questions about their feelings, relationships, experiences, and moods. They also had a check-up with a child and adolescent psychiatrist.
The study found that inflammation in the body, combined with a person’s gender, could play a role in the risk of developing depression. Adolescence is a crucial time for mental health, and understanding which inflammation markers are connected to depression and how this differs between boys and girls can help us better grasp what’s happening during this vital stage of life. This research reminds us that we need to look at a person’s biology, emotions, and social factors together to understand why depression happens genuinely.
Professor Valeria Mondelli, a Clinical Professor of Psychoneuroimmunology at King’s College London, led this study. She’s also in charge of the Psychosis and Mood Disorders team at the NIHR Maudsley Biomedical Research Centre (BRC). This study is part of the Identifying Depression Early in Adolescence (IDEA) project, which Professor Mondelli is leading and is supported by MQ Mental Health Research.
The IDEA project studies how different factors such as culture, society, genes, and the environment contribute to depression in various countries in young people aged 10 to 24.
This study helps to find unique signs related to inflammation in both the genders that can show if they might have depression. Knowing these signs can lead to better ways to find and help teenagers with depression early on. This will make it easier to care for their mental health and make them feel better.
Journal Reference:
- Zuzanna Zajkowska, Naghmeh Nikkheslat, et al., Sex-specific inflammatory markers of risk and presence of depression in adolescents. Journal of Affective Disorders. DOI: 10.1016/j.jad.2023.07.055.