Kynurenine pathway linked to adolescent depression risks

Depression affects 280 million people globally and is more common in women than in men. This trend often starts during adolescence. Researchers are now looking at the kynurenine pathway, a biological process believed to be linked to depression, especially in teenagers. This is the first study to explore this pathway in adolescents, focusing on differences between boys and girls. The study was published in Biological Psychiatry and funded by MQ Mental Health Research. It involved 150 teenagers from Brazil, aged 14 to 16. The participants were divided into three groups based on their risk of depression: low risk, high risk, and those already diagnosed. Each group included an equal number of boys and girls. Researchers measured levels of kynurenic acid, which protects the brain, and quinolinic acid, which can harm it. They found that teenagers at high risk or diagnosed with depression had lower levels of kynurenic acid, especially among girls. This suggests girls might be more vulnerable to depression due to imbalances in the kynurenine pathway. The study also analyzed proteins that indicate inflammation, which can occur during stress or illness. Higher levels of inflammation were linked to increased production of harmful chemicals in the kynurenine pathway. This link was stronger in teenagers who were already experiencing depression. Three years later, the study found that girls with ongoing depression had more toxic metabolites than those who recovered. This suggests that high neurotoxic activity could make it harder for some adolescents to overcome depression. The researchers believe that understanding the kynurenine pathway could help identify teenagers at risk of persistent depression, especially girls. This insight may lead to more targeted support, combining medication and lifestyle changes to help manage depression in young people.