Depression appears to drive changes in how the body processes a specific amino acid called valine, rather than the other way around. This discovery, published in Psychopharmacology, helps explain why metabolic problems often accompany poor mental health. The World Health Organization currently ranks depression as the third leading cause of the global disease burden. Experts project it will reach the number one spot by the end of the decade. Major depressive disorder is one of the most common mental health conditions worldwide, affecting how people feel, think, and handle daily activities. Depression is primarily known for its psychological toll, but it also produces physical symptoms like fatigue, appetite loss, and sleep disturbances. Many individuals with the disorder eventually develop metabolic abnormalities. Patients often experience unexplainable shifts in how their body processes energy, which has puzzled the medical community for years. Some patients develop a cluster of metabolic conditions that includes high blood pressure, high blood sugar, and abnormal cholesterol levels. Patients dealing with both psychological symptoms and metabolic syndrome face a heavier overall disease burden. …