Link Between Stress and Mental Disorders Revealed
People who suffer from chronic stress are more likely to experience mental health conditions, such as anxiety and mood disorders, later in life. A new study pinpoints the source: Chronic stress generates larger amounts of myelin-producing cells in the brain than usual, leading to an excess of white matter and therefore, fewer neurons.
The imbalance of gray matter (neurons which store and process information) to white matter (the axons which create the network through which information travels) disrupts communication within the brain and leave long-lasting structural changes.
Researchers at UC Berkeley studied neural stem cells located in the hippocampus. In cases of chronic stress, they found that these stem cells, rather than transform into neurons or glial cells called astrocytes, become oligodendrocyte—a cell that produces myelin.
Because chronic stress not only increases the amount of myelin-producing cells, but also decreases the amount of cells that become neurons, researchers believe these structural changes may also affect memory and learning capabilities.
“Our findings could provide insight into how white matter is changing in conditions such as schizophrenia, autism, depression, suicide, ADHD and PTSD,” researchers concluded.
Chetty S, Friedman AR, Kaufer D, Pleasure D, Palmer TD et al. Stress and glucocorticoids promote oligodendrogenesis in the adult hippocampus. Molecular Psychiatry. doi:10.1038/mp.2013.190