A long line of research links poverty and depression. Now, a study by Duke University scientists shows how biology might underlie the depression experienced by high-risk adolescents whose families are socio-economically disadvantaged.
The study, published May 24, 2016 in the journal Molecular Psychiatry, combined genetics, brain imaging and behavioral data gathered as adolescents were followed for more than three years as part of a larger study.
The results are part of a growing body of work that may lead to biological predictors that could guide individualized depression-prevention strategies.
Adolescents growing up in households with lower socioeconomic status were shown to accumulate greater quantities of a chemical tag on a depression-linked gene over the course of two years. These “epigenetic” tags work by altering the activity of genes. The more chemical tags an individual had near a gene called SLC6A4, the more responsive was their amygdala—a brain area that coordinates the body’s reactions to threat—to photographs of fearful faces as they underwent functional MRI brain scans. Participants with a more active amygdala were more likely to later report symptoms of depression.