Gene variants shield against depression

Not all child-abuse survivors are created equal. A minority possess specific variations in a stress-regulating gene that protect them from developing serious forms of depression as adults, a new study finds.

Adults who were abused as children physically, sexually, or emotionally, but hadn’t inherited the key gene variations, displayed twice as many symptoms of moderate or severe depression as did abuse survivors who carried the protective variations, says Kerry J. Ressler of Emory University in Atlanta.

These DNA alterations occur along a gene that spurs production of a cell receptor for corticotropin-releasing hormone, a stress hormone thought to influence depression. Researchers suspect that abuse or other extreme childhood stress lead to overactivity of various stress hormones, thus raising the likelihood of later depression.

The scientists interviewed 621 adult survivors of childhood abuse and obtained blood samples for DNA testing. About 1 in 3 volunteers possessed gene variations linked to having no or mild symptoms of depression, Ressler’s group reports in the February Archives of General Psychiatry.

Inheriting a set of three genetic variations from both parents provided child-abuse victims with the strongest buffer against depression as adults. Depression worsened among abuse victims who inherited one copy of the protective set of variations and reached a peak of severity among those who possessed no copies of it.