Gene Variant Explains Anxiety and Depression After Stress Situations
New research this week in Nature Neuroscience indicates a gene variation may make people more susceptible to depression and anxiety by weakening a circuit for processing fear and negative emotions.
The research found that the short version of the gene contributes to greater general anxiety and the risk of depression following a major stress situation.
In over 200 patients examined with MRI and fMRI scans, people with the gene variation had less gray matter and weaker connections in the mood-regulating circuit. Brain scans showed that people with the less effective circuitry were more likely to have trouble dealing with the stresses of life.
Previous studies have shown that inheriting the short gene variant more than doubles risk of depression following stressful situations, and even boosts amygdala activity while viewing scary faces, and has been linked to anxious temperament. This new study revealed the failed inner workings of the brain circuitry that is responsible.
The mood regulating circuit (the amyglada and anterior cingulate region) controls the body's ability to silence an alarm in the brain when humans experience a threat or other stressor. Normally, the anterior cingulate area of the brain shuts down the fear response of the amygdala. In people with the gene variant, weakened connection between the cingulate and the prefrontal cortex allows the powerful fear alarm of the amygdala to run rampant, stimulating other negative emotional responses from the rest of the limbic brain.
"The problem isn't that you're fearful, it's that you can't stop being fearful, you can't turn it off," said Dr. Daniel R. Weinberger, co-author of the study and Director of the Genes, Cognition and Psychosis Program at the National Institute of Mental Health.
Though the findings won't help in the development of new treatments for depression and anxiety they do explain the understanding of many researchers that some people are more susceptible to anxiety and depression as a result of encountering stressful situations.
Researches estimated that how well the circuit was connected accounted for nearly 30 percent of the anxious temperament of the patients examined in the study. Previous studies concluded that people with this gene variant were more than twice as likely to develop depression.
Genetic predispositions to anxiety or depression do not in any way doom someone with a variant gene to having a mental illness. Nor does having the variant gene in patients with anxiety and depression mean that these disorders cannot be managed and even eventually overcome.
Fortunately an impressive range of scientifically supported alternative treatments successfully alleviate the symptoms of anxiety and depression. Ongoing multi-modal programs combining exercise, nutriceuticals, cognitive-behavioral therapy or clinical hypnotherapy, and relaxation techniques, have been demonstrated to beat anxiety driven depression, even in people who are highly susceptable to stress.
Author:
William Prescott is a health researcher and author. |
|
