GeneticsAs a clinician, when someone comes to my office with some symptoms of GAD (such as excessive worry or constant anxiety), I immediately try to gather information about family members that may also have anxiety disorders or GAD. Almost without fail, someone (parent, grandparent, sibling) has some experience with significant anxiety as well. If not, often it is because the person simply does not have the information. This link is not just anecdotal: Researchers have shown a strong link for anxiety disorders in families and have been working hard to understand the underlying genes that create this life experience.
Brain ChemistrySome parts of our brain chemistry are also involved in GAD. Most notably the brains of people with GAD have abnormal levels of serotonin and norepinephrine. The most popular treatments for GAD work to correct this. It is unclear whether genes, some sort of environmental stress, or another factor cause these levels to be different. But it is the source of ongoing research.
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