GAD is Generalized Anxiety Disorder, a recognized psychiatric disorder. The Diagnostic and Statistical Manual of Mental Disorders (DSM–5) lists the following diagnostic criteria for GAD:
- Excessive anxiety and worry (apprehensive expectation), occurring more days than not for at least 6 months, about a number of events or activities (such as work or school performance).
- The individual finds it difficult to control the worry.
- The anxiety, worry, or physical symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.
- The anxiety and worry are associated with 3 (or more) of the following 6 symptoms (with at least some symptoms having been present for more days than not for the past 6 months):
- Restlessness or feeling keyed up or on edge.
- Being easily fatigued.
- Difficulty concentrating or mind going blank.
- Muscle tension.
- Sleep disturbance (difficulty falling or staying asleep, or restless, unsatisfying sleep).
Scientists still don’t know the precise cause of GAD, but there seems to be consensus that it’s connected to something going haywire in the amygdala, the part of the brain that is responsible for detecting and responding to threats. It’s not clear yet why the brains of people with GAD are different from other people’s brains, but it’s well established that they are.
You can read more about GAD at the website of the U.S. National Institute of Mental Health.