Which of the following statements is true of generalized anxiety disorder?

A) An individual suffering from generalized anxiety disorder experiences persistent anxiety for a maximum of one month.
B) An individual suffering from generalized anxiety disorder is nervous most of the time.
C) Generalized anxiety disorder does not have any impact on the physical health of an individual.
D) Generalized anxiety disorder is often caused due to an elevation in the levels of the neurotransmitter GABA.

Generalized anxiety disorder is characterized by excessive worry and anxiety about everyday activities and events. This anxiety can be persistent and ongoing, lasting for months at a time. It can also be accompanied by physical symptoms such as restlessness, muscle tension, and difficulty sleeping. Therefore, option A is incorrect. Option C is also incorrect as anxiety can have a significant impact on a person's physical health. Finally, option D is incorrect as GABA levels are usually decreased in people with generalized anxiety disorder.