Many neurotransmitters are affected when the body is under the increased stress and anxiety that accompany a panic attack. Some include serotonin, GABA (gamma-aminobutyric acid), dopamine, norepinephrine and glutamate. More research into how these neurotransmitters interact with one another during a panic attack is needed to make any solid conclusions, however.
People with generalized anxiety disorder (GAD) display excessive anxiety or worry, most days for at least 6 months, about a number of things such as personal health, work, social interactions, and everyday routine life circumstances. The fear and anxiety can cause significant problems in areas of their life, such as social interactions, school, and work.