In Europe about 3% of the population has a panic attack in a given year while in the United States they affect about 11%. They are more common in females than males. They often begin during puberty or early adulthood. Children and older people are less commonly affected. A meta-analysis was conducted on data collected about twin studies and family studies on the link between genes and panic disorder. The researchers also examined the possibility of a link to phobias, obsessive-compulsive disorder (OCD), and generalized anxiety disorder. The researchers used a database called MEDLINE to accumulate their data. The results concluded that the aforementioned disorders have a genetic component and are inherited or passed down through genes. For the non-phobias, the likelihood of inheriting is 30%-40% and for the phobias, it was 50%-60%.
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.