Herbert is a 32-year-old lawyer seeking treatment for his irrational fear of thunderstorms. He has had this fear since the age of 4, and throughout life he has developed various strategies for coping with his fear. Whenever possible, he avoids going outside when a storm is forecast. Not only will he stay within a building, but he will ensure that he is in a room with no windows and no electrical appliances. As his job has grown in responsibility, Herbert has found that he can no longer afford to take time off because of his fear, which he knows is irrational. A) What specific disorder would you diagnose Herbert with, if any?

B) Identify one or more possible causes of Herbert's symptoms.