Stein, Dan J (16. februar 2004). Clinical Manual of Anxiety Disorders (1st utg.). USA: American Psychiatric Press Inc. s. 53. ISBN978-1585620760. «Fears are common in children and adolescents. However, for some youth, these fears persist and develop into specific phobias. A specific phobia is an intense, enduring fear of an identifiable object or situation that may lead to panic symptoms, distress, and avoidance (e.g., fears of dogs, snakes, storms, heights, costumed characters, the dark, and similar objects or situations). Moreover, phobias can affect a youngster's quality of life by interfering with school, family, friends, and free-time. It is estimated that 5% to 10% of youth will develop a phobia before reaching the age of 16.»