Suddenly she heard someone call her name--Laurie!--but no one else was in the room. Feeling irritated, Laurie looked around the apartment. It was empty. Maybe someone was in the hallway? Or at the door? She found no one. Realizing that she was completely alone, Laurie felt chills run up her spine. Was she crazy?
Perhaps no other symptom is as instantly associated with insanity--some 70 percent of schizophrenics hear voices that regularly interrupt their thoughts, as do 15 percent of those who have mood disorders--but auditory hallucinations are not necessarily a sign of mental illness. They can arise as symptoms in any number of conditions, including Alzheimer's and Parkinson's diseases and temporal lobe epilepsy. In addition, episodes can occur in the absence of any physical or psychological problem.