Key Informant Signal Detection System   Surveys patients recruited by designated key informants seeking treatment for dependence or addiction from a variety of treatment facilities in rural, urban and suburban areas. Provides prescription drug abuse data from the perspective of the patient.   Theodore J. Cicero, Ph.D., Washington University in Saint Louis, is the principal investigator of this signal detection system.    For more information about participating in the Key Informant Signal Detection System, please contact Alethea Paradis.