Among the features that distinguish DIS are their structure (human network or organization systems) and the range of information sources used. Indicators of drug use can be placed on a continuum of sensitivity that ranges from leading-edge indicators to lagged indicators. Sensitivity implies volatility, because sensitive indicators also react to fluctuations that do not become trends. DIS conventionally are largely reliant upon lagged indicators. What is required are DIS that combine a critical information processing function with the ongoing systematic collection of data from a range of data sources. The purpose of such a process is to identify not only what is known about the current consumption of illicit drug use, but also what information is required to support the future development of effective policy and interventions. Such an integrated information system must incorporate data from sources that are currently poorly developed. Their task is to act as an alarm bell that signals changing drug-consumption patterns and thereby trigger both the collection of more structured data sets and discussion of what might be appropriate responses far earlier than is currently the case. 2 tables, 1 figure, a selected glossary, contact information, and 46 references