
Drug addiction research requires but lacks a valid and reliable way to measure both the risk (propensity) to develop addiction and the severity of manifest addiction.
This paper argues for a new measurement approach and  instrument to quantify propensity to and severity of addiction, based on the  testable assumption that these constructs can be mapped onto the same dimension  of liability to addiction.
The case for this new direction becomes clear from a  critical review of empirical data and the current instrumentation. The many  assessment instruments in use today have proven utility, reliability, and  validity, but they are of limited use for evaluating individual differences in  propensity and severity.
The conceptual and methodological shortcomings of  instruments currently used in research and clinical practice can be overcome  through the use of new technologies to develop a reliable, valid, and  standardized assessment instrument(s) to measure and distinguish individual  variations in expression of the underlying latent trait(s) that comprises  propensity to and severity of drug addiction.
Such instrumentation would enhance  our capacity for drug addiction research on linkages and interactions among  familial, genetic, psychosocial, and neurobiological factors associated with  variations in propensity and severity.
It would lead to new opportunities in substance abuse prevention, treatment, and services research, as well as in interventions and implementation science for drug addiction.
Request Reprint E-Mail:   kconway@nida.nih.gov   
 
