The University of Arizona

Illicit Drug Screening, Brief Intervention, and Treatment Placement
Brief Interventions:

If drug screening indicates that substance use may be a problem, a brief intervention can be conducted to help the individual reduce or discontinue their substance use. 

A brief intervention by definition is an intervention designed to promote behavior change.  It is not a treatment, rather it is a pretreatment tool.  It typically includes an initial 5 to 20 minute session, and can include educational materials and up to 3 follow-up contacts.