A standard dictionary defines intervention as an influencing force or act that occurs in order to modify a given state of affairs. In the context of behavioral health, an intervention may be any outside process that has the effect of modifying an individual's behavior, cognition, or emotional state. For example, a person experiencing stresssymptoms may find a variety of interventions effective in bringing relief. Deep breathing, vigorous exercise, talking with a therapist or counselor, taking an anti-anxiety medication, or a combination of these activities are all interventions designed to modify the symptoms and potentially the causes of stress-related discomfort.

The term is also used to describe a specific process designed to break through denialon the part of persons with serious addictive disorders. Interventions in this sense of the word involve carefully orchestrated confrontations in which friends, family members, and (in many cases) employers confront the person with the negative impact and consequences of his or her addiction. The goal of an intervention is to bring the addicted person to acknowledge that he or she suffers from a disorder and agree to treatment. This goal, however, is not always realized.