There is a story that is frequently used to illustrate what prevention is and what it is not.
Two friends, Susan and Fernando, are fishing on a river when Fernando looks up river and sees a man in the water! He is struggling to stay afloat, so Fernando drops his fishing pole and pulls the man out of the water. The man is sputtering and cold, and Susan calls an ambulance on her cell phone to take the person to a hospital. Susan and Fernando go back to fishing. Pretty soon they look up river again and see a woman in the water! She is struggling, too, so Fernando drops his fishing pole again and pulls the woman out of the water.
She is not in very good shape, so Susan calls another ambulance to take her to a hospital. The friends return to fishing when they look up river and see a whole group of people in the water! They are struggling to stay afloat, but look like they are dragging each other down. Fernando drops his fishing pole and starts hauling people out of the water. He looks up and sees Susan walking away, up river. He calls to her to come help pull these people out of the river, and Susan responds that she is going up river to find out why all the people are ending up in the water.
What prevention is.
We go up river to find out what contributes to people abusing substances and needing treatment services. We want to know exactly what is causing people to fall into this river, which may be different from river to river. Perhaps we go upstream – like Susan - and find a fence built to keep people away from the river has fallen and needs to be rebuilt. Maybe we find a slippery slope running into the river and can plant vegetation on the slope to prevent people from falling down the slope. Maybe we find a big sign announcing, “The water’s great, jump in!” and we can take the sign down and replace it with a warning sign. So, we in prevention work to find out what is causing kids to abuse substances in our community, and then we work to reduce those risks and to build protection against substance abuse.
What prevention is not.
Once people have developed problems with substance abuse, they are more appropriately candidates for treatment services than prevention.
Institute of Medicine Continuum of Human Service
Mental health promotion interventions: Usually targeted to the general public or a whole population. Interventions aim to enhance individuals’ ability to achieve developmentally appropriate tasks (competence) and a positive sense of self-esteem, mastery, well-being, and social inclusion, and strengthen their ability to cope with adversity.
Universal prevention: Targeted to the general public or a whole population that has not been identified on the basis of individual risk. The intervention is desirable for everyone in that group. Universal interventions have advantages when their costs per individual are low, the intervention is effective and acceptable to the population, and there is a low risk from the intervention.
Selective prevention: Targeted to individuals or a population subgroup whose risk of developing mental disorders is significantly higher than average. The risk may be imminent or it may be a lifetime risk. Risk groups may be identified on the basis of biological, psychological, or social risk factors that are known to be associated with the onset of a mental, emotional, or behavioral disorder. Selective interventions are most appropriate if their cost is moderate and if the risk of negative effects is minimal or nonexistent.
Indicated prevention: Targeted to high-risk individuals who are identified as having minimal but detectable signs or symptoms foreshadowing mental, emotional, or behavioral disorder, or biological markers indicating predisposition for such a disorder, but who do not meet diagnostic levels at the current time. Indicated interventions might be reasonable even if intervention costs are high and even if the intervention entails some risk.
* Preventing Mental, Emotional, and Behavioral Disorders Among Young People: Progress and Possibilities, National Research Council and Institutes of Medicine, 2009