Prevention in the assessment, Diagnosis and treatment of abnormal behaviors, refer to several activities directed at decreasing the chances that undesired future outcomes will occur.
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Prevention is a term used in Health psychology that refers to the idea that by performing a few simple behaviors consistently, such as exercising, avoiding smoking, using seat belts and others people may dramatically reduce their risk for health problems and may significantly reduce health care costs.
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The principle that, in the long run, preventive activities will be more efficient and effective than individual treatment administered after the onset of disease or problems. Both pediatric and clinical child psychology focus on the prevention of childhood problems, examples are: by providing education, establishing safety programs, and identifying and proactively treating children at risk.

Prevention also refer to activities directed at decreasing the chances that undesired future outcomes will occur.