The drugs are normally prescribed to treat attention deficit hyperactivity disorder (ADHD), but healthy students use them to get a leg up in school, by improving focus, concentration and memory.
Adrenaline, or epinephrine, is a hormone that dilates an individual's air passages and increases his heart rate when he is faced with a stressful situation. The hormone is secreted from the adrenal glands to help ensure survival under dangerous situations.
An adrenaline rush can have detrimental effects on health. In people with heart disease, it can cause a weakening of the heart muscle, heart failure or a heart attack. It can also affect the brain in negative ways.