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.
In turn, this stimulates insulin release which can lead to an increase in appetite. 1  Adrenaline increases alertness and metabolism by helping fat cells release energy. 2  When the immediate stress is over, the adrenaline levels return to normal. 3  But, cortisol lingers to help bring the body back into balance after stress.