Adderall is the brand name of a prescription medication that contains the stimulant drug amphetamine, as well as a closely related stimulant called dextroamphetamine. This medication is commonly used to control the symptoms of attention-deficit hyperactivity disorder (ADHD), and doctors also sometimes prescribe it for treatment of the sleep disorder narcolepsy. Adderall has gained significant popularity among some high school and college students as illicit study aids. When abused in this or any other way, Adderall can lead to a heart attack. Adderall Basics Amphetamine comes in two basic forms, called levoamphetamine (commonly known simply as amphetamine) and dextroamphetamine. Essentially, the molecules of these chemicals are mirror images of one another; this means they contain the same chemical configuration, but have different orientations in three-dimensional space. Doctors and scientists refer to these types of closely related molecules as stereoisomers. Inside the body, the difference in spatial orientation between levoamphetamine and dextroamphetamine produces a difference in drug effects, and even at low, therapeutic doses, levoamphetamine is significantly more powerful than dextroamphetamine. For this reason, Adderall contains 75 percent dextroamphetamine and only 25 percent levoamphetamine. The drug comes in forms that include both a standard-release tablet and an extended-release capsule. Heart Attack Basics A heart attack occurs whenever the heart muscle is robbed of its oxygen supply and doesn't have the means to function properly or stay alive. In most people, oxygen starvation in the heart muscle stems from a blockage in the blood-bearing arteries that extend into the muscle. The main underlying cause of this type of blockage is hardening of the arteries and subsequent formation of a cholesterol-based substance, called plaque, on the artery walls. When plaque forms, it encourages abnormal accumulation of blood components called platelets; when enough platelets accumulate, a blood clot can form and stop oxygen-rich blood from passing through the affected artery and feeding the heart. In addition to this process, potential causes of oxygen starvation and a heart attack include insufficient pumping of blood from the heart to the arteries (heart failure), dangerous instability in the heartbeat (arrhythmia), and an abnormal, restrictive spasming in the heart's arteries called vasospasm. Adderall's Effects Both amphetamine (levoamphetamine) and dextroamphetamine produce spikes in the body's levels of chemicals called neurotransmitters. In the brain, the main affected neurotransmitter is dopamine, which plays a primary role in creating the euphoric effects associated with amphetamine use. In the body, the main affected neurotransmitter is norepinephrine, which plays a primary role in the activation of a portion of the nervous system called the sympathetic nervous system. Dextroamphetamine achieves most of its effect by boosting dopamine levels in the brain, while amphetamine achieves most of its effect by boosting norepinephrine levels in the sympathetic nervous system. In terms of heart attack risk, the most important ingredient in Adderall is amphetamine. When this drug increases norepinephrine levels, the resulting rise in sympathetic nervous system activity triggers changes in cardiovascular function that include elevations or intermittent surges in blood pressure, an abnormally rapid heartbeat (tachycardia), and varying degrees of vasospasm. According to a study published in 2009 in the Journal of the American Board of Family Medicine, additional damaging changes caused over time by the presence of amphetamine can include direct injury to the cells in the heart muscle and rapid hardening of the heart's arteries. Contribution to Heart Attack Risks The authors of the study stress that heart damage associated with the proper use of Adderall is extremely rare. However, people who abuse Adderall as a study aid (or for any other purpose) typically take much more of the medication than a doctor would prescribe for ADHD or narcolepsy treatment. They also take the medication without the benefit of the sort of medical review that can catch potential heart susceptibilities in candidates for Adderall use. In combination, these facts can produce significant heart attack risks in any given Adderall abuser. In addition to a heart attack, Adderall abusers also increase their risk for cardiac arrest. This condition occurs when the heart muscle suddenly stops pumping and blood flow to the body ceases. People experiencing a heart attack or cardiac arrest can die in a narrow window of time with little or no advance warning.