A growing number of workers in a wide variety of professions are abusing stimulants in an effort to stay competitive, experts tell The New York Times. Abuse of stimulants to treat attention deficit hyperactivity disorder (ADHD), such as Adderall, has long been an issue for college students. A recent analysis estimated that 17% of college students misuse ADHD drugs. There are no reliable estimates of how many American workers misuse stimulants, but dozens of people interviewed by newspaper said they and co-workers misused stimulants. These drugs, when taken in high doses, can cause anxiety, addiction and hallucinations. Some doctors and medical ethicists are concerned there is pressure in some workplaces to use stimulants in an attempt to become more productive.