Using someone else’s medication is the most common form of prescription stimulant misuse among adolescents, according to a University of Florida Health study, which found that 88 percent of teens who used the drugs non-medically in the past 30 days said they had obtained the medications from someone else.

“In the last 10 years a number of new stimulant medications have been approved for attention deficit hyperactivity disorder, or ADHD, treatment, and the expansion of this market, coupled with the increasing rates of ADHD diagnosis, provides greater availability of these drugs,” said lead author Yanning Wang, M.S., who conducted the study as part of her thesis work for a master’s degree in the department of epidemiology at the UF College of Public Health and Health Professions and the College of Medicine. “This raises concerns about the possible non-medical use or abuse of these medications.”

The findings appeared in the December issue of the journal Drug and Alcohol Dependence.

Drugs such as Adderall, Concerta and Ritalin are typically prescribed to help patients with ADHD stay focused and to control behavior problems. When taken incorrectly or without a prescription, the stimulants can increase blood pressure, heart rate and body temperature and decrease sleep and appetite, according to the National Institute on Drug Abuse. At high doses, they can lead to cardiovascular problems.

Wang, now a statistical research coordinator in the UF College of Medicine’s department of pathology, immunology and laboratory medicine and the department of health outcomes and policy, analyzed data from the National Monitoring of Adolescent Prescription Stimulants Study, which surveyed more than 11,000 youth ages 10 to 18 living in and around 10 U.S. cities. Interviewers recruited participants at entertainment venues, such as shopping malls, movie theaters, sports and recreation centers, arcades and skate parks. The study was carried out during four waves between 2008 and 2011.

About 7 percent of all respondents reported they had used a prescription stimulant during the past 30 days. Among those 750 adolescents, 54 percent reported some type of non-medical use, such as taking more pills than prescribed by their doctor, using someone else’s medication, or smoking, snorting or sniffing the medication instead of taking by mouth. Using someone else’s medication was the most frequently reported form of misuse at 88 percent, followed by taking more medication than prescribed at 39 percent.

“It is so important for physicians and parents to counsel youth who have prescription stimulants to never share their medications,” said co-author Linda B. Cottler, Ph.D., M.P.H., a dean’s professor, chair of the department of epidemiology and Wang’s mentor.

The UF study was unique in that it differentiated two different types of non-medical users: those who exclusively used stimulants non-medically, and teens who reported both using their own stimulant medication as prescribed and some form of non-medical use within the past 30 days. This group of medical and non-medical users is an important group for future study, Wang said, because they could be serving as a source for shared or traded prescription stimulant medication.

Teens who only used stimulants non-medically reported more conduct problems at home and school and higher rates of using other substances, including tobacco, alcohol and illicit drugs. That group was also more likely to have close friends who have tried other drugs, suggesting they are in “a circle of risk taking,” said Cottler, also the College of Public Health and Health Professions’ associate dean for research.

Understanding differences in behavior and friend networks between the two types of non-medical users can help experts develop targeted educational programs to prevent prescription stimulant misuse, said Wang, who is currently working with Florida’s Prescription Drug Monitoring Program to analyze multiple sources of data to understand current and emerging trends of prescription drug abuse.

The National Monitoring of Adolescent Prescription Stimulants Study was implemented by the University of Florida and Washington University in St. Louis under contract from Pinney Associates Inc., with funding provided by Shire Development LLC and Noven Therapeutics.