An estimated 5 million Americans are illegally using prescription stimulants, with the majority seeking to boost their concentration and mental stamina over extended periods of time, according to new research shedding light on amphetamine use among adults.
Published on Monday in the American Journal of Psychiatry, the study is the first nationally representative survey to combine statistics on the prevalence of prescription stimulant use with misuse, use disorders and motivations for misuse.
Overall, it found that 16 million Americans over the age of 18 are using prescription stimulants. About 400,000 people are thought to abuse stimulants.
“I was surprised at the large number of adults who use these medications,” said Dr. Wilson Compton, the study’s lead researcher and deputy director of the National Institute on Drug Abuse, one of the National Institutes of Health.
Total prescription stimulant sales for adults have surpassed those for youth, the researchers wrote, and 55 percent of total prescriptions in 2015 were to adults age 20 and older.
“We knew there had been increases,” Dr. Compton said, “but understanding that an awful lot of people over age 18 who take these medications — that most of us think of as predominantly prescribed to children and teenagers.”
Data were taken from the 2015 and 2016 national Survey on Drug Use and Health, which included responses from 102,000 adults 18 years of age and older. The survey also had respondents answer if they use and misuse prescriptions for opioids and sedatives. That data will be released in other studies.
Prescription stimulants in the survey were defined as those often prescribed for the treatment of attention-deficit hyperactivity disorder or obesity, including amphetamines like Adderall and methylphenidate, or Ritalin.
Misuse is defined as using a medication without a prescription for a reason other than as directed by a physician or in greater amounts or for longer than prescribed.
These stimulants increase the release of norepinephrine and dopamine in the brain, increasing alertness, attention, energy and a sense of euphoria. They also increases blood pressure, heart rate and respiration.
There are harmful side effects with prolonged use and abuse of the drugs — including anxiety, paranoia, psychosis, heart failure and even sudden death.
“Probably the most significant issue, though, would be becoming addicted — where people would end up with a compulsion to take them,” Dr. Compton said.
The profile of a typical abuser tended to be a single white male between 18 to 49 years old from a lower-income background who doesn’t not have a high school diploma. Members of this group also are likely to have depressive symptoms and to use legal and illegal drugs.
Of the 11 million people who use prescription stimulants properly, the profile of the typical patient tended to be a woman with private health insurance.
More than half of respondents (56.3 percent) said they use prescription stimulants for cognitive enhancement — to be alert or concentrate — followed by use as a study aid (21.9 percent). About 15.5 percent of respondents said they take the medications to “get high or being hooked,” and 4.1 percent said they use it for weight loss.
Many respondents who misused the prescription stimulants reported getting the medications from a family member or friend with a prescription (56.9 percent), and 21.8 percent said they buy or steal pills from friends or relatives.
“One of the things to keep in mind is that clinicians need to assess what patients are doing with their medications and to be consistently asking what they’re doing with leftover medications,” Dr. Compton said.
The researchers noted that despite a high level of misuse, there were low levels of disorders among this population, yet it is a trend worth worrying about.
“This substance can be misused by a broad range of individuals,” the study said.