Attention Research Update

March 2006

"Helping parents, professionals and educators stay informed about new research on ADHD"

David Rabiner, Ph.D.  Senior Research Scientist, Duke University


Support for Attention Research Update is provided by Cogmed

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New Research Findings on the Misuse of ADHD Medications

Although concerns about the misuse of stimulant medications used to treat ADHD have become widespread, data regarding the magnitude of this problem is relatively limited.

In a prior issue of Attention Research Update I summarized information available at the time, which included the following study findings:

  • The Massachusetts Department of Public Health conducted an anonymous survey of 6000 students and reported  that 13% of high school students and 4% percent of middle school students acknowledged the "illicit, unprescribed use" of stimulant medications. 
  • In a survey of 161 students with ADHD attending a number of schools in central Wisconsin, 16% reported that they had been approached to sell, give, or trade their medication. 
  • A survey of 651 students - including 50 with prescriptions for ADHD medication - revealed that nearly one-third of those with prescriptions had been approached to give away or sell their meds.  Over 50% of students without ADHD reported that they had seen a peer with ADHD being asked to sell or give away their medication.
  • Data from the 2001 National Household Survey on Drug Abuse conducted by the Substance Abuse and Mental Health Services Administration (SAMHSA) indicates that 2.2% of 12-17-year-olds and 3.4% of 18-25-year-olds reported the non-medical use of stimulant medication during the prior year. 
  • In 2000, the National Institute on Drug Abuse (NIDA) reported that the annual prevalence of nonmedical abuse of methylphenidate by high school seniors peaked at 2.8% in 1997 and 1998 compared with .1% in 1992.  These figures dropped to 2.4% in 1999 and 2.2% in 2000.

Limitations of Prior Studies

Findings summarized above indicate that nonmedical use of stimulant medications is not uncommon.  However, because nonmedical use is defined as reporting the "...use of any prescription-type stimulant, even once, without a doctor's prescription", individuals misusing stimulant medications a single time are not distinguished from those whose misuse is a more serious problem.

In addition,data on the non-prescribed use of stimulant medications provides no information on the misuse by individuals with ADHD for whom the medications have been prescribed.  Thus, although data summarized above indicate that students with prescriptions are approached to sell or give away their stimulant medication on a disturbingly frequent basis, they do not tell us whether those with prescriptions misuse their own medication.  Such misuse could include taking medication more often than prescribed, taking higher doses than prescribed, or intranasal administration (i.e., snorting) in an attempt to induce a high.


Recent Studies


In contrast to prior studies on this topic, a recent study attempted to differentiate between one time/infrequent nonmedical use and nonmedical use that was more problematic.  The study will be published in the upcoming issue of the journal Drug and Alcohol Dependence (Kroutil, L., et al., (2006). Nonmedical use of prescription stimulants in the United States.  Alcohol and Drug Dependence).

The authors used data from the 2002 National Survey on Drug Use and Health, an annual survey of the US civilian population aged 12 or older to estimate the rate of nonmedical use of stimulant medications.  Because the sample size wass large (over 50,000) and representative of the general US population, reliable estimates of nonmedical use for the entire population could be made.

As in prior studies, nonmedical use was defined as using any prescription-type stimulant even once without a doctor's prescription or for the experience or feeling it caused. The latter type of misuse - taking only for the "experience or feeling it caused" could apply to individuals with prescriptions who deviated from their prescribed use.  However, the data was not broken out in a way that permitted an examination of this important issue.


Results

Results indicated that an estimated 7.3 million persons aged 12 or older had misused at least one ADHD stimulant, in addition to other stimulant medications, at least once in their lifetimes; this represented 2.6% of persons aged 12-17 years and 5.9% of persons aged 18-25 years.  The corresponding perentages for use during the prior 12 months were 1.7% and 2.0% respectively.

Of these 7.3 million, 2.9 million had misused ADHD stimulants exclusively.  During the prior 12 months, .9% of 12-17-year-olds and 1.3% of 18-25-year-olds had engaged in the nonmedical use of ADHD stimulants exclusively.

Misuse of ADHD stimulants most frequently involved short acting Ritalin/methylphendiate and Dexedrine.  However, nonmedical use of other stimulants, including longer-acting formulations were also reported.  Nonmedical use of longer acting formulations such as Concerta, however, was far less frequent.


Serious forms of Nonmedical Use

The authors estimated the percentage of nonmedical users of ADHD stimulants whose misuse was more serious, i.e., those who met criteria for stimulant dependence or stimulant abuse.

Individuals identified as stimulant dependent demonstrate at least 3 of the following symptoms:

* Tolerance - requiring higher doses to attain the same effect;
* Withdrawal - experience of withdrawal symptoms when deprived of stimulants;
* Using stimulants more often than intended;
* Desiring to stop/cut back but being unable to;
* Considerable time spent obtaining stimulants or recovering from their effect;
* Important activities given up or neglected because of stimulant use;
* Continued use despite knowledge of problems caused or aggravated by stimulant use;

Stimulant abuse represents a somewhat less severe form of nonmedical stimulant use and is diagnosed in individuals who while not stimulant dependent, show at least 1 of the following 4 symptoms:

* recurrent failure to meet important responsibilities due to stimulant use;
* recurrent use of stimulants in situations where it is likely to be dangerous;
* recurrent legal problems arising from use;
* continued use despite recurrent problems aggravated by use;

Among individuals ages 12-17 who engaged in any nonmedical use of stimulant medications during the prior year, including ADHD stimulants, 2.2% met criteria for stimulant dependence and an additional 3.5% met criteria for stimulant abuse.  For those ages 18-25, the corresponding figures were 3.1% and 3.5% respectively. 

According to the authors, this translates into about 75,000 persons ages 12-25 who qualified for DSM-IV diagoses of stimulant dependence or stimulant abuse in the prior 12 months.  This represents about .06% of the total population in this age range.

Among those who had misused ADHD stimulants exclusively, the estimated number of dependence and abuse cases was 24,000; this represents about .02% of the population in this age group.


What about misuse by those with prescriptions?

The results summarized above suggest that about 2% of persons ages 12-25 each year engage in the nonmedical use of ADHD stimulants at least once during a given year.  In addition, among those who misuse ADHD stimulants exclusively, nearly 25,000 meet criteria for stimulant dependence or abuse during the year.

Although these concerning figures highlight that ADHD stimulants are often diverted for nonmedical purposes, they provide no information on the misuse of ADHD medications by those for whom they are prescribed.  For parents concerned about using stimulant medications for their child, as well as for physicians who prescribe these medications, this is an extremely important issue.

Unfortunately, data on the misuse of ADHD stimulants among prescribed users is extremely limited.  One of the few studies I have seen on this topic was presented at the 2005 annual meeting of the American Psychiatric Association by Dr. Timothy Wilens, the director of Substance Abuse Services in the Pediatric and Adult Psychopharmacology Clinics at Massachusetts General Hospital in Boston. 

Participants were 98 individuals receiving medication for ADHD who were part of a 10-year longitudinal study.  Over half the participants were diagnosed with a comorbid behavior disorder and/or substance use disorder while the remainder had ADHD alone.  Participants' average age was just over 20 years.

These individuals were asked about selling their ADHD medication.  They were also asked about their own misuse, i.e., using them more often then prescribed.

Eleven percent of those with comorbid difficulties reported having sold their ADHD medication. Individuals with ADHD alone never reported this.

Regarding misuse, 22% of the comorbid subjects had misused their medications by using them too frequently vs. 5% of participants with ADHD alone.  Information on the frequency of misuse, or the consequence of misuse, was not available.


Summary and Implications

Results from these studies highlight the need to be concerned about the nonmedical use of stimulant medications used to treat ADHD.  Nonmedical use by individuals without a prescription is not an isolated phenomena, and thousands of individuals between 12 and 25 report symptoms that rise to the level of dependence or abuse. 

Although this is concerning, it is important to recognize that the percentage of the population for whom nonmedical use of ADHD stimulants rises to this level is quite small.  Thus, an estimated 75,000 cases would represent about .06% of the US population in the 12-25 age range.

It is also important to recognize that these figures do not pertain to the misuse of ADHD stimulants by those for whom such medications are prescribed.  As noted above, data on the misuse of ADHD medications by those with prescriptions is limited.  However, it appears that such misuse is more likely in individuals who have behavior disorders in addition to ADHD and/or who also have a substance use disorder. How often individuals misuse their medication, and what the consequences of this misuse may be, however, is not known. Clearly, additional research on this issue is needed.

The authors of the large survey study summarized above conclude their report by stating:

"The concerns about diversion of prescription stimulants should not be construed as recommendations against the use of these medications to treat ADHD or other disorders under appropriate medical supervision... Several recent studies have indicated no increased risk for substance experimentation or disorders among youth who were treated with stimulants for ADHD, or reduced risk relative to persons whose ADHD was not treated pharmacologically." 

Thus, many ADHD experts and physcians would likely agree that the misuse and abuse of these medications by some should not be construed as an argument against their legitimate use in individuals with ADHD. 

These data do highlight the need to be vigilant about the potential misuse of ADHD stimulant medications, however, and for parents, professionals, and educators to recognize that many adolescents prescribed such medication may be approached by others who wish to use it for nonmedical purposes.  Educating children and teens that peers may approach them to buy medication, and how they should respond should this occur, would thus seem to be very important. 

In addition, data from the smaller study of misuse by those prescribed ADHD medication suggest that misuse is more likely to occur in those with comorbid behavior disorders and/or substance use disorders.  Therefore, extra caution needs to be exercised when treating such youth with stimulant medications, and physicians may want to start treatment with a nonstimulant therapy. If stimulant medications are required, a long-acting stimulant coupled with rigorous monitoring would seem like the safest course.

These data also underscore the ongoing need for research into the development of nonmedical treatments for ADHD that can be as effective in managing core symptoms as stimulant medications.  I try to include summaries of solid research on such treatments in Attention Research Update whenever I come across such work, and will continue to do so.

Thanks again to Cogmed for supporting this issue of Attention Research Update.

(c) 2006 David Rabiner, Ph.D.

Information presented in Attention Research Update is for informational purposes only, and is not a substitute for professional medical advice.  Although newsletter sponsors offer products and services that I believe will be of interest to subscribers, sponsorship of Attention Research Update does not constitute a specific endorsement or guarantee of any company's product or services.