Wilens TE, Gignac M, Swezey A, Monuteaux MC, Biederman J
J Am Acad Child Adolesc Psychiatry. 2006;45:408-414
To estimate the rate of misuse of medications prescribed for attention-deficit/hyperactivity disorder (ADHD), 7 relevant questions were posed to 55 subjects with ADHD (82% male, mean age 20.8 years) and to 43 controls (47% male, mean age 23 years) receiving psychotropic drugs for non-ADHD treatment at 10-year follow-up during a longitudinal case-control study. Four of the yes-or-no questions inquired about using medication for euphoria or selling medication during the 4 preceding years. Among subjects with ADHD, 96% were taking stimulants and 31% were taking serotonin reuptake inhibitors (SRIs); among the controls, 10% were taking stimulants and 80% were taking SRIs. A few subjects in each group were taking antipsychotics, benzodiazepines, or other psychotropics.
The absolute number of subjects reporting misuse or sale of medication was small. On each of the 7 questions, more subjects with ADHD affirmed such behaviors than did controls, but only for selling medication was the difference statistically significant (11% vs 0%, P < .05). Among ADHD subjects who had misused or sold medication, 31% had conduct disorder and 53% had a substance-use disorder; among those who sold medication, all had such a comorbid diagnosis. The medication most often misused or diverted was immediate-release methylphenidate, followed by immediate-release mixed amphetamine salts. Only 10% of subjects had received extended-release stimulant medication, none of whom reported having misused or sold it.
The major shortcoming of the study is reliance on self-report using an unvalidated instrument. Of those who improperly used medication, 31% had conduct disorder, a criterion of which is lying. Presumably, some proportion of those who denied improper use also had conduct disorder. Recall bias is a given in retrospective reports and, in this case, the reliability of responses is even more in question. Hence, the estimate is likely low. The researchers, however, say that their findings are similar to previous estimates. They also point out that their sample size was predominantly white and middle class and, therefore, not representative of all clinical populations. In addition, the control subjects, none of whom had ADHD, took medications less liable to abuse and diversion, which should be noted in interpreting the results. Nonetheless, the fact that a large proportion of subjects who improperly used their stimulants had conduct disorder or a substance-use disorder is an important finding for clinicians to note.