The number of young adults, aged 20–44 years, receiving prescriptions for adult attention-deficit hyperactivity disorder has more than doubled in just 4 years, according to an analysis by Medco Health Solutions Inc.
And the increase in prescriptions for adult ADHD is likely to continue, predicted Lon Castle, M.D., director of medical policy and programs for Medco.
The analysis, based on a random sample of 2.4 million patients from the company's 60 million member database, showed that just over 1% of all adults were on ADHD medications in 2004, compared with 0.5% in 2000.
Medco is in the business of managing prescription drug benefit programs for public and private employers, health plans, labor unions, and government agencies.
The ADHD analysis, part of the company's annual Drug Trend Analysis, was highlighted on Sept. 15, 2005, at Medco's Best Practices Workshop in Chicago.
Dr. Castle pointed to recent epidemiologic studies indicating that about 4.4% of the adult population have ADHD, but only about 20% of these people have been properly diagnosed.
Increased awareness of adult ADHD among the medical community and the general population is likely to result in further increases in prescription rates.
In addition to the overall increase in adult ADHD prescriptions, the study uncovered several other interesting facts. For example, the use of ADHD medication increased 44% faster among women aged 20–44 years than it did among men in the same age group.
Furthermore, the most recent data show that in 2004, women aged 20–64 years used ADHD medications just as frequently as did men in the same age group. This is noteworthy, because in the pediatric population about twice as many boys as girls use ADHD medication.
“[This finding is] consistent with the science, in that more women relative to men present in adulthood,” said Lenard Adler, M.D., director of the adult ADHD program at New York University, in an interview.
“Women tend to have more inattentive symptoms in general, and therefore, they have more trouble with daydreaming and distraction and organization and planning, rather than being more frankly hyperactive and disruptive [as are boys],” Dr. Alder said.
In 2004, nearly 78% of all adult ADHD prescriptions were for brand-name medications, a 30% increase since 2000 in the use of brands.
“Usually, we're talking about people switching to generic drugs,” Dr. Castle said in an interview. “We see the switch in this category to brand name drugs, which are going to be more expensive.”
He attributed this unusual pattern to the fact that adults are more likely to take the newer, extended-release ADHD medications, which have not yet gone off patent.
This is likely to change later this year and early in 2006, when Concerta (extended-release methylphenidate HCl) and Adderall XR (an extended-release mixture of several amphetamines) are both scheduled to lose their patent protection.
Dr. Adler cautioned that the increase in adult ADHD prescribing is positive, but still insufficient, because such a large percentage of adults with the disorder remain undiagnosed and untreated.
“The consequences of not getting it treated are really significant,” he said. “We know that adults with ADHD are more likely to be unemployed or underemployed. We know they're more likely to be divorced or separated. They're more likely to smoke. If untreated, they're more likely to use substances. They're more likely to have motor vehicle accidents.” And he referred to a recent study showing that the annual lost household income from ADHD is about $77 billion.
Some skeptics contend that adult ADHD is not a real disorder, but Dr. Castle said the evidence suggests otherwise. “The medical community and our health agencies in the government are also recognizing that this is real and that we're just seeing the tip of the iceberg. We're kind of sounding a warning.
“Rather than burying their heads in the sand, it might be better for the managed care companies to really take a critical look at this and do some planning.”