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Improving outcomes in adolescents, adults with ADHD

Wednesday, December 12 2007 | Comments

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What's This? Approximately 7% to 8% of children and 4.4% of adults in the United States have attention-deficit/hyperactivity disorder, but only 50% and 10% of those who meet ADHD criteria, respectively, receive treatment, according to Scott Kollins, director of the Duke University ADHD Program.

"The assertion [is] that this is a disorder [for which] we are overmedicating our kids. In fact, we're not. ... What's happening though is ... we're actually treating a lot of people that don't really meet the full criteria for ADHD. So it's purely a matter of misdiagnosis as opposed to overdiagnosis or overtreatment," he said.

Kollins noted that studies have shown a range of adverse outcomes for patients with ADHD, such as lower academic achievement, higher divorce rate, and lower occupational/vocational success. In addition, these patients have an increased risk of other psychiatric problems, accidents and emergency department visits, driving accidents/tickets, and arrest/incarceration.

Diagnosing ADHD in adults is challenging, as the DSM-IV criteria were developed largely for children aged 6 to 12 years and the symptom criteria are developmentally inappropriate for adults in many cases, especially for the hyperactive-impulsive symptoms, according to Kollins.

"Most of the adults that I've seen in my years of practice are generally able to hold it together well enough not to run about or climb on things excessively," Kollins noted.

In addition, there appear to be challenges in establishing DSM-IV criteria for adults despite ADHD being a valid diagnosis in these patients, he said. For example, whereas children have parents and teachers to report on the child's symptoms, self-reporting for adults may be difficult or unreliable. Adults also have a wide range of settings in which to assess their symptoms, while the settings for children do not vary as much.

Establishing the presence of symptoms in childhood is another challenge in establishing DSM-IV ADHD criteria for adults.

"[P]eople can't remember what they did last week, let alone what they did 25 years ago. So really being able to get a good sense of whether or not the symptoms were present early on in childhood can be difficult," Kollins stated.

Adults also have more comorbid disorders, which can make differential diagnosis more difficult.

To resolve some of these challenges, the use of validated and psychometrically sound diagnostic instruments and rating scales is helpful. However, there is little in the way of current, comprehensive practice parameters for the assessment of ADHD in adults, although this will change in the next few years, especially with the development of DSM-V criteria, he said.

Kollins also noted that an ADHD diagnosis may be missed because patients normally do not seek help as a result of their ADHD symptoms, but rather they seek help for the functional impairments that result from the symptoms, such as poor parent-child interactions, poor peer relations, impaired school performance, lower educational attainment, and marital and financial difficulties.

"Most of you who are not in ADHD clinics don't see patients presenting with primary ADHD," said Dr. David Goodman, director of the Adult Attention Deficit Disorder Center of Maryland. "They present with major depressive disorder, chronic dysthymia, or bipolar disorder as their primary presentation."

In fact, of adults with ADHD, >38% have another mood disorder such as MDD (18.6%), dysthymia (12.8%), or bipolar disorder (19.4%), according to research cited by Dr. Goodman. In addition, he noted, 47% of adults with ADHD have some sort of anxiety disorder such as obsessive-compulsive disorder (2.7%), agoraphobia (4%), generalized anxiety disorder (8%), panic disorder (8.9%), posttraumatic stress disorder (11.9%), or social phobia (29.3%).

A diagnostic prioritization for pharmacotherapy should be followed when treating these disorders. For instance, Dr. Goodman suggested that alcohol and substance abuse disorders should be treated first, followed by mood disorders, anxiety disorders, and then ADHD. However, the order of treatment should take into account the severity of the concurrent disorders.

"The object is to treat one without making the other worse," he added.

Dr. Goodman listed methylphenidate hydrochloride, OROS methylphenidate, controlled-delivery methylphenidate, methylphenidate transdermal system, and atomoxetine among the ADHD drugs with adolescent indications. Drugs with adult indications include dexmethylphenidate hydrochloride, mixed amphetamine salts extended release, and atomoxetine.

Off-label drugs used to treat ADHD include bupropion hydrochloride, clonidine hydrochloride, guanfacine, and modafinil. Dr. Goodman said he uses these drugs as adjuncts for patients who have residual hyperactivity or sleep disturbances.

When comparing these drugs for their effect in treating ADHD, effect size is more clinically relevant than statistical significance because statistical significance only shows that the effect did not occur by chance, while effect size measures the magnitude of the difference, according to Dr. Goodman.

Of the drugs approved for adult ADHD, he continued, mixed amphetamine salts have an effect size of 0.85, while atomoxetine has an effect size of 0.4. Of those that are not approved for adult ADHD, immediate-release stimulants as a group have an effect size of 0.9, long-acting stimulants have an effect size of 0.95, and nonstimulants have an effect size of 0.62.

In comparison, selective serotonin reuptake inhibitors for the treatment of OCD or MDD have an effect size of 0.5, atypical antipsychotics for the treatment of schizophrenia have an effect size of 0.25, and antidepressants for the treatment of GAD have an effect size of 0.39.

"On this basis, I would tell you that stimulant medications are the most effective psychotropic medication you have for any psychiatric disorder, hands down," he concluded.

This information concerns uses that have not been approved by the Food and Drug Administration.

By Nancy Stanley

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