ADHD--Overcoming the Specter of Overdiagnosis

Few topics have generated as much public concern as the diagnosis of attention-deficit/hyperactivity disorder (ADHD). According to data from the Centers for Disease Control and Prevention, outpatient visits for ADHD jumped from 1.6 million to 4.2 million per year from 1990 to 1993. More than 70% of those patients walked away with a prescription for Ritalin (methylphenidate).

During the past decade, a growing body of research has reported that stimulant medications such as dextroamphetamine (Dexedrine, Adderall) and methylphenidate (Concerta, Methylin, Metadate) are safe and effective for treating ADHD. And the number of patients with ADHD continued to grow in the waiting rooms of pediatricians and family practitioners. Still, negative perceptions about ADHD diagnosis and treatment have been slow to change. This may be partially due to media outlets that raised alarms throughout the 1990s and 2000s about overdiagnosis and the dangers of treating children and adolescents with stimulants, which are schedule II drugs.

"I think there's a lot of public discomfort about kids being on medication," said Craig L. Donnelly, M.D., director of pediatric psychopharmacology at Dartmouth-Hitchcock Medical Center.

Psychiatrists have not done the best job of getting the message out that ADHD is a medical disorder that leads to significant dysfunctions that can be effectively treated, Donnelly told Psychiatric Times.

In Connecticut, fear of teachers pushing medications on children was strong enough to influence legislation. Since July 2001, school personnel are prohibited from recommending the use of psychotropic drugs for any child. The law applies to all written and oral communications and affects nurses, guidance counselors, mental health care professionals and social workers.

"I think that's clearly overkill," Donnelly said. He added that, by and large, teachers have experience with children and are able to correctly identify problem behaviors. But there's a perception among some parents that teachers want children medicated simply so they will behave in the classroom.

While the public concerns itself with overprescription, about half of children with ADHD go without treatment in a given year. "Most of our research indicates that it's probably both over- and underdiagnosed," David Fassler, M.D., told PT. Fassler is past chair of the American Psychiatric Association's Council on Children, Adolescents and their Families.

The key is an accurate diagnosis, said Fassler, who practices child and adolescent psychiatry in Burlington, Vt. The only way to achieve an accurate diagnosis is through a comprehensive assessment by a mental health care professional with expertise in ADHD.

There are cases when problematic behaviors have resulted in parents being encouraged or pushed into getting their child evaluated and treated, Donnelly said. Often the cause of the misbehavior or academic problems is not ADHD, but a learning disability, anxiety disorder or depression. This underscores the need for a thorough, comprehensive psychiatric evaluation.

While there is no blood test or brain scan for identifying ADHD, researchers have found that a thorough assessment using the DSM-IV criteria can accurately diagnose the disorder, said Christopher Kratochvil, M.D., assistant director of the Psychopharmacology Research Center at University of Nebraska Medical Center.

"With a thorough assessment, the reliability of the diagnosis is very high," Kratochvil told PT. "If you ask two independent clinicians to examine the same child, they will quite reliably reach the same diagnostic conclusion."

But in places like Nebraska, finding a clinician with that kind of training can be hard to come by. The state only has 18 child and adolescent psychiatrists. Historically, adult psychiatrists have not been trained in diagnosing and treating ADHD, Kratochvil said, and, for the most part, primary care physicians have not had significant training in this area either.

Scope of the Disorder

Attention-deficit/hyperactivity disorder is the most commonly diagnosed childhood behavioral disorder. Researchers estimate that ADHD affects 3% to 5% of school-age children in the United States. It accounts for 30% to 50% of child referrals to mental health services.

According to the DSM-IV, ADHD has 18 core symptoms. Nine are related to inattention and nine are related to hyperactivity and impulsivity. Children with inattentive symptoms are less likely to be identified as having the disorder, since they usually sit quietly in the classroom. This may be the case with girls with ADHD who may tend to be less disruptive in school settings and less likely to be identified and referred for evaluation and treatment. Fassler speculated that this could explain why there is a perception that ADHD occurs mostly in boys.

Research has shown that genetic factors play a major role in ADHD. It is the only psychiatric disorder so far for which identification of candidate genes has been replicated. Functional magnetic resonance imaging also has helped shed light on the disorder.

Only 31% of children with ADHD have no co-occurring disorders. According to the Multimodal Treatment Study of Children with ADHD (Arch Gen Psychiatry 1999;56[12]:1073-1086):

• 39.9% have oppositional defiant disorder;
  
• 37.3% have an anxiety or mood disorder;
  
• 14.3% have a conduct disorder;
  
• 10.9% have a tic disorder.
  

Most children who are diagnosed and treated for ADHD never see a psychiatrist. This can be a problem, as the American Academy of Child and Adolescent Psychiatry (AACAP) says it should take several hours to do a full evaluation.

"The reality of pediatric practice is that you rarely have the time necessary to permit a full evaluation of these kinds of complex disorders," Fassler said. "It's not an evaluation you can realistically do in 10 to 15 minutes."

In order to make an accurate diagnosis, the clinician needs to determine how the child is doing at home, at school and with peers. The child's medical history must be examined, and time needs to be spent with both the child and the family. Without a thorough assessment, there's a risk that depression, anxiety or bipolar disorder is being misdiagnosed.

"As our knowledge base improves, hopefully this will become less of a problem," Fassler said.

He emphasized that children with ADHD and other psychiatric conditions need to be treated as early as possible. Their symptoms are disruptive to child development, creating problems at school, at home and among peers.

Children with untreated ADHD usually engage in disruptive behaviors that ultimately result in rejection from their peer group. Adolescents and young adults with untreated ADHD have high rates of comorbid substance abuse disorders. A 1999 study appearing in Pediatrics found that boys with ADHD who were not treated with medication were significantly more likely to abuse drugs than were boys who received treatment (1999;104[2]:e20). The risk of substance abuse for boys who took medication was virtually identical to the risk for boys without ADHD.

Fassler emphasized that there have been hundreds of studies showing the safety and efficacy of stimulant medications for ADHD. And research shows that the biggest risk for substance abuse is to leave the ADHD untreated.

Clearly if a person takes enough stimulant medication, they will get a buzz, Donnelly said. But at therapeutic dose levels, there should not be a perceived buzz or euphoric effect. In the doses used for clinical treatment of ADHD, stimulant medications are nonaddicting, he said. The prescribing physician does not have to keep upping the dose to achieve the desired results, and children being treated do not crave the medication.

Attention-deficit/hyperactivity disorder is chronic, and more than 40% to 50% of affected children will have symptoms that persist into adulthood. Studies indicate that problems with substance abuse, academic or employment failures, and antisocial behaviors may persist into adulthood in people with untreated ADHD.

Donnelly predicts that adults with ADHD will receive more attention over the next few years. Psychiatrists have been hesitant to diagnose ADHD in adults, he said, and the DSM-IV criteria are oriented toward children's behavior. But as more and more children now diagnosed with ADHD carry their symptoms into adulthood, it will become an area of more intense clinical and research interest.

• Bridging the Gap

Psychiatrists are now focusing on ways to enhance their consultation with pediatricians and primary care physicians. "There'll never be enough psychiatrists to see all children with psychiatric disorders, and not all children with psychiatric disorders need to be seen by psychiatrists," Fassler said. "But we need to get better at working collaboratively with our colleagues."

Experts also need to do a better job of broadcasting the message that there are valid, effective, easy-to-use instruments for tracking ADHD symptoms and treatment, Donnelly said. In treating ADHD, practitioners need to take a team approach and develop a working alliance with parents and schools. Adequate feedback from observers across the different domains of a child's functioning are important for optimizing treatment.

Psychiatrists need to work with payers to ensure that adequate reimbursement is received for comprehensive assessments, Fassler said. "A good evaluation and consultation is such a cost-effective intervention that I think we need to advocate with third-party payers to improve access to such services."

So many of these children will be receiving services for such a long time that it's critical to make sure that clinicians have a full understanding of the nature of a child's problem from the start, he said.

National organizations such as the AACAP and the American Academy of Pediatrics have made training materials available. According to Fassler, physicians and payers have started to develop innovative models to facilitate consultation on the local level.