Is ADHD a real medical condition that justifies treatment with medication? The popular media quite also describe it as a questionable diagnosis, or overdiagnosed, or treated with unnecessary medication. Critics suggest the symptoms of hyperactivity, inattention, and impulsivity are merely extreme variations of normal human traits. Their criticism further attributes the cause to over demanding parents, poor teachers skills, and an over competitive society.
In scientific literature the majority view ADHD as a valid and common psychiatric disorder of childhood. A set of criteria for establishing in a psychiatric condition as a valid psychiatric disorder was established by Robins and Guze in 1970. This became the framework for how all diagnoses get included in the American Psychiatric Association’s diagnostic manual. These criteria all require that scientific studies have had been done and support every one of the six criteria.
Following are the six criteria required to make a classification of a cluster of signs and symptoms as a valid psychiatric condition:
1. CLINICAL CORRELATES
“A valid diagnosis needs to be reliably identified through a consistent pattern of signs and symptoms demarcating it from other disorders and from psychiatric wellness.”
This means that if a group of doctors independently evaluated the same group of patients and use the same test to diagnose the patients, there is high agreement as to which patients did have the disorder and which did not have ADHD. Numerous scientific studies have established the high reliability of different rating scales for the diagnosis of ADHD.
Also, a diagnosis of a condition cannot be made if the symptoms of that condition do not cause significant impairments. Studies have documented inferior academic performance, reduced social skills, inattention in the duration of focus on a single task, impulsivity disrupting schoolwork, and hyperactivity causing fidgeting and talking excessively. Impairments continue into adolescence with high rates of delinquency, more arrests, and higher risk of substance abuse disorders. Other studies document higher rates of injury, cycling injuries, and pedestrian injuries. Driving performance impairment leads to higher accident rates and traffic citations.
2. DELIMITATION FROM OTHER DISORDERS
This means that ADHD is a condition that is separate from other diagnoses. It isn’t a cluster of signs and symptoms and impairments that is actually part of another diagnosis. Symptoms of major depression, generalized anxiety, and bipolar disorder often include symptoms that overlap with ADHD. For example, hyperactivity and reduced concentration are common in major depression. However, when patients that are diagnosed with major depression and ADHD have the symptoms that are part of major depression subtracted from their ADHD diagnosis, the majority of these dual diagnosed patients still meet the criteria for ADHD. Also, when the symptoms of ADHD were removed from patients with a dual diagnosis that included major depression, most of them still met the criteria for major depression.
This overlapping or comorbid occurrence of two or more psychiatric diagnoses in an individual is common. Interestingly, when family studies are done, some conditions such as ADHD and depression tend to run together in families. Other conditions as anxiety disorders and ADHD run independent of each other.
Impairments and other negative consequences in ADHD patients cannot be all explained away by coexisting conditions of conduct disorder, major depression, and learning disabilities. For example, rates of arrest, drug abuse, and executive dysfunction are elevated in ADHD. These problems are further elevated it conduct disorder is also present.
3. COURSE AND OUTCOME
A valid psychiatric disorder needs to have a characteristic course and outcome. Long-term studies showed childhood ADHD is a chronic disorder that survived into adulthood in a significant number of patients. While many fail to meet the full strict criteria for the condition in adulthood, 90% retained significant symptoms to have persistent significant clinical impairments. Numerous studies report that ADHD has a natural course that provides another method ofdelimiting it from other disorders. For example, if symptoms of ADHD occur intermittently along with episodes of another disorder, this would not be viewed as evidence of ADHD because of lack of chronic persistence of symptoms.
4. EVIDENCE FOR HERITABILITY FROM FAMILY AND GENETIC STUDIES
ADHD meets the criteria for being a scientifically based disorder on neurologic grounds of being heritable. Numerous family studies and genetic studies provide evidence.
Family studies found parents and siblings of ADHD children have a 2-8 fold increased risk of being ADHD. All 15 twin studies showed increased risk in the twin of an ADHD child. The risk was 75% for familial status of having ADHD. Consequently, only 25% of this is due to environmental factors. The studies came from families from around the world (US, UK, Australia and Sweden). Studies from all of these countries are in agreement that there is an inherited risk for ADHD.
Adoption studies provide further evidence of the genetic influence on risks for ADHD. Biologic relatives of ADHD children have higher rates of ADHD than adopted relatives.
Molecular genetics studies found strong association between several neurotransmitter genes and ADHD. These neurotransmitters are dopamine, norepinephrine, and serotonin. They are implicated in causing ADHD and are involved in the therapeutic effects of ADHD medications.
5. LABORATORY STUDIES
Another method of developing evidence to support a neurobiological connection of ADHD diagnoses is laboratory studies. PET scan studies found evidence of defective dopamine transporter function in the striatal region of the brain of ADHD patients. These were performed on live patients with real-time images of metabolic activity. Scientifically controlled studies of the physical structure of brain of ADHD patients compared to normal found evidence of abnormal structures in parts of the brain. Ten controlled studies of brain function found abnormalities in multiple areas of the brain of ADHD patients. While the particular parts of the brain were not consistently involved in the different ADHD patients, the findings were consistent with their knowledge of brain pathways and systems involved in the regulation of complex behaviors that may be involved in the motor control, in attention, and executive function deficits seen in ADHD.
6. TREATMENT RESPONSE
The validity of a diagnosis is bolstered if patients with a defined condition respond to a particular medication treatment. Many controlled studies provide evidence of the high rate of treatment response of methylphenidate in reducing overactivity, impulsiveness, and inattentiveness. In addition to improving ADHD symptoms, many studies provide strong evidence of the medication effectiveness in reducing ADHD-related impairments in children and adults. Other medications besides stimulants have been proven to be effective in ADHD patients. These include tricyclics and atomoxetine(Strattera). All of these medications have been shown to block norepinephrine and/or dopamine reuptake at receptor site. While this data provides additional evidence of the validity of the ADHD diagnosis, they do not mean that this treatment response should be used as a method to make the diagnosis. Stimulant medications can improve cognition and attention in non-ADHD individuals just as high blood pressure medicine may reduce blood pressure in people with normal blood pressure .
Numerous studies provide enough evidence that ADHD meets the six criteria of Robinson and Guze standard criteria:
1) ADHD patients show a characteristic pattern of hyperactivity, inattention, and impulsivity that lead to adverse outcomes.
2) ADHD can be distinguished from other psychiatric disorders including those with which it is frequently comorbid.
3) Longitudinal studies show ADHD is not an episodic disorder. It is always chronic and sometimes remits in adolescence or adulthood.
4) Twin studies show ADHD is a highly heritable disorder, as heritable as schizophrenia or bipolar disorder. And molecular genetic studies have discovered genes that explain some of the disorder’s genetic transmission.
5) Neuroimaging studies show that ADHD patients have abnormalities in the motor control frontal-cortical-cerebellar pathways involved in the control of attention, inhibition, and motor behavior.
6) Most ADHD patients show a therapeutic response to medications that block the dopamine or norepinephrine transporter.
One concern is that most studies have been done with the most severe examples of ADHD who are referred to doctors and clinics.Thus, the studied populations may not represent the whole spectrum of severity of symptoms and impairments. Therefore, it would not be valid to generalize the facts about these patients to nonreferred ADHD patients in the community. However, two of the criteria for the diagnosis of ADHD are based on wide population studies. (1) Several epidemiologic studies have been supportive because they found the clinical features of ADHD in these community population samples. (2) and several studies were done with population samples demonstrating the high heritability of ADHD in cases that are not necessarily the most severe cases.
Another group of critics argue that ADHD signs and symptoms are better viewed as a normal continuous varying spectrum of traits rather than a disorder. The problem with this argument is that even normal variation can be a disorder if the more extreme cases suffer distress or disability. An example is how the normal variations of blood pressure and serum cholesterol level become medically urgent disorders in the more extreme levels.
Other critics argue that because there is not 100% agreement of results among different studies, a diagnosis is not valid. However, the preponderance of the evidence is overwhelmingly supports that ADHD is a valid diagnosis, especially when careful reviews of the different studies and meta-analysis studies were done.
Some critics hold the opinion that ADHD impairments are due to a highly competitive society, failure of parenting and teaching, or societal intolerance of extreme but normal symptoms. However, the genetic and neurobiological evidence is too strong to totally discount. There obviously are environmental factors that contribute to whether or not a person develops ADHD. There Is much evidence that ADHD’s causes are multifactorial, caused by the addition and interplay of genes and environmental risk factors.
Parents and patients with ADHD often have misgivings about accepting help and medication for ADHD. When they encounter misunderstanding about the diagnostic validity of ADHD, their resistance grows. Corrective education from medical and mental-health professionals may be the first step in helping distressed ADHD patients to get help that will bring them relief and success in their lives.
Written by Dr. Darvin Hege, M.D. on January 8, 2010 with content drawn heavily from the following article:
The scientific foundation for understanding attention-deficit/hyperactivity disorder as a valid psychiatric disorder. Faraone SV. Department of Psychiatry, SUNY Upstate Medical University, Syracuse, NY 13210, USA. firstname.lastname@example.org
Dr. Darvin Hege has 25 years of experience dealing with patients who may fit the criteria for ADHD and may need a medication like Adderall for ADHD. He offers evening and weekend office hours at his Atlanta, GA practice. Call today at 770-458-0007 to discuss getting an ADHD evaluation and for help deciding the most effective and safest treatment.