Prevalence of ADHD

ADHD is a worldwide disorder. Estimates for ADHD prevalence worldwide vary from 1.5% to almost 20%J1-6 The prevalence of ADHD in the United States is estimated by the U.S. Centers for Disease Control and Prevention (CDC) to be 7.74% of all school age children (about 4.4 million children). A recently published study (2007) determined that almost 9% of all U.S. children suffer from ADHDJ8 It is not known why the range of prevalences reported vary as much as they do. They may be because of actual differences or variations in diagnosis and data collection. 

ADHD is not just limited to children. It has been estimated that 4.4% of adults aged 18-44 in the United States experience symptoms and some disability. U°1 

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Although most experts believe the prevalence of ADHD in the United States to be between 3 and 5% of the population, ARCOS data, prescription data, and epidemiological studies have identified large differences between communities. Some areas... 

In conclusion, the strong prevalence of ADHD in children whose iodine-deficient mothers had experienced... 

Faraone S. V., Sergeant J., Gillbeig C. and Biederman J. 2(XB. The worldwide prevalence of ADHD Is it an American condition World Psychiatr. 2 104-113... 

Although ADHD generally is considered a childhood disorder, symptoms can persist into adolescence and adulthood. The prevalence of adulthood ADHD is estimated to be 4%, with 60% of adults having manifested symptoms of ADHD from childhood.8,9 Further, problems associated with ADHD (e.g., social, marital, academic, career, anxiety, depression, smoking, and substance-abuse problems) increase with the transition of patients into adulthood. 

There are reports of an association between low fish consumption and increased prevalence of depression (Hibbelin, 1998). Some studies have found a reduced level of omega-3 fatty acids in depressed patients. It has also been speculated that EFAs have a role in the causation of schizophrenia and, more recently, ADHD and behavioral problems (Stevens et ah, 1996 Burgess et ah, 2000). 

Murphy, K. and Barkley, R. (1996) Prevalence of DSM-IV symptoms of ADHD in adult licensed drivers implications for clinical diagnosis. J Attention Disord 1 147-161. 

One more recent study describing the prevalence of polypharmacy within a specific population was conducted by Zarin and colleages (1998a). These authors surveyed 65 psychiatrists who were treating children or adolescents under the age of 15 years with a diagnosis of ADHD, and found that 37% and 12% of psychiatrists treated their patient with two versus three or more psychotropic medications, respectively, at the time of the index visit. Specifically, 39% of the psychiatrists prescribed a stimulant medication in combination with a nonstimulant medication. 

The reasons for medication and the way in which it tends to be used may also vary as a function of local factors. For example, LeFever et al. (1999) surveyed the prevalence of drug administration by school nurses to public school students with ADHD, grades 2... 

The likelihood of males more frequently being prescribed medication, at least for ADHD, is not a simple function of the greater prevalence of the disorder... 

These criteria result in a much lower prevalence of hyperkinetic disorder, with estimates in the range of 1-5%, as compared to 5-10% in school-aged children for ADHD. In the ICD-10 there is a lower possibility of diagnosing children with attention deficit without hyperactivity. In the ICD-10 another diagnosis of other specified behavioral and emotional disorders with onset usually occurring in childhood and adolescence must be used. However, the combined condition of hyperkinetic disorder and conduct disorder is delineated under the diagnosis hyperkinetic conduct disorder. ... 

The prevalent theory among both health professionals and the general public today is that the symptoms of ADHD have a biological cause. The most generally cited causes are birth defects, an infant trauma, and the brain s inability to produce enough of specific neurotransmitters, or brain chemical messengers. 

The diagnosis of ADHD frequently occurs when other disruptive behavior disorders are diagnosed. As in many other diagnoses in pediatric psychiatry, the ambiguities involved in ADHD diagnosis mean that estimates of prevalence are loose at best. The high end of prevalence estimates is 10 percent, the low end 3 percent. 

A word about prevalence mental illness is more common than many people imagine. The current prevalence estimates are that about half the U.S. population meets the criteria for at least one mental disorder during a lifetime, with about 25 percent of the population meeting the criteria for at least one mental disorder during any given year.1 Of these disorders, the most prevalent are apparently anxiety disorders, followed by mood disorders (for example, major depressive disorder), impulse-control disorders (for example, attention deficit hyperactivity disorder [ADHD]), and substance disorders (for example, alcohol abuse). In contrast, the prevalence of psychosis as I define it here is only 2—3 percent of the U.S. population, and the world prevalence is about the same. 

A high prevalence (68.7%) of ADHD is reported here in children Hving in a mild-to-moderate ID areas. ID-related ADHD affects intelligence. Indeed, the total IQ score of ADHD children was 22 points lower compared to control children from an iodine-sufficient area. 

The ADHD prevalence of almost 90% in children born to hypothyroxinemic mothers seems to point to a strong association of this neuropsychological disorder with ID-related early gestational maternal hypothyroxinemia. 

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