Definition

Attention-Deficit/Hyperactivity Disorder (ADHD) is characterized by inattention and/or hyperactivity-impulsivity.

Attention-Deficit/Hyperactivity Disorder (ADHD) is the most common cognitive and behavioral disorder diagnosed in school-age children [American Academy of Pediatrics (AAP), 2000]. Additional school expenditures on behalf of students with ADHD exceed $3 billion a year, according to the National Institutes of Health [NIH, 1998]. The need for recognition and treatment of patients with ADHD is necessary because of an increased risk of those with unrecognized ADHD for persistent patterns of functional problems at home, in school, and/or at work; and because there can be beneficial responses to medication, i.e., stimulants, which was first reported in 1937, but therapeutically neglected for decades.

The definition and diagnostic criteria of ADHD have undergone significant changes over the past century and will continue to evolve [Spencer, 2002; Wender et al, 2001]. Spencer included a sampling of seminal citations from the medical literature starting with a publication by George Still in The Lancet in 1902 about a group of children with "abnormal defect in moral control." Spencer's article also cites the serendipitous use of amphetamines in the 1930s and subsequent clinical abandonment of stimulants until the 1960s. These and other articles on changing nosology shed interesting light on the persistent controversies about the nature of ADHD and the medication of children with behavioral problems.

Two of the most notable changes since publication in 1978 of the second edition of the Diagnostic and Statistical Manual of Mental Disorders of the American Psychiatric Association (DSM-II) are the recognition of a predominantly inattentive type of ADHD and the persistence of ADHD manifestations into adulthood [Wender et al, 2001; Wilens et al, 2002]. The preface to the popular book, Driven To Distraction, written by two psychiatrists with ADHD, describes the syndrome of ADHD as "attention inconsistency" rather than deficit because most people with ADHD can also hyperfocus at times [Hallowell and Ratay, 1994].

ADHD is no longer considered only a school-age disorder characterized by easily observable hyperactivity that typically remits during adolescence. There is robust evidence, from a variety of studies, that supports the validity of ADHD in adults [Faraone et al, 2000; Wender et al, 2001]. Considerable scientific knowledge and expert consensus now support the premise that ADHD also has a subtle presentation of inattentiveness and excessive daydreaming without overt hyperactivity. This subtle presentation is more commonly seen in females and is often unrecognized [Biederman et al 2002; International Consensus Statement (ICS), 2002; Hallowell and Ratay, 1994; Quinn and Nadeau, 2002; Wolf and Wasserstein, 2001]. Also, research studies have shown that some people with ADHD may have observable differences in CNS metabolism, neuropsychological test results, and neuroanatomic structure [Faraone et al, 2000; Wilens et al 2002; Solanto, 2002; Giedd et al, 2001; Comings, 2001; Wolf and Wasserstein, 2001].

Classification

The DSM-IV (1994) recognizes three major different subtypes of ADHD: predominantly inattentive subtype, predominantly hyperactive-impulsive subtype, and combined inattentive/hyperactive-impulsive subtype. DSM-IV states that symptoms must persist for at least 6 months and that they must be present before age 7 years for the diagnosis to be made. In addition, the symptoms must be severe enough to be considered maladaptive, be inconsistent with the patient's level of development, and not be exclusively due to another condition. Some impairment must be present in at least two settings (i.e., school, home, or work).

Predominantly inattentive subtype
Characterized by often failing to pay attention to details, making careless mistakes, not seeming to listen, having difficulty with sustained attention, disorganization, losing important things (e.g., homework assignments), and forgetfulness.
Predominantly hyperactive-impulsive subtype
Characterized by excessive fidgeting and squirming, restlessness, difficulty waiting or walking slowly, frequently interrupting and intruding upon others.
Combined inattentive/hyperactive-impulsive
Both subtypes apply for at least 6 months in two areas of life to a degree that is causing observable dysfunction in at least one area of life.

ADHD in Adults

The recognition of persistence of ADHD from childhood and diagnosis and treatment of adults is increasing among clinicians and patients [Faraone et al, 2000; Wender et al, 2001; Wilens et al, 2002]. Sometimes learning about ADHD in a child leads to recognition of similar manifestations and diagnosis of ADHD in a parent.

In adults, the core ADHD features of inattention, impulsivity, and hyperactivity present differently than in children. There may be problems with occupational performance and frequent job changes, anxiety, distractibility, marital stability, self-discipline, organization and executive function, and chronic feelings of restlessness. There is usually less overt motor hyperactivity [Searight et al, 2000; Wasserstein and Lynn, 2001; Wender et al, 2001; Wilens et al, 2002; Wolf and Wasserstein, 2001].

Sleep disturbances, e.g., insomnia, and arousal disorders, e.g., maintaining adequate alertness, are more prevalent in adult ADHD. This may be related to the underlying pathophysiology of ADHD, co-morbidities (including sleep apnea, substance abuse), lifestyle, and/or from adverse effects of medications. Sleep disorders in both genders and/or estrogenic fluctuations in females may exacerbate various dysfunctional behavior, e.g., inattention, moodiness, and tardiness to school and work [Brown and McMullen, 2001; Quinn and Nadeau, 2002].

References

American Academy of Pediatrics. Clinical Practice Guideline: Diagnosis and evaluation of the child with attention-deficit/hyperactivity disorder (AC0002). Pediatrics. 2000; 105 (5): 1158-1170.

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th ed. (DSM-IV) Washington, DC: American Psychiatric Association, 1994:83-85.

Biederman J, Mick E, Faraone SV et al. Influence of gender on attention deficit hyperactivity disorder in children referred to a psychiatric clinic. Amer J Psychiatry. 2002; 159: 36-42.

Brown TE, McMullen WJ. Attention deficit disorders and sleep/arousal disturbance. Annals of the New York Academy of Sciences 2001; 931:271-286.

Comings DE. Clinical and molecular genetics of ADHD and Tourette Syndrome. Annals of the New York Academy of Sciences. 2001; 931:50-83

Faraone SV, Biederman J, Spencer T et al. Attention-deficit/hyperactivity disorder in adults: an overview. Biol Psychiatry. 2000; 48: 9-20.

Giedd JN, Blumenthal J, Molloy E et al. Brain imaging of attention deficit/hyperactivity disorder. Annals of the New York Academy of Sciences. 2001; 931: 33-49.

Hallowell E and Ratay JJ. Driven to Distraction. New York, NY: Pantheon Books; 1994.

International Consensus Statement on ADHD (January 2002). Clinical Child and Family Psychology Review 2002; 5:89-111.

NIH Consensus Statement # 110. Diagnosis and treatment of attention deficit hyperactivity disorder. Online 1998 Nov 16-18;16(2): 1-37.

Quinn PQ and Nadeau KG. Gender Issues and AD/HD: Research, Diagnosis and Treatment. Silver Spring, MD: Advantage Books, 2002.

Searight HR, Burke JM, and Rottnek F. Adult ADHD: Evaluation and treatment in family medicine. Amer Fam Phys. 2000; 62:2077-2086.

Solanto MV. Dopamine dysfunction in AD/HD: integrating clinical and basic neuroscience research. Behavioural Brain Research 2002. 130:65-71.

Spencer TJ. Attention-deficit/hyperactivity disorder. Arch Neurol. 2002; 59: 314-316.

Wasserstein J and Lynn A, 2001. Metacognitive remediation in adult ADHD: treating executive function deficits via executive functions. Annals of the New York Academy of Sciences. 2001; 931: 376-384.

Wender PH, Wolf LE, Wasserstein J. Adults with ADHD: an overview. Annals of the New York Academy of Sciences. 2001; 931: 1-16.

Wilens TE, Biederman J, and Spencer TJ. Attention deficit/hyperactivity disorder across the lifespan. Annual Review of Medicine. 2002; 53: 113-131.

Wolf LE and Wasserstein J. Adults ADHD: concluding thoughts. Annals of the New York Academy of Sciences. 2001; 931: 396-408.

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