Diagnosis

The diagnosis of ADHD is a clinical one that is primarily based on a detailed history. The features that a patient exhibits — specifically the symptoms and the signs noted on examination — can help to support the diagnosis, but ADHD is primarily a clinical diagnosis.

Clinical Features

Teenagers and adults with ADHD are at increased risk for engaging in unsafe behaviors, including conflict with authority figures, smoking, substance abuse (in adulthood), speeding while driving, and delinquency. Substance abusers with ADHD tend to prefer other drugs over alcohol and may have greater persistence of substance abuse. Children with ADHD who are treated with stimulants (i.e., methylphenidate) are less likely to be substance abusers than children with ADHD not treated with stimulants.

Understanding ADHD and associated vulnerabilities is important for those who have ADHD and those who interact closely with them. Appropriate intervention and understanding help compensate for decreased "working memory" and some other deficits. Although manifestations of ADHD are typically present before age 7 and may cause lifelong dysfunction, delayed or missed diagnoses are not unusual [AAP, 2000; Biederman et al, 1999; Faraone and Doyle, 2001; Wilens et al, 2002; Wender et al, 2001].

Adults with ADHD often suffer from lack of organization, frustration, and feelings of failure. The frustration comes from awareness of a gap between their potential and repeated sub-optimal outcomes. Many adults with ADHD have been misdiagnosed, and/or treated with inappropriate medications and psychotherapies. Many are creative and visionary and have found partners who have areas of strength and skills that compensate for their own areas of deficiency [Hallowell and Ratay, 1994].

Family dynamics tend to reflect greater disorganization when at least one parent and child have ADHD. At least 25% of children with ADHD have a parent who also has ADHD. More than 50% of adults with ADHD have at least one child with ADHD. It is not unusual for the proper diagnosis in a child to lead to identification of ADHD (or another psychiatric diagnosis) in a parent and/or siblings [Wolf and Wasserstein, 2001].

Defective "executive function" or self-awareness and regulation is postulated by some clinicians to be of major significance in adults [Reviewed by Faraone et al, 2000]. For example, a common problematic pattern in executive function involves poor organization, lack of planning, and boredom following a consistent routine. Poor self-regulation results in easy distractibility at work or responding without inhibition to internal or external stimuli rather than more resourceful use of internalized principles, proactive plans, or prior commitments.

Differential Diagnosis

Three practical articles on evaluating and treating ADHD by primary care physicians have been published in the American Family Physician [Searight et al, 2000; Smucker and Hedayat, 2001; Szymanski and Zolotor, 2001]. Below are a number of conditions commonly associated with ADHD which should be ruled out before a definitive diagnosis of ADHD can be made.

Medical conditions: impairment of hearing and/or vision, adverse drug event, asthma, allergic rhinitis (or reaction to antihistamine), incontinence of urine or feces, malnutrition (vitamin or metabolic deficiency), thyroid disorder, and lead toxicity.
Neurologic and psychiatric conditions: learning disorder, tic disorder, seizure disorder (or effect of antiepileptic), mental retardation, developmental delay, brain damage or injury, sleep disorders (including sleep apnea and insomnia), oppositional defiance and conduct disorders, substance abuse, anxiety, depression (or bipolar disorder), obsessive-compulsive disorder, and post-traumatic stress disorder.
Environmental conditions: improper or poor learning environment, mismatched curriculum and child (gifted, learning disabled, language issues), dysfunctional family or stressful home, poor parenting (inconsistent, punitive), neglect or abuse, and parental psychopathology.

Results of routine laboratory tests are usually normal and are, therefore, only useful in screening for associated conditions and for establishing a baseline for monitoring therapy.

DSM-IV Criteria for ADHD

According to the DSM-IV criteria for diagnosing ADHD, at least 6 of 9 inattentive symptoms or at least 6 of any combination of 6 hyperactivity and 3 impulsivity symptoms must have persisted for six months, are maladaptive, and not due to developmental level.

Some of these symptoms that have caused impairment must have been present before age 7 years. There must be some impairment present in at least 2 settings (e.g., school, work, home) along with clear evidence of significant impairment in social, educational, or work-related functioning. Finally, these symptoms must not be caused exclusively by a pervasive developmental or other mental disorder (e.g., personality or anxiety disorder).

ADHD in Children

The Consensus Statement of the National Institutes of Health (NIH) issued in November 1998 stated, "The diagnosis of ADHD can be made reliably using well-tested diagnostic interview methods. However, as of yet, there is no independent valid test for ADHD" [NIH, 1998].

ADHD manifestations begin in childhood. Proper diagnosis should include evaluation for other causes of behavioral problems but not exclude co-occurring conditions [DSM-IV, 1994]. Szymanski and Solotor [2001] have provided concise diagnostic recommendations for assessment of possible ADHD as well as information about behavioral check lists designed for children.

The most widely accepted diagnostic criteria for ADHD are those in the DSM-IV (314.00, 314.01, 314.9) [1994]. The Clinical Practice guidelines of the American Academy of Pediatrics (AAP) issued in 2000 note, however, "... it is important to recognize the limitations of the DSM-IV definition. Most of the development and testing of the DSM-IV has occurred through studies of children seen in psychiatric settings. Much less is known about its use in other populations, such as those seen in general pediatric or family practice settings."

Despite the agreement of many professionals working in this field, the DSM-IV criteria remain a consensus without clear empirical data supporting the number of items required for the diagnosis. Current criteria do not take into account gender differences or developmental variations in behavior. Furthermore, the behavioral characteristics specified in the DSM-IV, despite efforts to standardize them, remain subjective and may be interpreted differently by different observers.

Continuing research will likely clarify the validity of the DSM-IV criteria (and subjective modifications) in the diagnosis. These complexities in the diagnosis mean that clinicians using the DSM-IV criteria must apply them in the context of their own clinical judgement." The AAP guideline also contains a useful clinical algorithm for diagnosis, evaluation, and treatment of children with suspected ADHD [AAP, 2000].

ADHD in Adults

There are no adult-specific diagnostic criteria in the DSM-IV [Wilens et al, 2002]. A formal diagnosis, using DSM-IV standards, may be made by retroactively applying DSM-IV standards to childhood, excluding other disorders and/or diagnosing co-morbid conditions, and looking for pervasiveness and persistence of ADHD manifestations into adulthood. ADHD in partial remission is a term sometimes used for adults who have some of the symptoms that were present during childhood. Useful information may be obtained by reviewing school records or interviewing parents, if available, for evidence of childhood problems and ADHD symptoms.

Alternatively, a Parents' Rating Scale (PRS), based on the Connors Rating Scale used for ADHD assessment in children, may be used. The PRS has 10 items which the parent uses to rate the patient as if a child between the ages of six and 10 years. Several rating scales have been developed for use in adults. A critical examination of gender bias in the diagnosis of ADHD and a newer Self-Assessment Symptom Inventory for Women has recently been published [Quinn and Nadeau, 2002]. One of the most researched rating scales for hyperactive/impulsive ADHD in adults is the 61-item Wender Utah Rating Scale (WURS). The WURS includes childhood characteristics that go beyond minimally meeting the DSM-IV criteria, plus specific adult characteristics. Other rating scales include those associated with Tom Brown and Copeland [Brown et al, 2001; Searight et al, 2000; Wender et al, 2001].

A comprehensive and multifaceted overview that summarizes evidence for the validity of ADHD in adults has been published by an authoritative group affiliated with Harvard Medical School. It is recommended reading for those who want a further understanding of the complex issues involved in establishing the diagnosis of ADHD in adults, as well as the diagnostic continuity and developmental evolution of ADHD from childhood to adulthood [Faraone et al, 2000].

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 and Spencer T. Attention-deficit/hyperactivity disorder (ADHD) as a noradrenergic disorder. Biological Psychiatry. 1999; 46:1234-1242.

Brown RT, Freeman WS, Perrin JM et al. Prevalence and assessment of attention-deficit/hyperactivity disorder in primary care settings. Pediatrics. 2001; 107 (3): e43.

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

Faraone SV, Doyle AE. The nature and heritability of attention-deficit/hyperactivity disorder. Child and Adolescent Psychiatric Clinics of North America. 2001; 10 (2):299-316.

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

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.

Smucker WD and Hedayat M. Evaluation and treatment of ADHD. Amer Fam Phys. 2001; 64;817-829.

Szymanski ML, Zolotor A. Attention-deficit/hyperactivity disorder: management. Amer Fam Phys. 2001; 64:1355-1362.

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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