Dr. Goodman is director at the Adult Attention Deficit Disorder Center of Maryland, at Johns Hopkins at Green Spring Station in Lutherville, as well as assistant professor in the Department of Psychiatry and Behavioral Sciences at Johns Hopkins University School of Medicine in Baltimore.

Disclosure: Dr. Goodman is consultant to Avacat, Clinical Global Advisors, Eli Lilly, Forest Laboratories, McNeil, New River Pharmaceuticals, Shire, and Thompson Reuters; on the speaker’s bureaus of Forest, McNeil Pediatrics, Shire, and Wyeth; receives grant support from Cephalon, Eli Lilly, Forest Laboratories, McNeil, New River Pharmaceuticals, and Shire; and receives honoraria from the American Professional Society of ADHD and Related Disorders, the Audio-Digest Foundation, CME Inc, Eli Lilly, Excerpta Medica, Forest Laboratories, JB Ashton Associates, McNeil, Medscape, the Neuroscience Education Institute, Shire, Synmed Communications, Temple University, the Veritas Institute, WebMD, and Wyeth. Funding was provided by Shire US Inc.

Acknowledgments: The author wishes to thank Lenard Adler, MD, for valuable assistance in reviewing this manuscript. Editorial assistance was provided by Robert Gregory, William Perlman, and Rosa Real, Excerpta Medica, Bridgewater, New Jersey.

Please direct all correspondence to: David W. Goodman, MD, Director, Adult Attention Deficit Disorder Center of Maryland, Johns Hopkins at Green Spring Station, 10751 Falls Road, Suite 306, Lutherville, MD 21093; Tel: 410-583-2726; Fax: 410-583-2724; E-mail: dgoodma4@jhmi.edu.


 

Focus Points

• The persistence of attention-deficit/hyperactivity disorder (ADHD) symptoms into adolescence and adulthood strongly supports the concept that ADHD is a lifelong disorder for many patients.
• The growing acknowledgment of ADHD in adults as a valid diagnosis indicates that the number of adults seeking professional attention for ADHD will increase in the years to come.
• Diagnosis of ADHD in adults may be challenging because no objective medical or neuropsychological test can be used to make or confirm the diagnosis, and there is no established consensus on the specific symptom cluster for ADHD in adults.
• Missed diagnosis and the absence of treatment of ADHD in adults can be associated with educational, occupational, and social impairments in adaptive functioning.
• The clinical evaluation and interview, essential in identifying the chronicity and pervasiveness of ADHD symptoms and associated impairments, are critical to the correct diagnosis of ADHD in adults.
• Diagnosis may be assisted through the use of several recently developed screening and diagnostic instruments for assessment of ADHD in adults, specifically those that employ adult-specific language.

 

Abstract

The prevalence of attention-deficit/hyperactivity disorder (ADHD) in adults 18–44 years of age ranges from 4.4% to 5.2%. The proportion of those adults who receive pharmacologic or nonpharmacologic treatment for ADHD is only 10.9% to 12.6%, indicating that ADHD remains undiagnosed and untreated in millions of adults in the United States. The potential consequences of ADHD in these adults include major functional impairments in education, work performance, and family and community life. Diagnosis should be based on clinical assessment using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria for ADHD. Among adults, the core ADHD symptoms of hyperactivity and impulsivity tend to diminish with age, and inattention becomes a predominant symptom domain. Many ADHD symptoms are nonspecific and overlap with other psychiatric disorders. Moreover, comorbid ADHD is common in patients with many other psychiatric disorders and comorbid disorders are evident in many adults with ADHD. This article reviews important considerations in diagnosing ADHD in adults and screening and diagnostic instruments that assist in accurate diagnosis of the disorder.

Introduction

The understanding of attention-deficit/hyperactivity disorder (ADHD) has evolved over the years, but the core symptoms of this psychiatric disorder have continued to be defined by inattentive and behavioral characteristics. In the early 20th century, Still,1 an English pediatrician, first described “defective moral control,” which comprised some symptoms similar to those in the current definition of ADHD. During the following half century, these characteristics were sometimes considered the sequelae of damage to the brain—either a head injury or a central nervous system (CNS) infection.2 When the characteristics were found in children without a history of such an insult, the damage was considered to be minimal (only manifesting as a behavioral change), giving rise to the term “minimal brain dysfunction.” This term was used to describe a cluster of symptoms that included emotional lability, abnormal electroencephalograms, motor deficits, specific learning deficits, hyperkinesis, impulsivity, and short attention span.2 Other terms used for patients’ symptoms were minimal brain damage, organic learning and behavior disorders, organic deviation, and CNS deviation.

In the Diagnostic and Statistical Manual of Mental Disorders, Second Edition, the behavioral manifestations of overactivity, restlessness, distractibility, and short attention span were described as components of a specific disorder, “hyperkinetic reaction of childhood (or adolescence).”3 This became “attention deficit disorder” in the  DSM-III,4 “attention-deficit hyperactivity disorder” in the DSM-III-R,5 and then “attention-deficit/hyperactivity disorder” in the DSM-IV and DSM-IV-TR.6,7 Since the DSM-III, the criteria have emphasized three core symptoms: inattention, impulsivity, and hyperactivity.

It was not until the DSM-III-R that ADHD in adults was included in the definition of the disorder, reporting that “Follow-up studies of clinic samples indicate that approximately one-third of children with ADHD continue to show some signs of the disorder in adulthood.”5 The criteria, however, included onset of ADHD before 7 years of age. The DSM-IV provided criteria to diagnose adults with ADHD, and noted that symptoms (particularly motor hyperactivity) attenuate during late adolescence and adulthood in most patients.6 Some patients experience all of the symptoms into mid-adulthood, while others retain only some, in which case the diagnosis is ADHD “in partial remission.” The various subtypes of ADHD are described in Table 1.7 The DSM-III included a category “attention deficit disorder, residual type” for patients in whom signs of hyperactivity are no longer present, but for whom “symptoms of inattention and impulsivity result in some impairment in social or occupational functioning.”4,8,9

 

 

 
The DSM-IV also provides a diagnosis of ADHD “not otherwise specified (NOS)” for patients whose symptoms and impairment meet the criteria for a subtype of ADHD, but whose age of onset is ≥7 years or who do not reach the threshold of six of nine symptoms for the disorder. The guidelines do not further elaborate on the concept, but Faraone and colleagues10 examined adults with both late-onset ADHD (83% had an age-of-onset between 7 and 12 years of age) and subthreshold ADHD symptoms. The late-onset subjects had a pattern suggestive of familial inheritance, comorbid disorders, and functional impairment consistent with those meeting full criteria. Those with subthreshold symptoms, however, had milder impairments and lacked the familial pattern, suggesting this might not be a valid diagnosis.

Assessments of ADHD in adults remained largely unchanged in the DSM-IV-TR published in 2000.7 As McGough and Barkley8 noted, the DSM criteria have never been validated in adults, do not include developmentally appropriate symptoms and thresholds for adults, and fail to identify some significantly impaired adults who could benefit from treatment. Clinical considerations and available instruments for assessment and diagnosis of ADHD in adults are reviewed below.

Methods

A search of PubMed was conducted to identify relevant studies and critical reviews on the assessment and diagnosis of adults with ADHD. Using the search terms “ADHD,” “adults,” and “diagnosis,” the primary criteria for inclusion in this article were that each study be controlled, had an adequate number of subjects, assessed symptoms using acceptable scales and tests, and was published during the past 20 years. Several older articles are included for historic context.

Diagnosing ADHD in Adults

The DSM-IV-TR diagnostic criteria for ADHD are listed in Table 2.7 Symptoms of ADHD may persist into adolescence in up to 30% to 80% of cases and into adulthood in up to 65% of cases.11-13 In most cases, symptoms (particularly motor hyperactivity) attenuate during late adolescence and adulthood, although some patients experience all of the symptoms of ADHD into mid-adulthood.7 The clinical evaluation and interview are essential to the diagnosis of ADHD in adults.14,15 This includes discussion regarding patient recall of any childhood symptoms of ADHD.14 Current symptoms and their impact on work, home, and social functioning should also be explored.14 Clinicians should assess the patient’s family history and observable impairments of family members, including disorganization, job/financial instability, and alcohol/substance use disorders.15 Rating scales (reviewed below) can be useful in gathering information from patients regarding childhood and current symptoms.16 If possible, a collateral interview with a family member during the assessment can provide valuable information that the patient may not self report.14 Alternatively, a family member may complete an ADHD rating scale as an observer to complement and confirm the patient’s symptom and impairment report.14 Formal records such as report cards and conduct reports are also useful.14 In addition, because the DSM-IV-TR diagnostic criteria use child-specific language, the clinician needs to extrapolate symptoms and other information to adult domains of functioning.

 

 

In addition to meeting the DSM-IV-TR cut-off scores for core symptoms of ADHD, chronicity and pervasiveness of symptoms and their role in functional impairment also need to be present.7 The DSM-IV-TR criteria for diagnosis of ADHD also include requirements for impairment in at least two settings (eg, at school or work and at home).7 Assessment of whether the symptoms occur exclusively during the course of a pervasive developmental disorder, learning disorders, or other psychiatric disorders, or can be better accounted for by another mental disorder, is also important.7

The three major subtypes of ADHD are described in the DSM-IV-TR7: the combined type (most frequently diagnosed in adults), the predominantly inattentive type, and the predominantly hyperactive-impulsive type (Table 1). As noted above, another category, ADHD-NOS, is included for disorders with prominent symptoms of inattention or hyperactivity-impulsivity that do not meet all criteria for ADHD. However, if the unmet criterion is “symptoms are not better accounted for by another mental disorder,” the diagnosis of ADHD is questionable.7 Similar proportions of the three major subtypes have been identified in clinical trials (few reports of the results of clinical trials, however, include these data). For example, in a study of 221 adults with ADHD (mean age 38.7 years) by Spencer and colleagues,17 70% of the subjects were of the combined type, 27% the inattentive type, and 3% the hyperactive-impulsive type. In other studies, the respective proportions have been 63%, 37%, and 0% (N=162; 40.2 years)18; 66%, 31%, and 2% (N=536; 41.2 years)19; 56%, 37%, and 2% (N=149; 37.0 years)20; and 55%, 34%, and 2% (and 9% of the residual type; N=105; 20.7 years).21 Lahey and colleagues22 reported that most hyperactive-impulsive children developed the combined type during their early school years, while inattentive children tended to remain inattentive. McGough and Barkley8 noted that in many cases patients who might have been diagnosed with the combined type as youths will appear to have the inattentive type in adulthood.

Symptoms of ADHD in Adults

The symptoms of ADHD seen in pediatric patients shift as patients enter adulthood.7,23,24 In adulthood, as roles and responsibilities change, symptom manifestations may also change, particularly hyperactivity-impulsivity symptoms.14,23

Symptoms of inattention in children may include difficulty sustaining attention in tasks or play activities, not listening when spoken to directly, not following through on instructions, or losing things necessary for tasks or activities.7 In adults with ADHD, these symptoms may be expressed as difficulty finishing tasks, poor time management, difficulty sustaining attention when reading or doing paperwork, distractibility and forgetfulness, and poor concentration.14,23 Among the 149 clinically referred adults with ADHD in the study by Millstein and colleagues,20 the most commonly reported symptoms were difficulty following through on tasks, difficulty sustaining attention, and shifting activities frequently, endorsed by an average of 92% of the patients. In contrast, 58% endorsed an ADHD subtype that includes symptoms of hyperactivity-impulsivity.

Symptoms of hyperactivity in children may include fidgeting, running, or climbing in inappropriate situations; difficulty quietly playing or engaging in leisure activities; or talking excessively. Impulsive childhood symptoms include blurting out answers or difficulty awaiting turn (in conversation, in games).7 In adults, symptoms of hyperactivity can present as subjective feelings of restlessness, choosing active jobs that require a lot of energy, and working at multiple jobs.23 Symptoms of impulsivity in adults may present as finishing or interrupting others’ sentences during conversation, impulsive or multiple job changes, and interrupting others when they are busy.23,25 Additionally, a low frustration tolerance can lead to irritability, quickness to anger, and high relationship turnover.14 Impulsivity can be highly impairing in that impulsive acts cannot be taken back once they have occurred. In contrast, consequences of inattentive symptoms can often be corrected.

Current DSM-IV-TR criteria may not accurately represent adult symptom manifestation even among adults who continue to experience significant impairment. Barkley and colleagues26 have recommended the adoption of nine criteria for the diagnosis of ADHD in adults (Table 3). The authors noted that only three of the items (numbers 1, 8, and 9) are from the DSM-IV-TR and that none concern hyperactivity. Data from this study, as well as from a study conducted by Faraone and colleagues,10 have led some to question whether the age-of-onset criteria should be pushed further back to 12 years of age.

 

 

 

Prevalence and Potential Consequences of ADHD in Adults

According to data from the National Comorbidity Survey Replication (NCSR; N=3,199 respondents 18–44 years of age), the prevalence of clinician-assessed ADHD in the general adult population of the US is 4.4%.27 The estimate for the US from the World Health Organization (WHO) World Mental Health Survey Initiative (N=3,197 US respondents 18–44 years of age) was a little higher at 5.2%.28 The overall prevalence of ADHD in adults in the 10 countries from the WHO survey (N=11,422) was 3.4% (range=1.2%–7.3%).28 When examined by employment status in the US, the rate of ADHD in employed or self-employed respondents (4.5%) was significantly lower than the rate in unemployed respondents (7.2%; P=.021).29 Based on these statistics extrapolated to estimates of the full US population of 222,940,420 adults ≥18 years of age (July 2005),30 ADHD may affect an estimated 10 million adults in the US (4.4% prevalence x 223 million=9.8 million). The proportion of adults in the NCSR who received treatment for ADHD was only 10.1% of men and 12.1% of women, indicating that ADHD remains undiagnosed and untreated in millions of adults in the US.27

The growing acknowledgment of ADHD in adults as a valid diagnosis indicates that the number of adults seeking professional attention for the disorder will increase in the years to come.23 According to an analysis of pharmacy claims data for >2.5 million participants in prescription benefit plans, approximately 1% of the participants ≥20 years of age were treated for ADHD with medication.31 When the estimated prevalence rate of 4.4%27 is applied to this population, the result is a pharmacologic treatment rate of 22.7%.

The potential consequences of ADHD in adults have been described in several studies.21,23,29,32,33 Awareness of some of the educational, social, and occupational problems experienced by many adults with ADHD may prompt the identification of these people. In the studies reviewed below, most of the respondents with ADHD were not receiving treatment for ADHD.

To evaluate functional impairments associated with ADHD, Biederman and colleagues33 conducted a telephone-interview survey of a community sample of 500 adults (mean age=32 years) who reported having been diagnosed with ADHD, and 501 sex- and age-matched adults who did not have ADHD (controls; mean age=33 years). The adults with ADHD were significantly less likely to have graduated from high school than those without ADHD (7% vs. 17%; P≤.001) and less likely to have attained a college degree (19% vs. 26%; P<.01). Fewer were currently employed (52% vs. 72%; P≤.001) or had full-time jobs (34% vs. 57%; P≤.001), and those with ADHD were significantly more likely to be looking for work (14% vs. 5%; P≤.001). They were also twice as likely to have been arrested (37% vs. 18%; P≤.001), 1.5 times more likely to have received more than one speeding ticket in a 12-month period (25% vs. 17%; P≤.01), 1.8 times more likely to report an addiction to tobacco (64% vs. 36%; P≤.001), and 1.6 times more likely to report recreational drug use (52% vs. 33%; P≤.001).33

Barkley and colleagues32 assessed outcomes in 158 respondents rigorously diagnosed as hyperactive in childhood and 81 community controls who were followed up for ≥13 years. From each group, 94% participated in the follow-up study: 149 of the original 158 members of the hyperactive group and 76 of the original 81 members of the control group. The respondents were primarily male (91%) and Caucasian (94%). Their mean age at follow-up was 21 years (range 19–25 years) and 8.1% of the hyperactive group and 1.3% of the control group were taking psychiatric medications, primarily stimulants and some antidepressants. Significantly more of the hyperactive group had been suspended during high school (60% vs. 18%, P<.001) or had received special education (44% vs. 10%, P<.001), and significantly fewer had graduated from high school (68% vs. 100%, P<.001) or enrolled in college (21% vs. 78%, P<.001). According to the parents’ ratings on the Young Adult Behavior Checklist, the number of social problems experienced was 2.9±2.6 in the hyperactive group and 0.4±0.8 in the controls (P<.001). The hyperactive group reported significantly more sex partners than the controls (13.6±17.1 vs. 5.4±5.1, P<.001) and 17% vs. 4% had contracted a sexually transmitted disease (P=.006).32

In a study of 89 “hyperactive boys almost grown-up” by Mannuzza and colleagues,34 at 16–23 years of age 26% had been arrested more than once (vs. 8% of non-hyperactive controls) and 20% had been convicted of an offense more than once (vs. 2% of controls). Additionally, in a review of the literature on ADHD and correctional health care, Eme35 reported a 25% prevalence of ADHD among inmates.

A survey of work performance in adults with ADHD was completed recently in 10 countries by the WHO World Mental Health Survey Initiative.29 Days out of role were assessed by asking the respondents the question, “Beginning yesterday and going back 30 days, how many days out of the past 30 were you totally unable to work or carry out your normal activities?” Compared with employed respondents without ADHD, the mean excess days of lost role performance (number of days per year either absent or with reduced quantity or quality of work) was 22.1 days in the total ADHD group and 28.3 days in the ADHD respondents in the US (both P<.05 vs. respondents without ADHD). Among the 2,387 employed respondents with ADHD in the US sample, only 12.6% had received any treatment for ADHD.29

Complexities of Diagnosis

Diagnosis of ADHD in adults may be challenging because, like all psychiatric disorders, no objective medical or neuropsychological test can be used to make or confirm the diagnosis, and there is no established consensus on the specific symptom cluster for ADHD in adults.15 Making the diagnosis in an adult requires using different resources than are often available when making the diagnosis in a child. With children, parents or teachers see the child intensely for significant time periods, but in adults, there is often no one person who sees the patient throughout the day (a reporter from work may miss symptoms at home and a significant other may under-report symptoms at work). Thus, the careful review of history by the clinician that integrates self-reports and other information recommended for the valid assessment of symptoms and impairments may be more difficult to obtain in the adult patient.14

Adult patients with ADHD often have similar educational, occupational, and social impairments. Many adults with ADHD may have failed to live up to their potential and present with problems related to diminished educational achievement or vocational training. Others may present with work-related problems that can be task specific or may involve interpersonal interactions. Other common presentations may involve marital or relationship difficulties.

Adults with ADHD experiencing symptoms for years frequently develop compensatory strategies that help minimize the observable manifestation of impairments, thereby hiding symptoms from others.14 These compensatory strategies can complicate the diagnosis of ADHD by making impairments less evident to clinicians. Therefore, clinicians need to evaluate the degree of compensation when assessing symptom severity. In addition, impairment related to a few specific symptoms may have serious consequences even if problems only occur in a few situations. For example, interruptions may be rare, but if they occur at critical or inappropriate times, such as with a superior or in a courtroom, the consequences can be serious. A person with ADHD may have learned to check carefully at home to ensure that he or she has not forgotten something, and then may be chronically late for work resulting in a poor job review. Therefore, observable impairments result from intelligence level, compensatory skills, and environmental demands. Establishing effective coping mechanisms is an important goal of cognitive-behavioral therapy in patients with ADHD.36,37

Assessment of ADHD symptoms can be complicated by their nonspecific nature. For example, the inattentive symptoms seen with ADHD may resemble concentration impairments that occur in major depressive disorder (MDD), dysthymia, posttraumatic stress disorder, and generalized anxiety disorder (GAD). ADHD inattention symptoms can also resemble the distractibility of a manic or hypomanic episode. Furthermore, some hyperactivity symptoms of ADHD, such as motoric restlessness and excessive talking, can be difficult to distinguish from the symptoms of restlessness in GAD or psychomotor agitation associated with mania, hypomania, or MDD. Similarly, the impulsive symptoms seen with ADHD may resemble the impulsivity characteristic of manic and hypomanic episodes38 or borderline personality disorder.7 Some of these complexities can be addressed during the clinical interview by asking questions using adult-specific language and context. Diagnostic accuracy rests on the longitudinal course of cross-sectional cognitive and behavioral symptoms tracked back to the age of onset.

Comorbid ADHD is common in patients with other psychiatric disorders and comorbid psychiatric disorders are evident in a high proportion of adults with ADHD. High rates of mood, anxiety, and substance use disorders have been reported in community studies of adults with ADHD and in national and international surveys. Mood disorders are often present in adults with ADHD with reported rates of comorbidity between 53% and 59%,39,40 and MDD has been shown to be present in 10% to 55% of adults with ADHD.40-46 Bipolar disorder/mania is another frequently comorbid condition, reported in 9% to 14% of adults with ADHD,40,42,43 and dysthymia has been reported in 5.7% to 35% of adults with ADHD.40,44-46 Antisocial personality disorder has also been frequently reported in adults with ADHD with rates of comorbidity between 7% and 17%.39,41-43 GAD is another common comorbid diagnosis in adults with ADHD, with reported prevalence rates between 3% and 53%.39,41,44-46 Substance use disorders also frequently accompany ADHD in adults, with reported comorbidity rates of between 7% and 57%.39-46

Similar patterns of a high prevalence of these disorders in adults with ADHD are seen in data from the NCSR27 and from the 10-nation WHO survey.28 In both surveys, ADHD was assessed according to DSM-IV criteria, and other DSM-IV disorders were assessed using the WHO Diagnostic Interview. In the NCSR, 38.3% of adults with ADHD had a comorbid mood disorder, 18.6% had MDD, 19.4% had a bipolar disorder, 12.8% had dysthymia, 47.1% had an anxiety disorder, and 15.2% had a substance use disorder.27 In the WHO World Mental Health Surveys in 10 countries,28 mood disorders were identified in 24.8% of adults with ADHD, anxiety disorders in 38.1%, and substance use disorders in 11.1%.

Comorbid ADHD is found in a large proportion of adults with other psychiatric disorders. The US NCSR27 identified ADHD in 22.6% of adults with dysthymia, 21.2% of adults with bipolar disorder, 11.9% of adults with GAD, 10.8% of adults with a substance use disorder, and 9.4% of adults with MDD. In the WHO World Mental Health Survey,28 ADHD was identified in 12.5% of adults with a substance use disorder, 11.1% of adults with mood disorders, and 9.9% of adults with anxiety disorders. Furthermore, in a study by Alpert and colleagues,47 childhood-onset ADHD was diagnosed in >16% of 116 adults enrolled in a treatment program who had a current episode of MDD. Both the MDD and ADHD were diagnosed according to DSM-III-R criteria.

Currently Available Rating Scales

Several major self- and clinician-rated scales are currently available to assess whether an adult meets the DSM-IV-TR criteria necessary for a diagnosis of ADHD. Descriptions of some of the available scales are provided in Table 4.14,25,48-67 Enumeration of current symptoms, impairments, and childhood onset of symptoms remain the affirming factors in the diagnosis of ADHD.14 Rating scales provide the basis for the diagnostic interview or supplement it by providing structure and, in some cases, extensive prompts can be used to probe patients further. While the use of rating scales can provide valuable information, it is critical to filter patient reports through the prism of skepticism since patients may assess symptoms in settings in which they are less impaired (ie, tasks that they find easy or interesting) and not the more challenging ones. As a case in point, baseline investigator ratings were stronger predictors of treatment outcome than baseline patient self-report scores on the Conners Adult ADHD Rating Scale.68 Rating scales can also be used to measure patient response to treatment and changes in quality of life.

 

 

 

 

 

Neuropsychological Tests

Neuropsychological testing is generally reserved for cases of diagnostic uncertainty or for educational reasons. Seidman69 reported that >70 tests are available to assess neuropsychological functioning in adults with ADHD. Many, however, were used in only one or two studies, and their sensitivity cannot be determined. Instead, Seidman highlighted five tests that most consistently differentiated people with ADHD from controls and were used in ≥7 studies. These were versions of the Continuous Performance Test (CPT), including the Conners CPT, Gordon Diagnostic System, and a number of “home-grown” visual CPTs; the Stroop Color Word Task; the Trail Making test; the Verbal Fluency test; and the Wechsler Adult Intelligence Scale.

In a study of 213 adults who met DSM-IV criteria for ADHD and 145 matched comparison subjects, Biederman and colleagues70 found that 31% of subjects with ADHD had executive function deficits. This study examined sustained attention/vigilance, planning and organization, response inhibition, set shifting and categorization, selective attention and visual scanning, verbal and visual learning, and memory. The results suggest that many people with ADHD do not have these deficits and that reliance on neuropsychological testing to make a diagnosis will miss most of those affected. Additionally, the results of several studies suggest that neuropsychological testing cannot definitively distinguish between those with ADHD and those without.71-74 This further highlights the importance of clinical assessment in making a correct diagnosis of ADHD in adults. Cognitive assessments, however, can improve the validity of an ADHD assessment and can be used to evaluate treatment outcomes.75

Conclusion

The persistence of ADHD symptoms into adolescence and adulthood in many patients strongly supports the concept that ADHD is a lifelong disorder for many patients. Although the symptoms of ADHD seen in pediatric patients may shift as patients enter adulthood, the consequences of adult symptoms of ADHD are no less serious. During clinical evaluation, symptom assessment is essential but not sufficient to diagnose this disorder. The chronicity and pervasiveness of ADHD symptoms, as well as impairment due to ADHD symptoms, are critical to the correct diagnosis of ADHD in adults. The DSM-IV-TR criteria for ADHD still provide the basis for diagnosis despite several limitations involving the different manifestations of ADHD symptoms from childhood to adulthood, such as the possible attenuation of hyperactive-impulsive symptoms. Core inattentive symptoms may continue into adulthood and often drive the presentation of ADHD in adults. Additional complexities to making an accurate diagnosis include patient coping strategies, symptom profiles that overlap with other DSM-IV-TR disorders, and frequent comorbidity with other DSM-IV-TR disorders. Diagnosis may be assisted through the use of several recently developed screening and diagnostic instruments for assessment of ADHD in adults, specifically those that employ adult-specific language to circumvent some of the shortcomings associated with the child-centered DSM-IV-TR criteria for ADHD.

Accurately diagnosing ADHD is critically important, as highlighted by the findings of Barkley and colleagues32 and Biederman and colleagues.33 These studies demonstrate that missed diagnosis and the absence of treatment were associated with educational, occupational, and social impairments in adaptive functioning, as well as an increased risk of substance use disorder. Because of the high prevalence rate of ADHD relative to other Axis I psychiatric disorders, clinicians should be aware of the symptoms and adult manifestations of ADHD and include screening in every adult psychiatric evaluation. Rating scales can be helpful in complementing the clinical interview, quantifying target symptoms, and measuring treatment response. PP

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