hyperactivity disorder: a practical guide to diagnosis in primary care.

C L I N I C A L F O C U S : A D H D, P S Y C H I AT R I C D I S O R D E R S , A N D S T R O K E A N D N E U RO L O G Y

Postgraduate Medicine Downloaded from informahealthcare.com by University of Pennsylvania on 04/12/15 For personal use only.

Comorbidities in Adult Attention-Deficit/ Hyperactivity Disorder: A Practical Guide to Diagnosis in Primary Care

DOI: 10.3810/pgm.2014.09.2799

Alice R. Mao, MD 1 Robert L. Findling, MD, MBA 2 Baylor College of Medicine, Houston, TX; 2Johns Hopkins University and the Kennedy Krieger Institute, Baltimore, MD 1

Abstract: Diagnosis and management of attention-deficit/hyperactivity disorder (ADHD) in adults is complex and challenging because of the frequent comorbidity of other psychiatric disorders that have symptoms overlapping with those of ADHD. The presence of comorbidities can create challenges to making an accurate diagnosis and also impact treatment options and outcomes. This review discusses disorders that may be comorbid with ADHD in adults, including anxiety, mood, substance use disorder, antisocial personality disorder, and borderline personality disorder. Suggestions for recognizing these comorbidities and distinguishing them from ADHD and perspectives on their possible impact on ADHD treatment are included. Adjunctive nonpharmacologic modalities may be especially helpful in the case of comorbid mood, anxiety, substance abuse, or personality disorders. Keywords: attention-deficit/hyperactivity disorder; comorbidity; adults; pharmacotherapy

Introduction

Correspondence: Alice R. Mao, MD, Baylor College of Medicine, 550 Westcott Drive, Suite 520, Houston, TX 77007. Tel: 713-864-6694 Fax: 713-864-6698 E-mail: [email protected]

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Attention-deficit/hyperactivity disorder (ADHD) is a common psychiatric disorder, usually first seen in childhood but frequently persisting into adulthood. In a largescale survey among adults in the United States (N = 3199), the estimated prevalence of ADHD was 4.4%.1 Although the key symptoms—inattention, hyperactivity, and impulsivity2—may characterize ADHD in adults, the clinical presentation often differs from the presentation in children. The definition of ADHD has been updated in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5), to more accurately characterize the experience of affected adults.2 At least 6 symptoms from either or both the inattention group of criteria and the hyperactivity and impulsivity criteria are required for a diagnosis of ADHD in children. However, a lower threshold—5 symptoms instead of 6—is sufficient for a diagnosis of ADHD in older adolescents and adults (aged . 17 years).2 Lowering the symptom threshold for adults in the DSM-5 is an important step for improving ADHD diagnosis in adults, as evidenced by a recent study that indicated that lowering the hyperactive-impulsive symptom threshold on the DSM, 4th edition (DSM-IV), from 6 to 4 substantially increased the number of adults identified who exhibited elevated scores on the Conners’ Adult ADHD Rating Scale Self-Report: Long Form.3 The DSM-5 states that ADHD symptoms must be present prior to age 12 years, as opposed to 7 years based on the text revision of the DSM-IV (DSM-IV-TR),4 which may help to identify those adults who were referred to treatment later for a variety

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Comorbidities in Adult ADHD

of reasons. Children and adolescents with ADHD who have higher intellectual functioning may be able to compensate for their inattention symptoms when the schoolwork is less challenging; however, as the academic demands increase they are less able to manage the schoolwork. Consequently, more adults with ADHD who had symptoms emerging between the ages of 6 and 12 can meet the criteria for diagnosis of ADHD. Inattention often is the predominant symptom in adults with ADHD,5–7 most commonly manifested as poor time management, poor concentration, and poor motivation.5 However, problems with attention are present in many psychiatric disorders and, as a result, may not be particularly useful for differential diagnosis.8 In adults, ADHD is characterized by distractibility, making impulsive decisions, problems with driving, and executive deficits that affect perseverance in activities.8 Hyperactivity in adults with ADHD is less overt than typically seen in children. Inner restlessness may present as excessive fidgeting or difficulty staying still for extended periods6 or as a tendency to work excessively.9 Irritability and a short temper may also be characteristics seen in adults with ADHD.6 Impulsivity in adults with ADHD may manifest as impatience, impaired executive skills, and impaired ability to evaluate situations, plan, and complete assigned tasks.6,10 On the basis of the estimated prevalence of ADHD in adults and reported data on annualized rates of office visits resulting in a diagnosis of ADHD, it is believed that as many as 90% of adults with ADHD may go undiagnosed and untreated.5 Nontreatment of ADHD in adults may result in poor long-term outcomes, increased use of medical resources, and higher medical costs.11,12 For these reasons, clinicians should screen for ADHD in adults. A clinical history that reveals longstanding inattention, restlessness, impulsivity, unstable relationship history, mistakes at work that lead to termination, or personal financial management difficulties should raise suspicion of possible ADHD.6,13 Unfortunately, failure to recognize ADHD in adults may be attributable in part to the misperception that the condition remits in adolescence, despite evidence to the contrary.7 The recognition and diagnosis of ADHD in adults can also be complicated by the presence of comorbid psychiatric conditions. As primary care physicians are likely to have to diagnose and treat individuals with ADHD who also have comorbid psychiatric disorders, they should understand the presentation of ADHD in adults and how to differentiate its symptoms from those of comorbid psychiatric disorders. A detailed and accurate clinical history is of paramount importance in sorting out the symptoms of a psychiatric

disorder. Determining whether the onset of symptoms suggestive of comorbid psychiatric disorders preceded or followed the onset of ADHD, whether these symptoms are episodic and linked to certain settings or situations, and whether these symptoms are chronic and present in all environments may help establish whether a condition is secondary to (comorbid with) or independent of ADHD. Effective treatment may resolve ADHD symptoms and some symptoms of a condition secondary to ADHD. However, this is not always the case. For example, pharmacotherapy for ADHD symptoms in an individual with a comorbid mood disorder (eg, bipolar disorder) can cause symptomatic worsening of mood symptoms.14 This article provides primary care clinicians with a practical overview of the psychiatric disorders often comorbid with ADHD in adults, with a focus on general guidelines for approaching the differential diagnosis. We also examine how the new DSM-5 criteria for ADHD may have implications for the diagnosis of comorbid disorders. The comorbid disorders highlighted in this review were selected based on the authors’ clinical experience in treating adults with ADHD and based on the need for general practitioners to rule out the most frequent comorbid disorders when developing treatment plans for adults with ADHD.

Adult ADHD Rating Instruments

Coupled with the use of DSM-5 criteria, clinicians have several assessment tools that can be used in adult patients who have suspected symptoms of ADHD. These scales assess several parameters, including symptom severity (ie, Adult ADHD Self-Report Scale,15,16 Conners’ Adult ADHD Rating Scale17), functional impairment (ie, Weiss Functional Impairment Rating Scale18), and quality of life (ie, Adult ADHD QOL [Quality of Life] Scale19). There are many such instruments available; Table 1 summarizes a few select instruments that may be useful for primary care physicians. Screening for ADHD can begin as part of a routine review of systems by a clinician. McIntosh et al20 has recommended 1 potential path that could be used by primary care physicians to start the process of assessing ADHD in adults. The clinical interview includes 3 questions: 1. Have you ever been diagnosed with ADHD? 2. Do you have a family history of ADHD? 3. Did you have any difficulty in school?20 If the answer is yes to $ 1 of these questions, the next step is to assess whether the individual has substantial difficulties with forgetfulness, attention, impulsivity, or restlessness that are interfering with relationships or success at work.20 If a positive answer is given, the clinician should utilize

© Postgraduate Medicine, Volume 126, Issue 5, September 2014, ISSN – 0032-5481, e-ISSN – 1941-9260 43 ResearchSHARE®: www.research-share.com • Permissions: [email protected] • Reprints: [email protected] Warning: No duplication rights exist for this journal. Only JTE Multimedia, LLC holds rights to this publication. Please contact the publisher directly with any queries.

Alice R. Mao and Robert L. Findling

Table 1. Selected Symptom, Functionality, and Quality of Life Assessment Tools for Adults With ADHD Scale

Description

Assessment

Adult ADHD Self-Report Scale (ASRS)15,16

18 questions Self-report

Conners Adult ADHD Rating Scales (CAARS)17

2 formats: self-report ratings and observer ratings

Symptom frequency is often associated with symptom severity Insights gained through this screening may suggest the need for a more in-depth clinical interview Nine empirically derived scales that help assess a broad range of problem behaviors: inattention/memory problems, impulsivity/emotional lability, hyperactivity/restlessness, and problems with self-concept Includes DSM-5 ADHD symptom measures, ADHD Index (12 items that help identify respondents who may benefit from a more detailed clinical assessment), and Inconsistency Index to identify random or careless responding Multiple domains assessed including family, work, school, life skills, self-concept, social life, and risk-taking Specific measure of functional impairment (quality of life) To assess HRQOL during the past 2 weeks Assesses life productivity, psychological health, life outlook, and relationships

3 versions: long, short, and screening versions


Weiss Functional Impairment Rating Scale18 Adult ADHD Quality of Life Scale19

70 questions Self-report 29 items Self-report

Abbreviations: ADHD, attention-deficit/hyperactivity disorder; DSM-5, Diagnostic and Statistical Manual of Mental Disorders, 5th edition; HRQOL, health-related quality of life.

a validated screener, such as the Adult ADHD Self-Report Scale, as a screening aid and a baseline measure of symptom severity.20 Based on the results of this screening, a more in-depth clinical interview may be warranted to confirm or refute the diagnosis.

Increased Prevalence of Psychiatric Comorbidities and Learning Disorders in Adult ADHD

The frequent presence of psychiatric comorbidities in adult ADHD makes accurate diagnosis and appropriate treatment difficult.5,6,21 As more adults may be diagnosed with ADHD using the new DMS-5 criteria, it is possible that individuals with a previously diagnosed psychiatric disorder will also meet the criteria for a comorbid ADHD diagnosis. In the US survey by Kessler et al,1 47.1% of respondents with ADHD had a comorbid anxiety disorder, 38.3% had a comorbid mood disorder, and 15.2% had a comorbid substance abuse disorder; prevalence rates for these types of conditions were much lower in respondents without ADHD (19.5%, 11.1%, and 5.6%, respectively). In a Canadian study, 71.9% of adults with an ADHD diagnosis had an additional DSM-IV-TR axis I disorder (most commonly, anxiety disorders and mood disorders) and 50.9% had a comorbid DSM-IV-TR axis II disorder.22 Learning disabilities and medical comorbidities are also common in adults with ADHD.11 Cognitive symptoms of ADHD (eg, inattention) can possibly mask a learning disability, making the diagnostic distinction difficult.8 For example, when an adult presents with a long history of academic problems, it is important for the clinician to consider undiagnosed ADHD or an undiagnosed learning disability 44

as a possible explanation for poor academic achievement. Formal intellectual testing will need to be done to diagnose a learning disability. Similarly, autism spectrum disorder (ASD) can be comorbid with ADHD, though the prevalence of ASD in adult ADHD is not yet clarified.2,23 Similarly, the presence of mood disorders or substance use disorders can obscure ADHD symptoms.8 These conditions should also be considered as part of the differential diagnosis when evaluating adults presenting with nonspecific symptoms, such as inattention, distractibility, affective instability, and irritability.

Comorbid Psychiatric Disorders Anxiety/Trauma- and Stressor-Related Disorders

In the aforementioned Canadian study of adults with ADHD, prevalence rates of current comorbid anxiety disorders were 6.0%, 11.0%, and 6.6% for specific phobia, social phobia, and panic disorder, respectively, all significantly greater rates than in adults without ADHD (0.9%, 4.5%, and 2.7%).22 In the Kessler US survey, the corresponding prevalence rates for the same conditions among adults with ADHD (vs adults without ADHD) were higher than in the Canadian study but showed a similar pattern: 22.7% versus 9.5%, 29.3% versus 7.8%, and 8.9% versus 3.1%, respectively; the prevalence of any comorbid anxiety disorder was more than twice as high in adults with versus adults without ADHD (47.1% vs 19.5%).1 The differentiation of ADHD from anxiety disorders in adults may present a diagnostic challenge. Individuals who have generalized anxiety disorder (GAD) could resemble those who have ADHD because both conditions may present with impaired concentration in social and occupational areas




of functioning.2 However, adults with ADHD do not typically have the excessive anxiety and worry causing muscle tension, fatigue, and sleep disturbance characteristic of GAD.2,11 In the US survey, the prevalence of comorbid GAD was 8.0% in adults with ADHD versus 2.6% in adults without ADHD.1 A screening instrument available to primary care physicians in assisting in the identification of comorbid GAD is the 7-item generalized anxiety scale.24 Posttraumatic stress disorder (PTSD) may also be comorbid with ADHD, and the symptoms of PTSD may overlap with symptoms of ADHD. In the general US population, the 12-month prevalence of PTSD is significantly greater among adults with ADHD (11.9%) than among adults without ADHD (3.3%).1 In addition, 11.5% to 28% of veterans with PTSD have been reported to meet criteria for a current diagnosis of ADHD.25,26 Symptoms of PTSD (eg, irritability, reckless or selfdestructive behavior, problems in concentration, sleep disturbance, and hypervigilance) may be related to or exacerbated by the inattention or hyperactivity symptoms of ADHD.2,27 Among veterans, the severity of PTSD arousal-related symptoms has been found to be significantly related to the severity of inattention in ADHD.26 In order to differentiate the 2 conditions from each other, it should be recalled that the intrusive reexperiencing of traumatic events, avoidance of reminders of traumatic events, and the negative cognition and mood that characterize PTSD2 are not typically displayed in individuals with ADHD. Similarities and differences in the presentations of ADHD and anxiety and trauma- and stressor-related disorders are summarized in Table 2. There are several validated rating

instruments available to primary care clinicians to assist in the identification of PTSD in individuals with ADHD including the PTSD Checklist.28 The clinical importance of identifying anxiety and trauma- and stressor-related disorders in an adult patient with ADHD is that treatment decisions regarding pharmacotherapy selection will be impacted. Psychostimulants are first-line pharmacotherapy for ADHD,29,30 but there may be concern regarding the potential for psychostimulants to induce or exacerbate anxiety31,32 and sleep disturbances33; in such cases, the prescriber may consider use of a nonstimulant, such as atomoxetine, for the treatment of ADHD to avoid unintentional worsening of symptoms.

Mood Disorders

The comorbid presence of mood disorders in adults with ADHD is well established. In the US survey, the prevalence of any comorbid mood disorder was 38.3% in adults with ADHD versus 11.1% in those without ADHD, and the prevalence of major depressive disorder (MDD) was 18.6% versus 7.8%.1 These prevalence estimates for comorbid MDD in the US study are consistent with those reported in the Canadian study (19.1% vs 7.1%).22 The US survey also reported prevalence rates of 19.4% for comorbid bipolar disorder in adults with ADHD versus 3.1% in those without ADHD.1 Several factors, including age of symptom onset, presenting symptoms, and family history, should be considered when making the diagnostic distinction between MDD and ADHD.34 Although the age of onset for ADHD is typically in childhood, the age of onset of MDD is often in adolescence.34

Table 2. Anxiety/Trauma- and Stressor-Related Disorders

GAD Associated mainly with GAD Overlapping with ADHD PTSD Associated mainly with PTSD

Overlapping with ADHD

DSM-5 Features and Diagnostic Characteristics2

Comparative Characteristics in Uncomplicated Adult ADHD

Psychiatric (eg, uncontrollable and excessive worrying) and somatic (eg, fatigue, muscle tension, and sleep disturbance) anxiety symptoms Difficulty concentrating, distractibility Irritability

Absent11

Recurrent intrusive and distressing memories, dreams, or dissociative reactions (ie, flashbacks) related to traumatic events; marked psychological distress related to traumatic events; physiological reactions to cues that are associated with traumatic events Persistent avoidance of trauma-related thoughts, memories, feelings, or external reminders Negative cognition and mood related to the traumatic event (eg, persistent sense of blame, diminished interest in activities, and inability to remember key aspects of an event) Restlessness/hyperactivity, impulsivity or reckless behavior, or problems with concentration

Absent

Present; related to inattention11 Present; related to frustration11

Absent Absent

Present; related to inattention26,27

Abbreviations: ADHD, attention-deficit/hyperactivity disorder; DSM-5, Diagnostic and Statistical Manual of Mental Disorders, 5th edition; GAD, generalized anxiety disorder; PTSD, posttraumatic stress disorder. © Postgraduate Medicine, Volume 126, Issue 5, September 2014, ISSN – 0032-5481, e-ISSN – 1941-9260 45 ResearchSHARE®: www.research-share.com • Permissions: [email protected] • Reprints: [email protected] Warning: No duplication rights exist for this journal. Only JTE Multimedia, LLC holds rights to this publication. Please contact the publisher directly with any queries.



In contrast to MDD, ADHD is not generally associated with marked sleep disturbances, suicidal tendencies, appetite changes, or diminished energy levels.2 A family history may also be helpful for accurate diagnosis.34 Patients with bipolar disorder should be screened during an euthymic phase for the possibility of comorbid ADHD because some of the manic features of bipolar disorder, such as pressured speech, flight of ideas, and changes in activity levels, could appear similar to the hyperactivity, irritability, and distractibility seen with ADHD. However, a manic episode of bipolar disorder should be considered as the most likely diagnosis, with acute onset of severe symptoms such as psychosis, grossly inappropriate and erratic behavior, grandiosity, irritability, decreased sleep, and increased energy.20 Indeed, adults with bipolar disorder and comorbid ADHD typically have more hypomanic and affective episodes than those with bipolar disorder alone.35 Similarities and differences in the presentations of ADHD and mood disorders are summarized in Table 3. Screening instruments available to primary care clinicians to assist in the identification of comorbid mood disorders in individuals with ADHD include the Patient Health Questionnaire-9 for MDD and the Mood Disorder Questionnaire for bipolar disorder.36,37

In patients with a comorbid mood disorder, it is recommended that the affective disorder be treated with pharmacological intervention(s) before the ADHD. The patient should then be reassessed for residual symptoms of ADHD once the mood state is effectively addressed. If ADHD symptoms remain problematic and cause functional impairment, they should generally be treated with a stimulant unless there is a contraindication to do so. Identifying a comorbid mood disorder in an adult with ADHD is important in view of the concern that psychostimulant drugs for ADHD could exacerbate symptoms associated with mood disorders. For example, sleep disturbances, which are often reported in individuals with MDD,38 are also adverse events that can be associated with psychostimulant medications.33 In bipolar disorder, treatment with stimulant medications can be associated with the acute onset or exacerbation of mania/ hypomania,14 so nonstimulant options for treating ADHD may be warranted.

Substance Use Disorders

Estimates of the prevalence of comorbid substance abuse in adults with ADHD vary widely. The US survey reported a rate of 15% within the last 12 months.1 An earlier study reported

Table 3. Mood Disorders

MDD Associated mainly with MDD




Changes in appetite Insomnia or hypersomnia Suicidal ideation Diminished energy level Persistent sadness, apathy, and anhedonia for $ 2 weeks Episodic symptom severity Irritability Psychomotor agitation/retardation

Normal appetite11 Normal or shortened sleep6,11,65 Absent11 Normal/hyperactive energy level6 Normal interest in daily activities11 Symptoms are noncyclical and chronic6 Present; episodic outbursts6 Agitation present; results from chronic hyperactivity6,11 Present; related to chronic inattention and distractibility6,11

Impaired cognition and concentration Bipolar disorder Associated mainly with bipolar disorder

Discrete and cyclical onset of manic and depressive episodes


Excessive goal-directed activity and self-gratification Insomnia Extreme elevated, expansive, or irritable mood for $ 1 week Extremes of grandiosity and self-esteem; racing thoughts Excessive talkativeness Distractibility, agitation Extremes of depression (see above)

Shared depressive-like symptoms are noncyclical and chronic6 Absent Normal or shortened sleep6,11,65 Elevated energy is chronic and restless in nature6,11 Excitement and impulsivity6 Self-esteem impaired6,66 Present, but responsive to social cues6,11 Present6,11 See above

Abbreviations: ADHD, attention-deficit/hyperactivity disorder; DSM-5, Diagnostic and Statistical Manual of Mental Disorders, 5th edition; MDD, major depressive disorder.

46




a lifetime prevalence of 40%.39 In another study of patients receiving long-term methadone maintenance treatment for opioid dependence, comorbid ADHD was reported in 25% of patients and was associated with more severe addiction and greater psychopathology.40 Although the problem of substance abuse in adults with ADHD has been highlighted in multiple review articles,11,41 ADHD often is undiagnosed in those with substance abuse disorders.40–42 In a study of adults in a substance abuse treatment program, only 3% of participants had ADHD based on clinical records, but 44% were diagnosed with ADHD following psychological assessment.43 One contributing factor to this lack of recognition may be failure to perform proactive screening for ADHD symptoms that are independent of substance abuse or of other comorbid psychiatric disorders (eg, depression, anxiety).42 The dual diagnosis of ADHD and substance abuse can be challenging in terms of recognition and management. Substance abuse can exacerbate or distort the manifestations of ADHD and interfere with ADHD treatment effects and treatment compliance. For example, impulsivity is a characteristic finding in ADHD (albeit less so in adults than in children), and impulse control is impaired by substance abuse. Consequently, impulsivity may be especially severe in individuals with comorbid ADHD and substance abuse, possibly leading to problems with the law.40,42,44 Therefore, just as individuals with ADHD should be assessed for possible comorbid substance abuse, individuals identified as having substance abuse problems should be assessed for behaviors suggestive of ADHD. The diagnosis of ADHD should be deferred until substance abuse has stabilized, even in individuals with a childhood history of ADHD.20 Nonetheless, some stimulant medications used for ADHD are valued as drugs of abuse and individuals with substance abuse disorders may feign ADHD symptoms in order to obtain a stimulant medication.45 In the patient with substance abuse disorder, any prescribed substance with abuse potential may be abused. Similarities and differences in the presentations of ADHD and substance use disorders are summarized in Table 4. There are several screening instruments available to primary care clinicians to

assist in the identification of comorbid substance use disorders in individuals with ADHD, including the CRAFFT (an acronym of the key components in the questions: car, relax, alone, forget, friends, trouble) and the CAGE (an acronym of the key components in the first four questions: cut down on drinking, annoyed at criticisms about drinking, guilty about drinking, and using alcohol as an eye opener).46,47

Learning Disorders

Although learning disorders appear to be independent of ADHD, 20% to 60% of children with ADHD have comorbid learning disorders.48 Therefore, it is very important to ask adults presenting with ADHD symptoms whether they have been previously diagnosed with a learning disorder because a learning disability may impact performance and outcome of treatment. Neuroimaging studies have suggested similar neurodevelopmental differences in the caudate, cerebellum, corpus callosum, and neurobiological dysfunction in children with ADHD and learning disorders, both comorbid and alone.49 For example, implicit sequence learning, a cognitive process mediated by frontal-striatal-cerebellar circuitry appears to be atypical in children with ADHD.50 The presence of comorbid learning disorders can be confirmed with psychological testing and a review of the patient’s academic history.

Autism Spectrum Disorder

Importantly, the diagnostic criteria for ADHD in the DSM-5 now allow for the concurrent diagnosis of ASD and ADHD.2,23 Therefore, it is important for physicians to be able to identify the distinguishing symptoms of each disorder. This is clinically important because a poor outcome with pharmacotherapy for ADHD might occur because of a failure to recognize and address the presence of comorbid ASD. In adults with ADHD, there are few data on comorbid ASD. However, 1 study of male prison inmates found that 23% (7/30) of adults with ADHD also met DSM-IV-TR criteria for ASD51; however, larger studies are warranted to confirm this finding. Screening instruments available to primary care

Table 4. Substance Use Disorders

Associated mainly with SUD




Repeated, difficult-to-control substance self-administration Substance tolerance Substance withdrawal Impaired social, occupational, or recreational functioning

Absent Absent Absent Impaired functioning related to inattention, hyperactivity, or impulsivity

Abbreviations: ADHD, attention-deficit/hyperactivity disorder; DSM-5, Diagnostic and Statistical Manual of Mental Disorders, 5th edition; SUD, substance use disorders. © Postgraduate Medicine, Volume 126, Issue 5, September 2014, ISSN – 0032-5481, e-ISSN – 1941-9260 47 ResearchSHARE®: www.research-share.com • Permissions: [email protected] • Reprints: [email protected] Warning: No duplication rights exist for this journal. Only JTE Multimedia, LLC holds rights to this publication. Please contact the publisher directly with any queries.


clinicians to assist in the identification of comorbid ASD in adults include the Autism-Diagnostic Interview–Revised52 or the self-administered Autism-Spectrum Quotient,53 which can be used in adults with normal intelligence.


Antisocial Personality Disorder and Intermittent Explosive Disorder

When diagnosing a comorbid behavioral disorder in an adult patient with ADHD, it is important to consider that antisocial behavior typically is hostile and excessively aggressive, whereas disruptive behavior in uncomplicated ADHD is defiant or oppositional but not typically aggressive.2 Similarities and differences in the presentations of ADHD and antisocial personality disorder (ASPD) and intermittent explosive disorder are summarized in Table 5. At this time, there are no validated screeners that could easily be used by primary care physicians to assist in the identification of comorbid ASPD or intermittent explosive disorder in individuals who may also have ADHD. As such, it is necessary for primary care physicians to assess individuals for the presence or absence of specific symptoms of each of these conditions based on the DSM-5 to clarify the diagnosis. Clinicians should be aware of the possibility that stimulant medications could be misused or diverted if prescribed for the treatment of ADHD symptoms particularly in individuals with ASPD. It has been reported that ADHD is associated with a higher lifetime prevalence of intermittent explosive disorder54 and antisocial personality disorder, and that comorbid ADHD with ASPD is observed 4-fold more frequently in men compared with women.22 There was a higher prevalence of ASPD in males versus females with ADHD (17% vs 7%) compared

with those without ADHD (4% and 2%).55 The reverse pattern of comorbidity may be even more striking; among male military recruits identified as having ASPD, 65% also met the diagnostic criteria for comorbid ADHD.56 In terms of clinical differentiation between ADHD and ASPD, self-injury and criminal activity are more prominent in ASPD alone than in adults with comorbid ADHD and ASPD.56

Borderline Personality Disorder

The comorbidity of personality disorders in adults with ADHD has not been extensively explored, but some data on borderline personality disorder are available. Evidence of comorbid borderline personality disorder has been reported in 24.1% of adults with combined-type ADHD.22 Among adults, inhibitory control is more closely linked to ADHD than to borderline personality disorder.57 Furthermore, comorbid mood and anxiety disorders (and their associated symptoms) are more closely linked to borderline personality disorder alone than to comorbid ADHD and borderline personality disorder.58 Impulsivity is a key component of borderline personality disorder and ADHD; however, a recent study reported that stress increased self-reported impulsivity in individuals with borderline personality disorder alone or comorbid with ADHD, but not in individuals with ADHD alone.59 Similarities and differences in the presentations of ADHD and personality disorders are summarized in Table 6. Screening instruments available to primary care clinicians to help identify borderline personality disorder in those who may have ADHD include the McLean Screening Instrument for Borderline Personality Disorder and the Zanarini Rating Scale for Borderline Personality Disorder.60,61 Failure

Table 5. Antisocial Personality Disorder and Intermittent Explosive Disorder DSM-5 Features and Diagnostic Characteristics2 Associated mainly with ASPD

Persistent, intentional unlawful behavior Deceitfulness, lying, manipulation Lacks remorse and empathy Associated mainly with Intermittent Discrete episodes of acting upon aggressive impulses resulting Explosive Disorder in assaults or property destruction Aggressiveness grossly out of proportion to precipitating stressors Overlapping with ADHD Increased incidence of self-injury Increased likelihood of criminal activity Argumentative, defiant, oppositional, disruptive Irritability and aggressiveness Reckless disregard for safety of self or others

Comparative Characteristics in Uncomplicated Adult ADHD Absent Absent Absent Absent Absent Limited relative to ASPD alone56 Limited relative to ASPD alone56 Mild to moderate, but not purposely hostile or negativistic67 Present; related to frustration11 Impulsivity and lack of forethought unintentionally compromises safety

Abbreviations: ADHD, attention-deficit/hyperactivity disorder; ASPD, antisocial personality disorder; DSM-5, Diagnostic and Statistical Manual of Mental Disorders, 5th edition.

48



Table 6. Borderline Personality Disorder

Associated mainly with BPD Overlapping with ADHD



Less impaired inhibition relative to ADHD57 High prevalence of mood and anxiety disorders Impulsivity

Impaired inhibition Lower prevalence relative to BPD Present


Abbreviations: ADHD, attention-deficit/hyperactivity disorder; BPD, borderline personality disorder; DSM-5, Diagnostic and Statistical Manual of Mental Disorders, 5th edition.

to recognize a comorbid personality disorder in an adult with ADHD may lead to the wrong assumption of treatment failure if pharmacotherapy for ADHD does not bring about adequate clinical and functional improvement. In addition, individuals with ADHD and comorbid borderline personality disorder may need additional interventions, such as dialectical behavioral therapy, to address serious symptoms such as self-injury and distorted perception.62

Conclusion

Adult ADHD is often underdiagnosed and undertreated, with as many as 90% of cases of adult ADHD undiagnosed.5 The prevalence of comorbid psychiatric conditions among adults with ADHD varied across different US and Canadian surveys. There is limited information in the literature to guide the clinician in assessing patients with comorbid conditions for ADHD. The frequent presence of comorbid psychiatric disorders in adults with ADHD adds to the complexity of establishing an accurate and complete diagnosis. However, clinicians treating adults for ADHD need to be aware of how to identify the presence of a comorbid condition because comorbid disorders can affect the presentation and course of ADHD. A careful clinical history remains the key element in recognizing ADHD, sorting out symptoms of ADHD and possible comorbidities, and planning treatment. In addition, guidelines set forth by the Canadian ADHD Resource Alliance can aid in this process.63 Treatment guidelines for specific ADHD comorbidities are beyond the scope of this review; however, a frequent strategy is to focus treatment recommendations first on the most disabling disorder (usually depression, anxiety, or substance abuse) and then on the next most disabling condition.5,11 Furthermore, it has been noted that in addition to diagnosing based on symptoms, it is critically important to assess the context of how symptoms of the disorder have affected the patient over their life span.6 In general, stimulants should be used cautiously in individuals with a history of substance abuse, diversion, or legal problems, although a recent review of the literature concluded that adults with a substance abuse disorder do

not generally abuse their stimulant medication.64 Pharmacotherapy for ADHD generally will not exacerbate psychiatric comorbidities, yet clinicians may have concerns about the use of stimulants in adults with ADHD and a comorbid bipolar disorder, anxiety disorders, behavioral disorder, antisocial personality disorder, or substance use disorder and may prefer to prescribe nonstimulant pharmacotherapy to these patients. Treatment of adults with ADHD involves development of a comprehensive treatment plan that may include pharmacological, psychological, and social interventions. Providing education regarding the course of ADHD and ways to manage organizational challenges can be a valuable addition to pharmacotherapy. In addition, supportive psychotherapy or cognitive behavioral therapy may be a valuable adjunctive treatment when the individual is coping with anxiety or diminished self-esteem related to performance failures. Improved awareness of the psychiatric comorbidities that are most often seen in adults with ADHD and familiarity with how symptoms can overlap is essential for establishing an accurate diagnosis and for making appropriate treatment decisions to address patients’ needs and to achieve optimal outcomes.

Acknowledgments

Shire Development LLC (Wayne, PA) provided funding to Complete Healthcare Communications, Inc. (CHC; Chadds Ford, PA) for support in writing and editing this manuscript. Under the direction of the authors, writing assistance was provided by Diane DeHaven-Hudkins, PhD, Robert Gatley, MD, and Craig Slawecki, PhD, employees of CHC. Editorial assistance in the form of proofreading, copyediting, and fact checking was also provided by CHC.

Conflict of Interest Statement

Alice R. Mao, MD, has served on the speakers’ bureau or made presentations to AstraZeneca, Otsuka, Sunovion, and Takeda. Robert L. Findling, MD, MBA, receives or has received research support, acted as a consultant, and/or served on a speakers’ bureau for Alexza Pharmaceuticals, American




Academy of Child and Adolescent Psychiatry, American Physician Institute, American Psychiatric Press, AstraZeneca, Bracket, Bristol-Myers Squibb, Clinsys, CogCubed, Cognition Group, Coronado Biosciences, Dana Foundation, Forest, GlaxoSmithKline, Guilford Press, Johns Hopkins University Press, Johnson & Johnson, KemPharm, Lilly, Lundbeck, Merck, NIH, Novartis, Noven, Otsuka, Oxford University Press, Pfizer, Physicians Postgraduate Press, Rhodes Pharmaceuticals, Roche, Sage, Seaside Pharmaceuticals, Shire, Stanley Medical Research Institute, Sunovion, Supernus Pharmaceuticals, Transcept Pharmaceuticals, Validus, and WebMD.

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