Distinguishing ADHD from juvenile bipolar disorder: A guide for primary care PAs

source:jaapa.com

                                                                                                 

For the past two decades, there has been an ongoing debate regarding the methodology employed to differentially diagnose attention-deficit/hyperactivity disorder (ADHD) and juvenile-onset bipolar disorder (JBPD).¹ ADHD and bipolar disorder are listed as separate diagnoses in theDiagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR); however, the diagnostic criteria overlap, making the differential diagnosis problematic.² Although the accuracy of diagnosis among these disorders has been investigated for years, it has become increasingly relevant as growing numbers of children with severe emotional and behavioral difficulties are identified.³

Attention-deficit/hyperactivity disorder

ADHD is considered the most researched and commonly diagnosed psychiatric disorder of childhood.^4,5 It is characterized by a triad of symptoms (hyperactivity, inattention, and/or impulsivity) that cause impairment in the child's social, educational, relational, occupational, and self-sufficiency roles.⁶ Estimates suggest that ADHD occurs in 5% to 9% of school-age children and is three times more common in boys.⁷ Theories suggest that boys are more likely to receive a diagnosis of the hyperactive subtype since they are more likely to exhibit aggressive, externalizing types of behaviors. Girls are more likely to receive a diagnosis of the inattentive subtype because they are less likely to exhibit the more attention-grabbing symptoms, appearing instead to have more problems with inattention.⁸

For a diagnosis of ADHD, the child must exhibit hyperactive, inattentive, and/or impulsive symptoms before the age of 7 years.² There is lack of empiric support for this established age criterion, however, and it has been criticized as overly restrictive.⁹ Nevertheless, ADHD remains a common childhood diagnosis given to children with uncomplicated forms of the disorder as well as to others with severe disability and comorbidity (eg, depression, conduct disorder, and oppositional defiant disorder).¹⁰

Juvenile-onset bipolar disorder

Historically, JBPD has been less common than ADHD, with an estimated prevalence of 1% to 2%.¹¹ More recently, recognition of bipolar symptoms in children has been growing.^5,12 The increased diagnosis of JBPD stems primarily from an amended concept of bipolar disorder.¹³ Early investigators hypothesized that the disorder would manifest as it does in adults, with distinct episodes of mania and depression, and would be easily differentiated from ADHD.¹⁴ It has become apparent, however, that JBPD's initial manifestations and clinical course distinguish it from adult-onset bipolar disorder (ABPD) and that its signs and symptoms are more similar to those of ADHD.⁷

Unlike ABPD, JBPD is often characterized by a chronic, rapid-cycling, irritable course with symptoms of mania and depression occurring simultaneously.⁵ The classic symptoms of mania often found in ABPD may be absent or difficult to detect in JBPD. Manifestations of JBPD that make it difficult to distinguish from ADHD (and particularly ADHD with comorbid oppositional defiant disorder) include aggressive behaviors, severe affective outbursts or explosive anger, extreme temper tantrums, and increased impulsivity, hyperactivity, and inattention.^11,13

Comorbidity

JBPD is often diagnosed along with other disorders. Up to 24% of affected children present with more than three comorbid conditions.¹

Researchers suggest that 57% to 100% of children with JBPD have comorbid ADHD, while only 11% to 22% of children with ADHD also have JBPD.⁷ Other research suggests that the younger the child when bipolar disorder is diagnosed, the more likely ADHD is to be present also.¹⁵ In a study of adolescent patients with bipolar disorder, 88% with the childhood-onset form and 59% with the adolescent-onset form had comorbid ADHD.¹⁵ Some clinicians and researchers have questioned these comorbidity figures, suggesting that they can be explained by overlapping symptoms, confusion of normal developmental behaviors, and/or shared genetic vulnerabilities.¹⁶Others argue that manic symptoms are not being adequately differentiated from hyperactive symptoms.¹⁷ Some have suggested that children with comorbid JBPD and ADHD have a familial subtype of bipolar disorder.¹⁸Limited diagnostic criteria make overlapping symptoms even more difficult to interpret (see Table 1). In fact, the DSM-IV-TR does not provide distinct diagnostic criteria for JBPD.^4,5 Investigators have attempted to establish consensual definitions and working guidelines for JBPD and ADHD.¹⁹

Presentation

Patients with JBPD and ADHD present with irritability, hyperactivity, accelerated speech, and distractibility. ²⁰ JBPD produces chronic rapid cycling rather than the episodic cycling found in ABPD, so symptoms may appear continuous (ultradian); this makes distinguishing JBPD from ADHD more difficult.¹ Symptoms that the DSM-IV-TR associates with prepubertal mania are not seen in ADHD, however, and may aid in diagnosis. Researchers and clinicians have suggested that these important signs of JBPD (elation, grandiosity, flight of ideas/racing thoughts, decreased need for sleep, and hypersexuality) should receive more attention.²¹There are other distinct manifestations of JBPD, such as extreme and frequent mood lability, extended tantrums, extreme aggression, suicidality (suicidal thinking and behavior), grandiose or self-accusatory delusions, and hallucinations.¹ Additionally, researchers have found that children with JBPD—unlike those with ADHD— have significant elevations on the Child Behavior Checklist (CBCL), a measure of child behavior problems. These elevations indicate more delinquency, aggression, anxiety, depression, and thought problems.²²

By resolving the diagnostic dilemma and providing prophylactic pharmacotherapy, practitioners can reduce the psychiatric and psychosocial morbidity associated with JBPD.²² Medications commonly used to treat ADHD, such as CNS stimulants, atomoxetine, and antidepressants, may be ineffective for children with JBPD and may even exacerbate bipolar symptoms.¹ Also, the use of antidepressants and stimulants in children may trigger mania and result in an earlier onset of bipolar disorder. ¹² The FDA's health advisory suggesting that children and adolescents taking antidepressants may be at increased risk for suicidality highlights the importance of an accurate differential diagnosis.

In light of the significant changes in the health care system and increased demands to improve productivity while containing costs, PAs have become critical members of the pediatric team.²³ As a result, it is imperative that PAs have an accurate understanding of ADHD and JBPD and that they understand the nuances of the differential diagnosis in this population.

Diagnosis

Since the process of diagnosing ADHD and/or JBPD is multifaceted, primary care providers, pediatric psychologists, and psychiatrists often compose the diagnostic team. Many biological and psychological conditions can manifest similarly to ADHD or JBPD. A thorough evaluation should include a complete history and physical examination, laboratory tests, clinical interviews with the child and parent, behavioral rating scales, and other testing as deemed appropriate. The findings from these assessments are then compared to the diagnostic criteria listed in the DSM-IV-TR.^24,25