By Daniel P. Dickstein, M.D.
After much anticipation, the proposed draft of the Diagnostic and Statistical Manual Fifth Edition (DSM-5) has been revealed (www.dsm5.org). Among the proposed changes to the DSM is the acknowledgment of one of child psychiatry's great "elephant in the room": irritability as a diagnostic symptom. In the current version of the DSM (DSM-IV), irritability is everywhere and nowhere simultaneously. Specifically, irritability is the following:
October 2010 Vol. 26, No. 10
This article was published in the Brown University Child and Adolescent Behavior Letter in cooperation with Bradley Hospital.
a) An explicit diagnostic criterion for a manic episode, generalized anxiety disorder, and posttraumatic stress disorder (PTSD) for children or adults.
b) A child-specific modification of the major depressive episode criteria (adults must have depressed mood; children can have depressed or irritable mood).
c) An associated feature of several disorders, including attention-deficit/ hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and autistic spectrum disorders.
Yet, there is no consensus about how irritability is defined in any of these disorders. Nor is there clarity about how to differentiate irritability associated with one disorder from that in another - i.e., distinguishing irritability due to mania from that due to ADHD. Furthermore, there is ambiguity in the duration of a manic episode, whereas DSM-IV clearly specifies that the depressed (or for children, irritable) mood of a major depressive episode must last "most of the day, nearly every day."
Thus, clinicians and researchers alike must "know [irritability] when they see it" (to paraphrase Supreme Court Justice Potter Stewart).
The following examples illustrate some of the problems with irritability in our current DSM-IV nosology:
• During the initial evaluation of a 9-year-old boy, his parents report that he becomes very irritable and angry, hitting them and throwing objects, not always in reaction to being asked to do something. In particular, they describe one week where he had several multihour "rages" at home, had trouble falling asleep, could not focus on anything, was talking very loudly, and acted as though his parents had no authority over him. However, this irritability did not last 24-7 during that week, as there were some interspersed half days when he was without irritability or other impairment.
• A 10-year-old girl's teachers are concerned about her frequent irritability, lack of paying attention, distractibility, and physical restlessness. Her academic performance has declined recently, but they are not aware of any changes or stress in her family or in her peer group. Her parents report that school has become increasingly difficult with each grade level. They also note that for the past 2 months, she has become afraid of going to sleep in her room alone and seems on edge.
• Parents have brought their 7-year-old boy for evaluation, reporting that he "has been irritable and grouchy since he was in the womb." He was expelled from several preschools/daycare centers because he was irritable and aggressive, and most recently he was suspended from school because he hit another child. They have tried "everything," including therapy and medications, but "nothing works."
Since DSM-IV was first published in 1994, many have worked to advance what is known about irritability in children. For example, to promote research about diagnostic dilemmas in pediatric bipolar disorder (BD), Leibenluft et al. proposed criteria for potential phenotypes of pediatric BD. Two main areas these criteria targeted were: 1) whether a manic episode's "A" mood criteria should be irritable versus elevated/expansive (euphoric) mood; and 2) whether pediatric BD is a distinctly episodic illness (with manic episodes lasting 7 or more days) or more of a chronic illness, with mood fluctuations occurring daily.
At one extreme, "narrow phenotype" criteria included children with distinct episodes of euphoric mania plus at least three "B" symptoms lasting 7 or more days for mania (4-7 days for hypomania). Thus, the narrow phenotype was more stringent than DSM-IV because while mania could involve both euphoria and irritability, only euphoria counted towards mania. At the other extreme, criteria were operationalized for a potential broad phenotype of pediatric BD, also known as "severe mood dysregulation" (SMD). SMD included a chronic, nonepisodic course of functionally-impairing irritability, hyperarousal symptoms of ADHD, and abnormal mood (including anger or sadness) present at least half of the day on most days. Moreover, unlike DSM-IV, SMD criteria defined irritability from an affective neuroscience perspective as "markedly increased reactivity to negative emotional stimuli manifesting verbally or behaviorally (e.g., temper tantrums disproportionate to the inciting event or child's developmental level)" (Leibenluft et al. 2003).
Research using these definitions has greatly advanced our understanding of the phenomenology and pathophysiology of pediatric BD and irritability. For example, studies suggest that SMD defines a common (estimated prevalence 3%), functionally- disabling syndrome. Moreover, a post hoc analysis of the Great Smoky Mountain Study suggests that those meeting SMD criteria as children were at elevated risk for unipolar depression as young adults (Brotman et al. 2006).
The proposed changes in DSM-5 are clearly influenced by this upsurge in research about irritability. For example, to address ongoing controversies in pediatric (and adult) BD regarding the temporal quality of a manic episode, DSM-5 proposes to adopt the "most of the day, nearly everyday" language from the DSM-IV definition of a major depressive episode to now define a manic episode. Also related to pediatric BD, DSM-5 proposes a new diagnosis called Temper Dysregulation Disorder with Dysphoria (TDDD). "T-triple- D" criteria are built largely on Leibenluft's SMD criteria and resultant research, but unlike SMD, TDDD does not include hyperarousal symptoms due to concern about overlap with ADHD. Also, the name emphasizes developmentally inappropriate temper tantrums, rather than a mood component.
DSM-5 also proposes changes to the ODD diagnostic criteria to reflect data showing that ODD is not just a behavioral disorder, but also has mood and emotional components (Nock et al. 2007; Stringaris et al. 2010). Whereas DSM-IV defines ODD as "a pattern of negativistic, hostile, and defiant behavior," the DSM-5 draft defines ODD as a "persistent pattern of angry and irritable mood along with vindictive behavior." Whereas DSM-IV implies, but does not mention, irritability, DSM-5 would include three symptom clusters, one of which is "angry/irritable mood" - defined as "loses temper, is touchy/easily annoyed by others, and is angry/resentful".
Currently, we do not know which of these or other proposed changes will make the final cut before DSM-5 goes to press in May 2013. Yet, one thing is certain: the process of clinically relevant research driving nosology, and vice versa, has ensured that irritability will no longer be one of psychiatry's "elephants in the room," omnipresent but unacknowledged.
Dan P. Dickstein, M.D. is Director, Pediatric Mood, Imaging, & NeuroDevelopment [PediMIND] Program, EP Bradley Hospital and Assistant Professor (Research), Department of Psychiatry & Human Behavior, and Assistant Professor (Research), Department of Pediatrics at the Warren Alpert School of Medicine, Brown University.
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Brotman MA, Schmajuk M, Rich BA, Dickstein DP, et al.: Prevalence, clinical correlates, and longitudinal course of severe mood dysregulation in children. Biol Psychiatry 2006; 60:991-997.
Leibenluft E, Charney DS, Towbin KE, et al.: Defining clinical phenotypes of juvenile mania. Am J Psychiatry 2003; 160:430-437.
Nock MK, Kazdin AE, Hiripi E, et al.: Lifetime prevalence, correlates, and persistence of oppositional defiant disorder: Results from the National Comorbidity Survey Replication. J Child Psychol Psychiatry 2007; 48:703-713.
Stringaris A, Maughan B, Goodman R: What's in a disruptive disorder? Temperamental antecedents of oppositional defiant disorder: Findings from the Avon longitudinal study. J Am Acad Child Adolesc Psychiatry 2010; 49:474-483.