Irritability in Pediatric Mania and Other Childhood Psychopathology

Abstract

Irritability is an important symptom in childhood psychopathology that has received relatively little research attention. Recent controversy concerning the diagnosis of mania in children has focused attention on how little is known about how to assess irritability in a systematic way, and about its diagnostic associations. For example, subtyping irritability according to course (chronic vs. episodic), precipitants, and family history may facilitate the identification of psychopathology and the study of pathophysiology. While normative and pathologic irritability can be differentiated reliably, the validity of the distinction is unclear. In addition, there is a need for scales designed to measure the severity of irritability in children with mood and anxiety disorders. In order to facilitate research, we propose a definition of irritability from the perspective of affective neuroscience. Because reactive aggression may be a helpful animal model for irritability, we review the neural circuitry mediating this behavior. Behavioral paradigms that evoke frustration, as well as those that assess the ability to inhibit a prepotent motor response, maintain attentional focus, execute response reversal, recognize angry faces, and regulate emotional responses, may be useful in the study of irritability. Examples of such paradigms are described, and the pharmacology of irritability is reviewed briefly.

Neural Circuitry Engaged During Unsuccessful Motor Inhibition in Pediatric Bipolar Disorder

“…In adults with BPD, impulsivity is frequently associated with risky behavior such as substance abuse, present in 60% of adults with BPD (47). In children with BPD, impulsivity is associated with irritability, and both are impairing across mood states (48). Data in control children suggest that irritability and decreased motor inhibition may be related mechanistically: in controls, impaired motor inhibition (i.e., increased SSRT) is associated with increased intensity of experienced anger (49).…”

“…Deficits in motor inhibition might produce symptoms of impulsivity and affective aggression in pediatric BPD (1,2) while also contributing to diagnostic confusion between attention deficit hyperactivity disorder (ADHD) and BPD (3). The neural circuitry engaged during unsuccessful motor inhibition in pediatric bipolar disorder (BPD) is therefore of interest.…”

The behavioral actions of lithium in rodent models: Leads to develop novel therapeutics

“…Instrumental aggression, unlike its explosive counterpart, is often unassociated with emotion or later feelings of guilt (Cornell et al, 1996). Different disorders are associated with the different subtypes; for example, instrumental aggression and psychopathy have been associated with one another (Cornell et al, 1996), whereas increased risk for childhood bipolar disorder or explosive disorder is associated with impulsive aggression alone (Coccaro, 1998;Leibenluft et al, 2003). The two kinds of aggression respond differently to pharmacological treatment, and appear to have different neural substrates (see (Blair, 2005) for a concise review).…”

“…Though much is known about certain forms of aggression and related neural systems, no single biochemical origin or pathway can be looked to when attempting to discover the origin of aggressive behavior. Owing to the vast array of psychiatric disorders within which aggression is manifested, attempts are now being made to treat not merely the aggressive behavior, but the underlying disorder/disease process of which the behavior is a symptom (Connor and Steingard, 1996;Leibenluft et al, 2003).…”

Loss of Temper and Irritability: The Relationship to Tantrums in a Community and Clinical Sample

“…The defining feature of DMDD is frequently occurring verbal or physical outbursts greatly out of proportion to the precipitant, with mood between the outbursts being persistently irritable and angry and noticeable by others. Like its forbear, severe mood dysregulation (Leibenluft et al 2003), DMDD's definition implies that it is possible to have outbursts without an intervening negative mood. That is something one certainly hears from parents who say, ''My child is perfectly happy so long as he gets his way.''…”