اختلال انفجاری متناوب: ارتباط ابتلا به اختلال استرس پس از حادثه و سایر اختلالات محور I در یک نمونه کهنه نظامی آمریکا

This study examined the prevalence of intermittent explosive disorder (IED) and its associations with trauma exposure, posttraumatic stress disorder (PTSD), and other psychiatric diagnoses in a sample of trauma-exposed veterans (n = 232) with a high prevalence of PTSD. Structural associations between IED and latent dimensions of internalizing and externalizing psychopathology were also modeled to examine the location of IED within this influential structure. Twenty-four percent of the sample met criteria for a lifetime IED diagnosis and those with the diagnosis were more likely to meet criteria for lifetime PTSD than those without (30.3% vs. 14.3% respectively). Furthermore, regression analyses revealed lifetime PTSD severity to be a significant predictor of IED severity after controlling for combat, trauma exposure, and age. Finally, confirmatory factor analysis revealed significant cross-loadings of IED on both the externalizing and distress dimensions of psychopathology, suggesting that the association between IED and other psychiatric disorders may reflect underlying tendencies toward impulsivity and aggression and generalized distress and negative emotionality, respectively.

Intermittent explosive disorder (IED) is defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; American Psychiatric Association [APA], 1994) as an impulse control disorder characterized by recurrent, discrete episodes of aggression that result in assaults against others or the destruction of property. By definition, the intensity of the aggressive behavior is grossly out of proportion to any psychosocial precipitant and the aggressive episodes may not be better accounted for by other mental disorders such as major depressive (MDD), borderline personality (BPD) or mania/hypomania. The diagnosis of IED was first introduced into the nomenclature in DSM-III (American Psychiatric Association, 1980). Originally, the diagnosis was ruled out in the presence of generalized aggression or impulsivity between “aggressive episodes” or if a diagnosis of antisocial personality disorder (ASPD) applied. The DSM-III-R (American Psychiatric Association, 1987) added an additional rule-out for BPD. In DSM-IV these rule-outs were eliminated and the exclusion criteria changed to: “aggressive episodes are not better accounted for by another disorder” (American Psychiatric Association, 1994, p. 612). Finally, DSM-5 (American Psychiatric Association, 2013) brought IED together with other disorders characterized by problems with self-control into a new chapter, “Disruptive, Impulse-Control and Conduct Disorders.” The DSM-5 IED criteria addressed important limitations in prior versions of the IED diagnostic criteria, including changes to the type of aggression that can be considered for the diagnosis; it allows for both verbal and non-destructive/non-injurious physical aggression, in addition to the serious assaultive or destructive aggression required in DSM-IV. DSM-5 also provides specific frequency and timeframe requirements, and requires marked distress in the individual or functional impairment. Finally, the relationship of IED to frequently comorbid disorders has been clarified; a diagnosis can be given in the presence of attention-deficit/hyperactivity disorder, conduct disorder, and/or oppositional defiant disorder when the aggressive episodes are in excess of those usually seen in those disorders and merit independent clinical attention (American Psychiatric Association, 2013). DSM-IV lifetime IED prevalence in the National Comorbidity Survey Replication sample (Kessler et al., 2006) was estimated at 7.3%. In that study, individuals with IED reported an average of 43 episodes of explosive behavior over their lifetimes, resulting in an estimated $1300 or more in total property damage. The sociodemographic correlates of IED have been fairly consistent across studies and include a mean onset at 15 years of age, duration of 20 years, and a higher prevalence among men than women (ratio of 3:1; Coccaro, 2000). In addition, IED has been shown to exert deleterious effects on job performance and health, and has been linked to coronary heart disease (McCloskey, Kleabir, Berman, Chen & Coccaro, 2010). IED is often accompanied by comorbid diagnoses; studies have found high frequencies of co-occurring mood (76–93%), anxiety (48–78%), and substance use disorders (48–60%; Coccaro, Posternak & Zimmerman, 2005; McElroy, Soutullo, Beckman, Taylor & Keck, 1998). In addition, evidence suggests links to trauma exposure and PTSD. For example, in a nationally representative sample of South African adults, Fincham et al. (2009) found an association between exposure to multiple traumatic life events and IED. Similarly, Nickerson, Aderka, Bryant, and Hoffman, 2012 examined the correlates of IED in trauma-exposed and non-trauma-exposed civilians and found IED was associated with greater trauma exposure and PTSD. Indirect support for a possible link between trauma, PTSD and IED comes from an extensive body of research documenting associations between PTSD and problems with anger and aggression among combat veterans (for review, see McHugh, Forbes, Bates, Hopwood, & Creamer, 2012) and among veterans with combat-related PTSD, specifically (Lasko, Gurvits, Kuhne, Orr, & Pitman, 1994). One possible explanation for the substantial psychiatric comorbidity associated with IED is that IED and accompanying disorders are manifestations of a common underlying factor. Factor analytic studies suggest that an externalizing dimension (EXT) accounts for common variance across substance use disorders and ASPD while an internalizing dimension (INT) accounts for common variance across unipolar mood, anxiety, and somatiziation disorders (see Krueger, Capsi, Moffitt & Silva, 1998; Krueger, McGue & Iacono, 2001). In several studies, the INT dimension is further divided into two correlated factors termed “anxious–misery” or “distress” (comprised of unipolar depression, dysthymia, GAD) and “fear” (comprised of panic and phobic disorders; Cox, Clara, & Enns, 2002; Krueger, 1999, Slade and Watson, 2006 and Vollebergh et al., 2001). This model has been replicated across a range of populations, including samples of veterans with a high prevalence of PTSD (Miller, Fogler, Wolf, Kaloupek & Keane, 2012; Miller et al., 2012). To our knowledge, no study has specifically examined the location of IED within this model. The existing literature suggests that the aggression and impulsivity associated with IED and its demonstrated links with substance abuse (Coccaro et al., 2005) may align primarily with EXT. Alternatively, evidence for an association with generalized anxiety disorder and depression (Nickerson et al., 2012) suggests it might also show an additional association with INT (a cross-loading on EXT and INT).