Overview
Intermittent Explosive Disorder (IED) stands as a perplexing and often misunderstood psychiatric condition characterized by recurrent, impulsive outbursts of verbal or physical aggression disproportionate to the provocation. These outbursts often result in significant distress or impairment in social, occupational, or other important areas of functioning. Understanding the underlying causes and risk factors of IEDs is crucial for effective management and intervention.
Research into the aetiology of IED suggests a multifaceted interplay of biological, environmental, psychological, sociocultural, and developmental factors. Biological studies have revealed genetic predispositions, neurobiological abnormalities, and imbalances in neurotransmitter systems, implicating complex neurobiological mechanisms in the manifestation of IED. Environmental influences, such as childhood trauma, exposure to violence, and chronic stressors, have also been linked to the development of this disorder.
Psychological factors, including co-occurring mental health disorders and maladaptive coping strategies, contribute significantly to the expression and severity of IED symptoms. Moreover, sociocultural norms and developmental experiences shape the expression of anger and aggression, further influencing the development of this disorder.
Causes
Childhood trauma and stressful life events
Childhood trauma and stressful life events constitute significant contributors to the development of IEDs. Experiences of abuse, neglect, or witnessing violence during formative years can profoundly impact emotional regulation and coping mechanisms, laying the groundwork for explosive outbursts later in life. Studies have demonstrated a clear correlation between adverse childhood experiences (ACEs) and the risk of developing IED, highlighting the lasting effects of early trauma on behavioural and psychological functioning.1
Moreover, ongoing exposure to stressors, such as financial instability, relationship conflicts, or work-related pressures, can exacerbate underlying vulnerabilities and trigger impulsive aggression in individuals predisposed to IED. The cumulative effect of chronic stressors further disrupts neurobiological processes involved in emotion regulation, amplifying the risk of explosive reactions to minor provocations.
Recognizing the pivotal role of childhood trauma and ongoing stressors in the aetiology of IED underscores the importance of early intervention and trauma-informed care approaches in mitigating the long-term impact of adverse experiences on mental health outcomes.
Genetics, brain abnormalities and neurotransmitters
In exploring the roots of IED, genetic predispositions, brain abnormalities, and neurotransmitter imbalances emerge as pivotal factors. Genetic studies have unveiled hereditary links, suggesting that certain individuals may inherit a susceptibility to IED from their ancestors.2
Additionally, neurobiological research has identified structural and functional abnormalities in key brain regions associated with emotional regulation and impulse control, such as the prefrontal cortex and amygdala.3 These anomalies may disrupt neural circuits responsible for modulating aggression and result in the dysregulation observed in individuals with IEDs. Furthermore, disturbances in neurotransmitter systems, particularly serotonin and dopamine, are crucial in mediating emotional responses and behaviour. Dysfunctions in these systems can contribute to heightened irritability, impulsivity, and explosive outbursts characteristic of IED. Understanding the intricate interplay between genetics, brain abnormalities, and neurotransmitters provides valuable insights into the pathophysiology of IED and underscores the importance of multidimensional approaches in its diagnosis and treatment.
Risk factors
Sociocultural
Sociocultural factors play a pivotal role in shaping the expression and exacerbation of IEDs. Cultural norms regarding the acceptability and expression of anger and aggression influence how individuals perceive and regulate their emotions. In societies where aggressive behaviour is normalized or even encouraged, individuals with predispositions to IED may find fewer inhibitions against acting out impulsively.4
Moreover, socioeconomic disparities, discrimination, and exposure to violence in marginalized communities can heighten stress levels and exacerbate feelings of anger and frustration, contributing to the development of IEDs.5 Furthermore, societal attitudes towards mental health and seeking help can impact the accessibility and utilization of appropriate interventions for individuals struggling with IEDs. Recognizing the influence of sociocultural factors is essential for developing culturally sensitive prevention and intervention strategies that address the unique challenges faced by individuals affected by IEDs within diverse communities
Psychological
Psychological risk factors play a pivotal role in the development and exacerbation of IEDs. Individuals with IEDs often exhibit maladaptive patterns of thinking, feeling, and behaving that contribute to the explosive outbursts characteristic of the disorder. Common psychological risk factors include impulsivity, difficulty regulating emotions, and a heightened sensitivity to perceived threats or provocations. Moreover, individuals with IEDs frequently experience cognitive distortions, such as black-and-white thinking or catastrophizing, which fuel their anger and aggression.6 Co-occurring mental health disorders, such as depression, anxiety, or personality disorders, also elevate the risk of IEDs.7
Understanding these psychological risk factors is essential for clinicians to tailor interventions that address underlying cognitive and emotional processes, ultimately promoting better management and treatment outcomes for individuals living with IEDs.
Summary
The causes and risk factors of Intermittent Explosive Disorder (IED) are multifaceted and complex, encompassing biological, environmental, psychological, sociocultural, and developmental influences. Biological factors, including genetic predispositions, neurobiological abnormalities, and imbalances in neurotransmitter systems, contribute to the underlying neurobiology of IED. Environmental influences, such as childhood trauma, exposure to violence, and chronic stressors, play a significant role in shaping behaviour and emotional regulation. Psychological risk factors, such as impulsivity, difficulty regulating emotions, cognitive distortions, and co-occurring mental health disorders, contribute to the expression and severity of IED symptoms.
Also, sociocultural norms regarding the expression of anger and aggression, as well as developmental experiences, influence the trajectory of IED from childhood to adulthood. Identifying these causes and risk factors is essential for early intervention, prevention, and tailored treatment approaches. By understanding the intricate interplay of these factors, clinicians, researchers, and policymakers can develop more targeted strategies to address the root causes of IEDs and provide effective support for individuals affected by this debilitating disorder.
References
- Nickerson A, Aderka IM, Bryant RA, Hofmann SG. The relationship between childhood exposure to trauma and intermittent explosive disorder. Psychiatry Research. 2012 May;197(1-2):128–34.
- Coccaro EF. A family history study of intermittent explosive disorder. Journal of Psychiatric Research. 2010 Nov;44(15):1101–5.
- Coccaro EF, Fitzgerald DA, Lee R, McCloskey M, Phan KL. Frontolimbic Morphometric Abnormalities in Intermittent Explosive Disorder and Aggression. Biological Psychiatry: Cognitive Neuroscience and Neuroimaging. 2016 Jan;1(1):32–8.
- Coccaro EF, Fanning JR, Keedy SK, Lee RJ. Social cognition in Intermittent Explosive Disorder and aggression. Journal of Psychiatric Research. 2016 Dec;83:140–50.
- Steakley-Freeman DM, Lee RJ, McCloskey MS, Coccaro EF. Social desirability, deceptive reporting, and awareness of problematic aggression in intermittent explosive disorder compared with non-aggressive healthy and psychiatric controls. Psychiatry Research. 2018 Dec;270:20–5.
- Coccaro EF, Lee R, McCloskey MS. Relationship between psychopathy, aggression, anger, impulsivity, and intermittent explosive disorder. Aggressive Behavior. 2014 Apr 23;40(6):526–36.
- Galbraith T, Carliner H, Keyes KM, McLaughlin KA, McCloskey MS, Heimberg RG. The co-occurrence and correlates of anxiety disorders among adolescents with intermittent explosive disorder. Aggressive Behavior. 2018 Jul 24;44(6):581–90.