Intermittent Explosive Disorder

Intermittent explosive disorder (IED) is recurrent behavioural outbursts with failure to control aggressive impulses (verbal aggression twice weekly for 3 months, or three damaging or injurious outbursts in 12 months) grossly out of proportion to provocation.

• Lifetime prevalence 2 to 4%, onset in late childhood to adolescence, males more often.
• Serotonin deficiency, amygdala hyperreactivity, prefrontal hypoactivity; risk factors: childhood abuse, family violence, head injury.
• Comorbid depression, anxiety, substance misuse, ADHD, personality disorders.
• Consequences: legal problems, job loss, relationship breakdown, injury.

• Sudden impulsive (not premeditated) aggression with tension or arousal beforehand, followed by relief then remorse or regret.
• Verbal tirades, assault, property damage, road rage.
• Interval between episodes with normal behaviour; irritability.

• DSM-5 criteria; Overt Aggression Scale, Buss-Perry Aggression Questionnaire.
• Exclude conduct disorder, antisocial or borderline personality disorder, mania, psychosis, substance intoxication, ADHD, PTSD, epilepsy, brain injury and tumours, dementia, medications (steroids, anabolic steroids, stimulants).
• MRI brain, EEG, thyroid, testosterone if appropriate; toxicology.
• Risk assessment for violence and domestic abuse; safeguarding.

• Cognitive behavioural therapy with relaxation, cognitive restructuring and coping skills training (12 to 16 sessions) is first line.
• Medication: SSRIs fluoxetine 20 to 60 mg daily (reduces aggression), sertraline 50 to 200 mg; add mood stabilisers for refractory disease: lithium 600 to 1200 mg (level 0.6 to 1.0), valproate 500 to 1500 mg, carbamazepine 200 to 800 mg, or topiramate 100 to 200 mg.
• Beta blockers (propranolol 40 to 160 mg) or antipsychotics (risperidone 1 to 3 mg) for severe dyscontrol.
• Treat comorbid substance use, ADHD, trauma.
• Safety planning, legal advice, anger management groups.