Validity of the new A1 and A2 criteria for DSM-5 intermittent explosive disorder.

A disorder of impulsive aggression has been in the Diagnostic and Statistical Manual for Mental Disorders (DSM) since the first edition. In DSM-III, this disorder was codified as Intermittent Explosive Disorder (IED) and was thought to be rare. However, DSM criteria for IED were poorly operationalized and empiric research in IED was limited until the past decade when research criteria were developed. Subsequently, renewed interest in disorders of impulsive aggression led to a recent series of community based studies that have now documented IED to be as common as many other psychiatric disorders. Recent research indicates that the core of IED (A criteria) can be captured with new criteria that identify high frequency/low intensity aggressive outbursts (A1) and low frequency/hi intensity outbursts (A2). This paper presents new data regarding the phenomenology, comorbidity/life course of IED as a function of A1 and A2 criteria. Together with reanalysis of previously published data regarding family history, biomarkers, and treatment response in individuals with recurrent, problematic, impulsive aggression, these data provide empirical support for both A1 and A2 criteria for DSM-5 IED.