Intermittent Explosive Disorder Tied to Multiple Comorbidities

An analysis of 117.7 million health care records showed that intermittent explosive disorder (IED), characterized by impulsive aggression and poor emotional control, was associated with multiple classes of comorbidities.

Of the 30,000 individuals diagnosed with IED during their lifetime, 95.7% had at least one other psychiatric diagnosis, said Yanli Zhang James, MD, PhD, of the State University of New York Medical Center in Syracuse, and co-authors in JAMA Psychiatry.

All psychiatric subcategories and 92% of psychiatric diagnoses were significantly associated with IED, with hazard ratios (HRs) ranging from 2.1 for substance use disorders to 76.6 for adult personality and conduct disorders.

Neurodegenerative diseases (HR 5.0), epilepsy (HR 4.9), movement disorders (HR 3.1), cerebral palsy (HR 2.6), and sleep disorders (HR 2.2) were the primary neurological conditions associated with IEDs. Obesity (HR 1.6), hyperlipidemia (HR 1.5), hypertension (HR 1.6), and gastroesophageal reflux disease (HR 1.7) were among the major somatic disorders.

Only 0.03% of the total number of patients were diagnosed with IED. “Our findings uniquely shed light on how IEDs are diagnosed in clinical practice differently than in research settings,” Chang-James and colleagues wrote.

Because the analysis relied on diagnosis codes in medical records, the prevalence of IED was “very low in this study compared to community-based studies, which have a prevalence of about 2.5% to 3%,” noted Emil Coccaro, MD, of Ohio. Columbus State University College of Medicine, who was not involved in the research.

This is likely because doctors do not screen for aggression and “rarely use the IED diagnosis; the IED diagnosis is rarely ‘at the top of the priority list,'” he wrote in an email to MedPage Today. “Also, people with aggression problems often do not seek evaluation and treatment for aggression or IED.”

Coccaro noted that IED usually precedes a diagnosis, suggesting that IED or aggression is a risk factor for other diagnoses that emerge later.

He pointed out that “the age of onset of IEDs is in the pre-adolescent years – about 11 years – as reported in epidemiological studies of adolescents.” “The age of onset of other diagnoses is usually later than that.”

Zhang-James and colleagues investigated the prevalence of IED and its comorbidities in matched groups of patients with and without IED in the TriNetX Research Network, which included registries from 87 health care organizations.

The researchers evaluated 30,357 people with at least one IED diagnosis based on ICD-10 codes and 30,357 matched controls. In both groups, 70% were male and the median age at first visit was 26 years.

Among those with IEDs, the prevalence of mood disorders was 60.3%, anxiety disorders 59%, and developmental disorders 44.5%. More than a third of people with IED also had neurological, personality, or other non-psychotic disorders. Attention deficit hyperactivity disorder (ADHD); Or substance abuse disorders.

“The striking finding was that IEDs without psychopathy, so-called pure IEDs, were rare: only 4.3% of those with IEDs had no other psychiatric diagnosis,” Chang-James and co-authors wrote.

They note that the findings raise provocative hypotheses for clinical practice. They suggested that clinicians should consider using IED diagnosis more frequently when necessary. “Highlighting aggression as a separate diagnosis may focus more attention on aggressive behavior and facilitate the development of targeted treatments,” they wrote. “Otherwise, aggressive behavior remains somewhat hidden as a feature within other disorders.”

The researchers noted that the association of IEDs with falls or accidents suggests that impulsiveness may prompt people to seek medical care. “The fact that 34% of ICD codes were significantly associated with IED suggests that impulsivity may be an underestimated risk factor in health care,” they wrote. “Ideally, IED therapy would include teaching thinking skills before acting,” not just targeting aggression.

They added that the relationship between IED and ADHD, which also centers on impulsivity, suggests that early effective treatment for ADHD may reduce the prevalence of IED.

The findings also raise questions about how diagnostic systems are constructed, Chang-James and co-authors said, noting, “It is impossible to know how often IEDs are overlooked versus not given because of clinicians’ judgment that aggression is better explained by another diagnosis.” . “.

Limitations included the study’s reliance on medical records. Low diagnosis rates of IEDs may affect the generalizability of the results.

The researchers recommended that it be validated in future studies, and acknowledged that the data did not provide clues as to why the diagnosis was so rare in clinical practice.