Review of: Deutz MH et al, J Am Acad Adolesc Psychiatry 2019;58(6):589–599

Can we use heart rate to assess and track psychopathology? Child psychiatrists associate lower resting heart rate (HR-rest) and heart rate reactivity (HR-reactivity) with externalizing behaviors such as disruptive behaviors and aggression (“under-arousal”) and elevations with internalizing problems such as anxiety (“over-arousal”). The transdiagnostic approach of the NIH Research Diagnostic Criteria (RDoC) offers research linking heart rate with emotional dysregulation. This study bridges these ideas to clinical practice.

In this Canadian study, the authors explored how HR-rest and HR-reactivity relate to dysregulation: 182 clinically referred children (75.8% boys) between 8 and 12 years old underwent heart rate monitoring at rest and during a computerized go/no-go task. 24.2% of children were on psychotropic medications, mostly stimulants. Dysregulation was measured from sub-scale scores on the clinically ubiquitous Child Behavior Checklist, specifically the Dysregulation Profile (CBCL-DP), which itself is intricately related to the CBCL Anxious/Depressed, Aggression, and Attention Problems subscales.

These researchers found that higher resting heart rate correlated with higher scores on the dysregulation and aggression subscales, but not for anxiety/depression or attention problems. Heart rate reactivity was not correlated to any of these scales. Although males were more likely to have elevated dysregulation and aggression scores, there was no link between gender and resting heart rate and reactivity.

The researchers also used a person-centered approach, in which subgroups with similar profiles were identified. This approach found that patients tended to sort into 3 symptom-profile groups: normative (n = 92), predominantly aggressive (n = 69), and dysregulated (n = 14). The dysregulated group had the highest scores (more symptomatic) for anxiety/depression, aggression, and attention problems. When the researchers mapped heart rate parameters onto these profiles, they found that youth in the predominantly aggressive group had higher HR-rest. In contrast, youth in the dysregulated group did not have elevated HR-rest but did have elevated HR-reactivity.

CCPR’S Take
Given the variability among people and confounding variables such as past trauma, it is difficult to apply these findings directly to individual patients. Still, with most of the heart rate literature focused on callous unemotional traits, this study reinforces the importance of looking beyond the categorical descriptors of the DSM and toward a more biologically informed approach. One day, perhaps we will be able to use simple physiological measures to help differentiate categories of diagnoses as well as alert us to patients who may have more propensity for aggression.