Suicidal subtypes, stress responsivity and impulsive aggression

Abstract

While prominent models of suicidal behavior emphasize the hypothalamic-pituitary-adrenal (HPA) axis dysregulation, studies examining its role have yielded contradictory results. One possible explanation is that suicide attempters are a heterogeneous group and HPA axis dysregulation plays a more important role only in a subset of suicidal individuals. HPA axis dysregulation also plays a role in impulsivity and aggression. We hypothesize subgroups of attempters, based on levels of impulsivity and aggression, will differ in HPA axis dysregulation. We examined baseline cortisol, total cortisol output, and cortisol reactivity in mood disordered suicide attempters (N = 35) and non-attempters (N = 37) during the Trier Social Stress Test. Suicide attempters were divided into four subgroups: low aggression/low impulsivity, high aggression/low impulsivity, low aggression/high impulsivity, and high aggression/high impulsivity. As hypothesized, attempters and non-attempters did not differ in any cortisol measures while stress response differed based on impulsivity/aggression levels in suicide attempters, and when compared to non-attempters. Specifically, attempters with high impulsive aggression had a more pronounced cortisol response compared with other groups. This is the first study to examine the relationship between cortisol response and suicidal behavior in impulsive aggressive subgroups of attempters. These findings may help to identify a stress responsive suicidal subtype of individuals.

The Involvement of Hypothalamus–Pituitary–Adrenal (HPA) Axis in Suicide Risk

“…Their findings suggested that peer stress acts as a trigger for suicidal ideation among female youths, but only among those with blunted cortisol reactivity [ 41 ]. Recently, Stanley and colleagues [ 42 ] hypothesized that different subgroups of those who have attempted suicide may differ in HPA axis dysregulation. They explored baseline cortisol, total cortisol output, and cortisol reactivity in participants who had both a mood disorder and a suicide attempt history ( N = 35) and those with a suicide attempt history ( N = 37) during the TSST.…”

“…They explored baseline cortisol, total cortisol output, and cortisol reactivity in participants who had both a mood disorder and a suicide attempt history ( N = 35) and those with a suicide attempt history ( N = 37) during the TSST. Specifically, those in the attempt group with higher impulsive aggression had a more pronounced cortisol response compared with other groups [ 42 ]. Additionally, Rizk and coworkers [ 43 ], in a sample of thirty-five individuals with major depressive disorder and 23 healthy controls, reported that individuals with brief, limited suicidal ideation (SI) are more stress-responsive (in the context of the TSST) than those with longer/continuous ideation.…”

Suicide Risk and Addiction: The Impact of Alcohol and Opioid Use Disorders

“…Dysfunction of the biological stress response as suggested by hyperactive hypothalamic-pituitary-adrenal (HPA) axis responses has been evinced in both heavy alcohol users [ 88 – 90 ] and suicidal individuals [ 91 ] alike. Specifically, a subtype of suicide attempters high in trait impulsivity and aggression exhibited heightened cortisol responses to a lab-induced social stressor, compared to suicide attempters low on either aggression, impulsivity, or both [ 92 , 93 ]. Hyperactive cortisol responses have also been demonstrated in individuals with major depression [ 71 ], particularly in relation to symptoms of psychomotor agitation [ 94 ], and in individuals with highly variable patterns of suicidal ideation compared to those with stable suicidal thoughts [ 95 ].…”

Depressive symptoms as a mediator between impulsiveness and suicidal ideation among Chinese medical college students

“…In the present study, we analysed three variables together with a correlation matrix and regression method, and all of the variables were included. In many previous studies, one of the variables was regarded as a group (36, [54][55][56][57]. A predictive model built to include impulsive personality, depressive symptoms and suicidal ideation shows that impulsive personality and depressive symptoms can explain the variance of suicidal ideation independently, but this model does not mention the correlation between impulsiveness and depressive symptoms (58).…”