Depressed inpatients, electrodermal reactivity, and suicide - a study about psychophysiology of suicidal behavior

Abstract

This study deals with the psychophysiological (electrodermal reactivity in a habituation experiment, habituation score) basis of suicidal behaviour. It shows habituation data of 30 suicides with violent method compared to age-and sex-matched control groups with different suicidal expressions, on a large database of a total sample of 504 depressed inpatients.The major finding of a significantly reduced electrodermal reactivity (habituation score) in suicidal action versus suicidal thinking confirms early results but in a comprehensive large sample. Also, it confirms our clinical hypothesis of a biological basis of suicidal action, specially in suicidal acts with violent methods.

Valid electrodermal hyporeactivity for depressive suicidal propensity offers links to cognitive theory

“…Publications concerning ‘electrodermal activity’, ‘suicide’, ‘suicide attempt’ and ‘depression’ were searched in PubMed and PsychINFO and through references from 66 known publications within the field of electrodermal activity in depression since 1890. There were 31 available reports in electrodermal suicidology (3–31).…”

“…Those reports were selected in a first step that addressed the habituation of the electrodermal response to simple tone stimuli in depressed patients. Excluding on the present issue less focused and closely interrelated reports as a second step, ten studies from 1986 to 2007 remained (3–12) and described in Tables 1–2.…”

“…Two independent Swedish studies (3, 4) found that electrodermal hyporeactivity was related to the occurrence of suicide or suicide attempt, particularly in depressed patients (4). These studies were followed by a series of publications on electrodermal reactivity and suicidal behavior (5–11) by the German group around Wolfersdorf and Straub from an over many years consecutively growing, highly valuable material that in 2006 had grown to more than 650 depressive patients (12). The statistical significance of the relationship between electrodermal hyporeactivity and the occurrence of suicide or suicide attempt has, however, varied widely, from being non‐significant (6, 7, 10), significant (5, 8, 9) to highly significant (4, 11, see Fig.…”

Capable of Suicide: A Functional Model of the Acquired Capability Component of the Interpersonal-Psychological Theory of Suicide

“…The second potential biological vulnerability for development of the capability for suicide involves the rate at which individuals habituate at the neurobiological level. Research has demonstrated that individuals with a history of a suicide attempt, particularly violent attempts, and those who later died by suicide exhibit faster rates of basic physiological habituation during a tone stimuli noise task (Edman, Asberg, Levander, & Schalling, 1986; Wolfersdorf, Straub, Barg, Keller, & Kaschka, 1999). Such quicker acting habituation processes may be problematic as even minor diathesis‐expressing life experiences (e.g., playing contact sports or non‐life‐threatening accidental injury) may greatly facilitate the habituation to fear and pain.…”

EUDOR-A multi-centre research program: A naturalistic, European Multi-centre Clinical study of EDOR Test in adult patients with primary depression

“…A trend to a faster habituation in suicidal attempters and completers who have used violent methods was also confirmed by Keller et al [18] and Wolfersdorf & Straub [19]. Differently, Jandl et al [20] found no difference between violent and non-violent suicide attempters, even if suicide attempters were significantly more hyporeactive than non-attempters.…”