Habituation and Sensitization Processes in Depressive Disorders

Abstract

The aim of the present study was to investigate further into habituation and sensitization processes in depressive disorders. The depressive subjects were 27 outpatients. All of them were diagnosed according to DSM-III-R criteria. Controls were 27 normal subjects. The amplitudes of electrodermal responses and the basal levels were recorded during a stimuli series of 15 80-dB tones and of 1 100-dB tone in the 11th trial. The depressive patients displayed lower basal conductance levels and lower conductance amplitudes in orienting responses to the first stimulus and to stimulus change. No differences were found in conductance response amplitudes of stimuli series, although a tendency towards smaller conductance amplitudes in depressive patients was observed before stimulus change. A trend towards habituation was detected in both groups, but no differences between them were present, neither the habituation velocity of depressives was found to be unlike normals. Our results display lower responsivity in depressive patients, which reflects alterations in the sensitization process.

Effect of Acute Ketamine Treatment on Sympathetic Regulation Indexed by Electrodermal Activity in Adolescent Major Depression

“…These findings point to a negative relationship between the severity of depressive symptoms and EDA parameters before acute ketamine treatment. Our results are in accordance with other studies revealing lower SCL values in subjects with more severe depressive symptoms [ 82 , 83 , 84 , 85 , 86 , 87 ]. In other words, MDD patients with more pronounced, subjectively interpreted depressive symptoms had lower tonic EDA activity before ketamine treatment that appeared to improve (no significant correlations between EDA and depressive symptoms) after the acute ketamine intervention.…”

The association between electrodermal activity (EDA), depression and suicidal behaviour: A systematic review and narrative synthesis

“…The overall efficiency of SCR as a means of discriminating between depressed and healthy subjects has been estimated to be about 80% [ 43 ]. It has also been reported that depressed patients show marginally faster habituation of the skin resistance orienting response than healthy controls [ 44 , 45 ], although one study [ 35 ] with a lower NOS score than the others (2 vs. 3 and 5) did not find this.…”

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

“…However, differences in suicide rates between in‐patients and out‐patients could depend on differences in the severity of the depression (42). Inverse relationships between observations at the continuous scale of electrodermal habituation scores and the total scores of depression rating scales have in fact been reported in depressed patients (15, 43). However, on the other hand, the present study reports that the CPRS scores did not differ significantly between hyporeactives and the reactives in Thorell’s material (4) which is in accord with the absence of a significant relationship between habituation scores and Beck Depression Inventory (33) scores, reported before (10).…”