Response prediction to antidepressants using scalp and source-localized loudness dependence of auditory evoked potential (LDAEP) slopes.
The loudness-dependence of the auditory evoked potential (LDAEP) slope may be inversely related to serotonin (5-HT) neurotransmission. Thus, steep LDAEPs tend to predict a positive response to selective serotonin reuptake inhibitor (SSRI) antidepressants, which augment 5-HT. However, LDAEPs also predict outcome to antidepressants indirectly altering 5-HT (e.g. bupropion). Hence, the LDAEP's predicative specificity and sensitivity to antidepressant response/outcome remains elusive. Scalp N1, P2 and N1/P2 LDAEP slopes and standardized low resolution brain electromagnetic tomography (sLORETA)-localized N1 and P2 LDAEP slopes were assessed in depressed individuals (N=51) at baseline, 1 and 12 weeks post-treatment with one of three antidepressant regimens [escitalopram (ESC)+bupropion (BUP), ESC or BUP]. Clinical response was greatest with ESC+BUP at week 1. Treatment responders had steep N1 sLORETA-LDAEP baseline slopes while non-responders had shallow ones. P2 sLORETA-LDAEP slope increases at 1 week existed in responders; decreases were noted in non-responders. Exploratory analyses indicated that more BUP and ESC responders versus non-responders had steep baseline N1 sLORETA-LDAEP slopes. Additionally, slight decreases in scalp P2 LDAEP by week 1 existed for ESC treatment, while slope increases existed with ESC+BUP treatment. Only baseline N1 sLORETA-LDAEP discriminated treatment responders/non-responders. This work confirms that certain LDAEP measures are associated with treatment outcome and appear to be differentially modulated with varying antidepressant drug regimens, though this should be confirmed using larger samples.
University of Ottawa Institute of Mental Health Research, Ottawa, ON, Canada. jaworskn@ucalgary.ca
Natalia
N
Jaworska
Claude
C
Blondeau
Pierre
P
Tessier
Sandhaya
S
Norris
Wendy
W
Fusee
Pierre
P
Blier
Verner
V
Knott
D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000928:Antidepressive Agents / Q000627:therapeutic use*; D003865:Major Depressive Disorder / Q000188:drug therapy* / Q000503:physiopathology; D004311:Double-Blind Method; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006801:Humans; D008144:Loudness Perception / Q000187:drug effects* / Q000502:physiology*; D008297:Male; D017063:Outcome Assessment, Health Care; D011237:Predictive Value of Tests; D011569:Psychiatric Status Rating Scales; D011571:Psychoacoustics; D012680:Sensitivity and Specificity; D055815:Young Adult
D000928:Antidepressive Agents