MK4MDD

Genetic/Epigenetic Locus Search Cross Data Search

Study Report

Reference

Citation	Kemp, 2009 PubMed
Full Info	Kemp, A.H., Hopkinson, P.J., Hermens, D.F., Rowe, D.L., Sumich, A.L., Clark, C.R., Drinkenburg, W., Abdi, N., Penrose, R., McFarlane, A. et al. (2009) Fronto-temporal alterations within the first 200 ms during an attentional task distinguish major depression, non-clinical participants with depressed mood and healthy controls: a potential biomarker? Hum Brain Mapp, 30, 602-614.

Study

Hypothesis or Background	Attentional impairment in depression is a cardinal feature of depression and has been proposed as a candidate endophenotype for major depressive disorder. Event-related potentials (ERPs) elicited by oddball signal detection tasks provide objective markers of selective stimulus processing, and are pertinent endophenotypic markers for depression. While previous studies have sought to determine objective markers for attentional impairment in depression, evidence is inconsistent and may involve heterogeneity in relatively small samples.
Sample Information	outpatients with major depressive disorder (MDD; n = 78) and participants with depressed mood (PDM; n = 127) relative to healthy controls (CTL; n = 116)
Method Detail	Here, we brought together oddball ERP recording with source localization of neural correlates of selective attention in outpatients with major depressive disorder (MDD; n = 78) and participants with depressed mood (PDM; n = 127) relative to healthy controls (CTL; n = 116).
Method Keywords	event-related potential (ERP)
Result	The key finding was a dimensional exaggeration of the P200 (140-270 ms) to both target (signal) and non-target (noise) stimuli, most pronounced in MDD, followed by PDM, relative to CTL. This exaggeration was coupled with slower and more variable response times, suggesting that neural systems are attempting to compensate for a difficulty in discriminating signal from noise. P200 alterations were localised to limbic (hippocampal), temporal and ventral prefrontal regions, key components of the signal detection network. A subsequent reduction and delay in the P300 was also revealed for MDD indicating that the pronounced lack of discrimination in clinical depression may also lead to impaired stimulus evaluation.
Conclusions	This P200 increase in depression could provide a potential mechanism for the attentional impairment frequently observed in depression and consequent alterations in the P300 may differentiate clinically significant depression.

Relationships reported by Kemp, 2009

Component A Approved Name (Name in Paper)	Component A Type	Component B Approved Name (Name in Paper)	Component B Type	Statistical Result	Relationship Description	Result Category (Positive/Negative))
temporal prefrontal regions (temporal prefrontal regions)	brain morphology and function	P200 (P200)	neurobiological system		P200 alterations were localised to limbic (hippocampal), temporal and ventral prefrontal regions, key components of the signal detection network.	Positive
Hippocampus (limbic (hippocampal) regions)	brain morphology and function	P200 (P200)	neurobiological system		P200 alterations were localised to limbic (hippocampal), temporal and ventral prefrontal regions, key components of the signal detection network.	Positive
Attention (attentional impairment)	cognition and behavior	P200 (P200)	neurobiological system		This P200 increase in depression could provide a potential mechanism for the attentional impairment frequently observed in depression	Positive
ventrolateral prefrontal cortex (ventral prefrontal regions)	brain morphology and function	P200 (P200)	neurobiological system		P200 alterations were localised to limbic (hippocampal), temporal and ventral prefrontal regions, key components of the signal detection network.	Positive
MDD	syndrome	P300 (P300)	neurobiological system		A subsequent reduction and delay in the P300 was also revealed for MDD indicating that the pronounced lack of discrimination in clinical depression may also lead to impaired stimulus evaluation.	Positive
Cognitive performance (impaired stimulus evaluation)	cognition and behavior	P300 (P300)	neurobiological system		A subsequent reduction and delay in the P300 was also revealed for MDD indicating that the pronounced lack of discrimination in clinical depression may also lead to impaired stimulus evaluation.	Positive
Reaction time (slower and more variable response times)	cognition and behavior	P200 (P200)	neurobiological system		The key finding was a dimensional exaggeration of the P200 (140-270 ms) to both target (signal) and non-target (noise) stimuli, most pronounced in MDD, followed by PDM, relative to CTL. This exaggeration was coupled with slower and more variable response times, suggesting that neural systems are attempting to compensate for a difficulty in discriminating signal from noise.	Positive
MDD	syndrome	P200 (P200)	neurobiological system		The key finding was a dimensional exaggeration of the P200 (140-270 ms) to both target (signal) and non-target (noise) stimuli, most pronounced in MDD, followed by PDM (participants with depressed mood), relative to CTL (healthy controls).	Positive
Executive functions (lack of discrimination)	cognition and behavior	P300 (P300)	neurobiological system		A subsequent reduction and delay in the P300 was also revealed for MDD indicating that the pronounced lack of discrimination in clinical depression may also lead to impaired stimulus evaluation.	Positive