Depressive symptoms and autobiographical memory: A pilot electroencephalography (EEG) study.
INTRODUCTION
Functional magnetic resonance imaging studies have shown changes in the activity of medial prefrontal, medial temporal, and occipital regions in major depressive disorder patients during recall of autobiographical memories. Electrophysiological underpinning of these changes is not known. It is also not clear whether they are a part of the clinical picture or appear at preclinical stages in individuals predisposed to depression.


METHOD
In this study, the effect of depressive symptoms, as measured by the Beck Depression Inventory (BDI-II), on oscillatory dynamics accompanying retrieval of emotionally positive and negative autobiographical memories was investigated in a nonclinical sample using electroencephalographic event-related spectral power and connectivity measures.


RESULTS
Psychometric results showed that BDI scores correlated positively with the strength of negative emotion, vividness of negative memories, and their importance for participant's life. In high BDI scorers, low-frequency synchronization, which is frequently used as a marker of emotional arousal, prevailed in negative episodes, whereas in low BDI scorers it prevailed in positive episodes. sLORETA localized sources of this synchronization in the medial prefrontal cortex. In negative episodes, depressive symptoms were associated with a diminished event-related connectivity in the alpha band in posterior regions and increased connectivity in beta and gamma bands in frontal regions.


CONCLUSIONS
Overall, these results show that even at preclinical stages, depressive symptoms are associated with changes in electrophysiological processes accompanying retrieval of autobiographical memories.
['Knyazev|Gennady G|GG|', 'Savostyanov|Alexander N|AN|', 'Bocharov|Andrey V|AV|', 'Kuznetsova|Valeriya B|VB|']
D000293:Adolescent D000328:Adult D001921:Brain D003863:Depression D004569:Electroencephalography D004644:Emotions D005260:Female D006801:Humans D008297:Male D061212:Memory, Episodic D011939:Mental Recall D011569:Psychiatric Status Rating Scales D055815:Young Adult
Depression Autobiographical memory Electroencephalography sLORETA Functional connectivity