Acute Tryptophan Depletion Effects on the Vertex and Late Positive Potentials to Emotional Faces in Individuals with a Family History of Depression

Background: Depression, which is associated with dysfunctional serotonin ( 5-HT) activity, may be characterized by impaired emotional information processing. This study assessed the effects of acute tryptophan depletion (TRP-), which transiently lowers CNS 5-HT, on the emotion-sensitive vertex positive potential (VPP) and late positive potential (LPP) event-related potentials (ERPs) and mood in individuals with a family history of depression. The VPP and LPP are thought to index the early and later stages of motivated attentional processing, respectively. Method: Within a double-blind balanced design, ERPs were acquired in 18 individuals with a family history of depression (12 females) after TRP- and TRP+ (balanced) treatment while participants were presented with facial expressions (neutral, as well as sad, joy and surprise at 50 and 100% intensity) and responded to surprised faces. Results: TRP- increased total mood disturbance and maintained depression scores. The VPP and LPP were larger to intense versus mild expressions. Enhanced processing of emotional versus neutral faces, as in-dexed by the VPP, was primarily evident with TRP-. Speeded and enhanced processing of intensely joyful versus mildly sad faces was found with TRP- (VPP indexed). Compared with TRP+, TRP also increased the VPP to mildly joyful faces. Conclusion: Transient 5-HT decreases in individuals with a family history of depression induce subtle changes in early stages of motivated emotional processing, though not in later ones. Copyright (C) 2011 S. Karger AG, Basel