Article

Increased amygdala and decreased dorsolateral prefrontal BOLD responses in unipolar depression: related and independent features.

Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
Biological Psychiatry (Impact Factor: 9.47). 02/2007; 61(2):198-209. DOI: 10.1016/j.biopsych.2006.05.048
Source: PubMed

ABSTRACT Major depressive disorder is characterized by increased and sustained emotional reactivity, which has been linked to sustained amygdala activity. It is also characterized by disruptions in executive control, linked to abnormal dorsolateral prefrontal cortex (DLPFC) function. These mechanisms have been hypothesized to interact in depression. This study explored relationships between amygdala and DLPFC activity during emotional and cognitive information processing in unipolar depression.
Twenty-seven unmedicated patients with DSM-IV unipolar major depressive disorder and 25 never-depressed healthy control subjects completed tasks requiring executive control (digit sorting) and emotional information processing (personal relevance rating of words) during event-related functional magnetic resonance imaging (fMRI) assessment.
Relative to control subjects, depressed subjects displayed sustained amygdala reactivity on the emotional tasks and decreased DLPFC activity on the digit-sorting task. Decreased relationships between the time-series of amygdala and DLPFC activity were observed within tasks in depression, but different depressed individuals showed each type of bias.
Depression is associated with increased limbic activity in response to emotional information processing and decreased DLPFC activity in response to cognitive tasks though these may reflect separate mechanisms. Depressed individuals also display decreased relationships between amygdala and DLPFC activity, potentially signifying decreased functional relationships among these structures.

0 Followers
 · 
163 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The substantial health burden associated with major depressive disorder (MDD) is a product of both its high prevalence and the significant risk of relapse, recurrence, and chronicity. Establishing recurrence vulnerability factors (VFs) could improve the long-term management of MDD by identifying the need for further intervention in seemingly recovered patients. We present a model of sensitization in depression vulnerability, with an emphasis on the integration of behavioral and neural systems accounts. Evidence suggests that VFs fall into 2 categories: dysphoric attention and dysphoric elaboration. Dysphoric attention is driven by fixation on negative life events, and is characterized behaviorally by reduced executive control, and neurally by elevated activity in the brain's salience network. Dysphoric elaboration is driven by rumination that promotes overgeneral self- and contextual appraisals, and is characterized behaviorally by dysfunctional attitudes, and neurally by elevated connectivity within normally distinct prefrontal brain networks. Although few prospective VF studies exist from which to catalogue a definitive neurobehavioral account, extant data support the value of the proposed 2-factor model. Measuring the continued presence of these 2 VFs during recovery may more accurately identify remitted patients who would benefit from targeted prophylactic intervention. (PsycINFO Database Record (c) 2015 APA, all rights reserved).
    Journal of Abnormal Psychology 02/2015; 124(1):38-53. DOI:10.1037/abn0000031 · 4.86 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The ability to detect and respond to errors is critical to successful adaptation to a changing environment. The error-related negativity (ERN), an event-related potential (ERP) component, is a well-validated neural response to errors and reflects the error monitoring activity of the anterior cingulate cortex (ACC). Additionally, the ERN is implicated in several processes key to adaptive functioning. Abnormalities in error-related brain activity have been linked to multiple forms of psychopathology and individual differences. As such, the component is likely to be useful in NIMH's Research Domain Criteria (RDoC) initiative to establish biologically-meaningful dimensions of psychological dysfunction, and currently appears as a unit of measurement in three RDoC domains: Positive Valence Systems, Negative Valence Systems, and Cognitive Systems. In this review paper, we introduce the ERN and discuss evidence related to its psychometric properties, as well as important task differences. Following this, we discuss evidence linking the ERN to clinically diverse forms of psychopathology, as well as the implications of one unit of measurement appearing in multiple RDoC dimensions. And finally, we discuss important future directions, as well as research pathways by which the ERN might be leveraged to track the ways in which dysfunction of multiple neural systems interact to influence psychological well-being. Copyright © 2015. Published by Elsevier B.V.
    International journal of psychophysiology: official journal of the International Organization of Psychophysiology 03/2015; DOI:10.1016/j.ijpsycho.2015.02.029 · 2.65 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Functional magnetic resonance imaging was used during emotion recognition to identify changes in functional brain activation in 21 first-episode, treatment-naive major depressive disorder patients before and after antidepressant treatment. Following escitalopram oxalate treatment, patients exhibited decreased activation in bilateral precentral gyrus, bilateral middle frontal gyrus, left middle temporal gyrus, bilateral postcentral gyrus, left cingulate and right parahippocampal gyrus, and increased activation in right superior frontal gyrus, bilateral superior parietal lobule and left occipital gyrus during sad facial expression recognition. After antidepressant treatment, patients also exhibited decreased activation in the bilateral middle frontal gyrus, bilateral cingulate and right parahippocampal gyrus, and increased activation in the right inferior frontal gyrus, left fusiform gyrus and right precuneus during happy facial expression recognition. Our experimental findings indicate that the limbic-cortical network might be a key target region for antidepressant treatment in major depressive disorder.
    Neural Regeneration Research 05/2012; 7(15):1151-7. DOI:10.3969/j.issn.1673-5374.2012.15.005 · 0.23 Impact Factor

Full-text (2 Sources)

Download
316 Downloads
Available from
May 22, 2014

Similar Publications