Functional and structural connectivity of the amygdala in obsessive-compulsive disorder.

Abstract

BackgroundThe amygdala is known to be involved in anxiety processing, but its role in the psychopathology of obsessive-compulsive disorder (OCD) is still unclear.AimsIn this MRI study we investigated potential alterations in structural and functional connectivity of the amygdala in 42 adult patients with OCD and 37 healthy subjects.MethodPsychophysiological interaction analysis was used to explore amygdala functional connectivity during a negative affective task. Probabilistic tractography was then employed to study structural connectivity and integrity of underlying white matter fiber tracts.ResultsCompared to controls, OCD patients showed a significantly increased functional connectivity of the left amygdala with mostly parieto-occipital regions during task. No structural connectivity differences could be found between the groups. In addition, only patients showed a significant association between functional and structural connectivity of these regions. Moreover, symptom severity was negatively associated with structural integrity of the underlying white matter tracts.ConclusionsPresent results emphasize the relevance of the amygdala for OCD and may reflect that neuronal alterations in structural connectivity could be associated with functional connectivity alterations in broader networks.