The Effect of Duloxetine on Interoceptive Awareness

This study focuses on possible mechanism mediating duloxetine effects on painful physical symptoms in patients suffering from MDD. Our hypothesis is based on the assump¬tion of dual impairment of the somatosensory system in these patients. Hypalgesia to phasic experimental pain may be due to diminished spinal and brainstem transmission. Hyperalgesia may be at¬tributed to increased interoceptive perception (somatic complaints, especially those consist¬ing in pain) due to sensitisation or lack of inhibition of the interceptive perception. These ef¬fects seem to be mediated by specific brain regions (e.g. the right insula). The investigators intent to test if duloxetine effects on these somatic complaints, especially pain complaints are due to a nor¬malization of these interceptive alterations which have been reported to be associated with depressive symptoms. The investigators hypothesize that treatment with duloxetine will normalize "patho¬logical" activation patterns (as assessed by fMRI) associated with increased interoceptive perception.