Background: Major Depressive Disorder (MDD) is a burdensome and highly recurrent disorder, with a heightened risk of relapse for those with residual symptoms from previous episodes of depression. Mapping key mechanisms of the disease in a sample currently in remission is essential for developing efficient treatment. The Model of Cognitive Control of Emotion suggests deficits in emotion regulation in people with MDD is an important mechanism driving the recurrence of depression. Based on this model, differences in emotion regulation abilities will manifest themselves as differences in white matter integrity between a sample of patients with a history of MMD and healthy controls (HCs). Objectives: Our primary objective was to investigate the role of white matter integrity in a sample of MDD patients currently in remission and HCs. This was addressed using three common measures of Diffusion Tensor Imaging (DTI): fractional anisotropy (FA), mean diffusion (MD) and radial diffusion (RD). We hypothesised that the MDD group would show lower mean FA and higher MD and RD values than the controls. Our secondary objectives were to examine if these differences were related to the level of depressive symptoms, and to investigate the relation between white matter integrity and emotion regulation strategies within brain areas of significant group differences in white matter integrity. Methods: The study sample consisted of 151 people with a history of MDD, currently in remission, and 72 HCs. Clinical screening was conducted through the Mini International Neuropsychiatric Interview (M.I.N.I 6) in accordance with DSM-IV diagnostic criteria for MDD. Whole-brain voxelwise statistical analyses of the FA, MD and RD data were carried out using Tract-Based Spatial Statistics (TBSS). The level of depressive symptoms was measured by the Beck Depression Inventory (BDI) and the Hamilton Rating Scale for Depression (HRSD), and the emotion regulation strategies were measured by the Cognitive Reappraisal (CR) facet on the Emotion Regulation Questionnaire (ERQ). Results: Significant group differences between MDD patients and HCs were found on all three white matter measures in several brain regions assumed to be related to emotion regulation. The affected areas involve anterior corona radiate, the cingulum, the internal capsule, uncinate fasciculus, forceps minor, splenium of corpus callosum and superior longitudinal fasciculus. There were no significant correlations between depressive symptom scores and FA, MD or RD in any areas of the brain. Nor did the differences in white matter between the two groups seem to be mediated by the participants’ emotion regulation strategies. Conclusion: Our study provides important information about the relation between white matter integrity, emotion regulation and depressive symptoms in people with a high risk of depressive relapse. It highlights the importance of thorough investigation of underlying mechanisms of MDD for developing new treatments, including mechanisms that are detectable in remission. Emotion regulation deficits do not seem to be related to these neurobiological mechanisms and can possibly be considered more of an artefact related to ongoing depression. In addition, the underlying mechanisms do not seem to worsen with the severity of depressive symptoms. This could, however, be due to our study not including enough patients with symptoms of severe depression, thus restricting the range of our sample.