Cognitive deficits are highly prevalent in multiple sclerosis patients, even in the early phases of the disease, and have a profound impact in patient’s wellbeing and quality of life. Their genesis is still poorly understood, but a contribution of both inflammatory and neurodegeneration components is highly likely. Detection of cognitive deficits relies on time-consuming tests, which are difficult to implement in clinical practice. Furthermore, there are almost no therapeutic options available. In this encompassing project we aim to explore the determinants of cognitive deficits in patients with multiple sclerosis, contribute to develop and validate patient- and physician-friendly methods for their detection and characterization (CogEval) and test novel treatment strategies, that are tailored to each individual patient, using a pharmaco-MRI approach (MODEFIMS).