Demand for neurologists remains strong, driven by an aging population and the increase of chronic illness. Educational barriers to entry for neurologists remain high. A bachelor's degree with pre-medical coursework in biology, mathematics and chemistry is required. Following completion, a medical degree (MD) and several years of post-graduate supervised residency experience in a hospital or clinic is required. Some neurologists who intend to pursue research choose to earn joint MD-PhD degrees, which require the additional completion of a dissertation.