Professor Andersen obtained his medical degree from Copenhagen University and specialised in neurology. In the same year he also completed his doctoral thesis on SOD1 genetics and pathology in ALS. After this, he moved for one year to MGH/Harvard Medical School for his postdoctoral research. In 1992, he established the multidisciplinary Clinical Care ALS Team at Umeå University Hospital that cares for patients from northern Sweden and also sees second-opnion patients from other parts of Sweden and abroad. His research focuses on genetics, free radicals and SOD1 protein-prion research. He also has an interest in biomarker research. He has been a senior neurologist since 2001 and was appointed as a Professor in Neurology in 2010. He has won various prizes including the Charcot Prize (2000) and the Wallenberg Clinical Scholar 2016—2020 for focused ALS Research.