Although many public biopharmaceutical companies have struggled to find traction this year, those that are concentrating on developing therapies to treat neurological diseases have performed very well. As a result, by the end of April, the BioWorld Neurological Diseases index, a price-weighted index of representative companies that are developing therapies for CNS diseases, had climbed more than 17% compared to a 14% rise in the Dow Jones Industrial Average.