Investors continue to keep a close eye on the progress of companies involved in developing medicines targeting the central nervous system and, in the main, their reaction has been generally positive. The BioWorld Neurological Diseases index, a price-weighted index of public biopharmaceutical companies that are focused on developing therapies to treat neurological diseases, closed the year up over 16% and after, a dip in January, is now tracking up more than 12% by market close on Friday Feb. 21, well ahead of the general markets for the same period.