I originally intended to take the current version of the MCAT. So, I bought all the prep books for the current MCAT. However, I realized that I need more time to study which means I would have to take the 2015 MCAT. So, are my old MCAT books useless now? Should I order books that are specifically designed for the 2015 MCAT? Or should I use the current MCAT books and just order books that pertain to Biochemistry, Psychology and Sociology? Is the 2015 MCAT pretty much the same as the current MCAT with just Biochemistry, Psychology and Sociology added?