What are the pros and cons of multidisciplinary research?
This does not fully answer your question, but it is certainly one consideration.

Multidisciplinary theses are often examined by multidisciplinary committees.
Examining such theses is difficult, especially if the committee has no experience examining multidisciplinary theses.
 A consequence is that you will often be forced to conform to the conventions of different communities. In addition, the chemistry committee member may not see the thesis as a chemistry thesis and the sociology committee member may not see the thesis as a sociology thesis, because it lies somewhere in between the two fields and cannot be a complete thesis in both fields.