A BioPsychoSocial approach in professional psychology. Why would we take this approach?

A BioPsychoSocial approach in" rel="nofollow">in professional psychology. Why would we take this approach? Instructions uploaded below Lin" rel="nofollow">ink to Text: https://www.dropbox.com/s/8scujairuum8wrv/TEXT%20%5BMelchert%5D%20Professional_Psych%202011.pdf?dl＝0