Include the Add Constituent Button either at the top in the navigation bar, or as a drop down menu option. This will not only make the option to add a constituent easily accessible, but allow for the user's workflow to move forward, instead of stopping - to go to the home page, and then back to the task, or going to backwards a step to the home page when you were working on a List, or other item.
Just a comment that you do have the option to duplicate the tab and leave your task just where you are while going to [Home] and adding the new Constituent from the duplicate tab.