Check if site visitor is logged into CMS

I am looking for a way to check if the current page visitor is logged into the CMS. 

I want my client to be able to review new issues that are marked with a issue_status field as "setup", so they are only viewable by someone who is logged into the CMS. 

Thinking I may need to activate the membership plugin to do this, but was hoping there is a simpler method to access the global $CURRENT_USER