Do Indexed Fields improve performance in Reporting as well as in Lists?

Hi,

I just wanted to confirm this.  Here is what it says in Help about Indexed Fields:  "These optimized fields, which are called indexed custom fields, are special fields that improve the response time during a search or when sorting a particular list."

It doesn't say anything about Reporting and Analytics.  You would think this would be a performance boost everywhere, but I would just like to confirm.

Thanks!