Is this possible?
No you can't do this.
Where the passage you are studying is referenced in a document you have created (such as a notesfile) it will show up in My Content.
Any particular reason why this is causing a problem?
I do a lot of highlighting so these show up in just about any search. It's not a big problem, just wondered if there was a way to exclude this from search results.
You can exclude "My Content" totally by creating a custom Passage Guide - see http://wiki.logos.com/Customizing_the_Passage_and_Exegetical_Guides for some pointers - but I am assuming you don't want to exclude all of your content from these searches.