Will users know to click the top item in navigation menu?

I've got a navigation menu on my website which has several levels of submenu.

In the example pictured below I'd like users to be able to click "Services" in the top level menu and go to a "services" page. But I'm worried they won't think it is clickable, and will assume only the bottom level actually will take you to a page.

Can anyone advise? Has there been any research done on this?