It could be that it has accidentally gone hidden, you can go to Edit > Menus... and from the Menu customization dialog that opens up chose the Set as "InDesign Defaults" of not already, or you can check under Window there in the Application Menu Command list whether Effects visibility is set to show or hide.
Try resetting the preferences.
Rename Version # to old Version # from both these locations.
Hard Drive/Users/<USER>/Library/Caches/Adobe InDesign/<Version 8>
Hard Drive/Users/<USER>/Library/Preferences/Adobe InDesign/<Version 8>
Access Hidden Library:
Once those two folders are renamed, try to launch the application again and check.