The question of whether a song like 'Addiction' is copyrighted boils down to a fundamental principle: copyright law protects original musical works. If 'Addiction' is a unique composition with original lyrics and melody, it's almost certainly protected by copyright.
Copyright protection is automatic upon creation; you don't need to register a song for it to be copyrighted. However, registering with the U.S. Copyright Office provides significant legal advantages if infringement occurs.
To definitively check if a specific song titled 'Addiction' is copyrighted and by whom, you can search public databases like the U.S. Copyright Office records or PRO (Performing Rights Organization) databases such as ASCAP, BMI, and SESAC. These searches can reveal ownership and registration details.
Remember, even if the song isn't officially registered, the original creator likely holds the copyright. Understanding these aspects is key before using any musical work in your own projects.