Yes. If you have small children that might be climbing on your fireplace then in might be a good idea to use an anti-topple kit.
Similarly, if you live in an earthquake zone, an anti-topple kit can be used to anchor your fireplace mantel to the wall. It’s usually not necessary, but if you’re concerned with safety, it’s not a bad idea. Anti-topple kits are inexpensive and can be purchased at most hardware stores or online. They are not included.