They claim he spent more than $75m (£59.6m) on 14 homes and $3m (£2.4m) blasting author Hunter S Thompson's ashes out of a cannon.
The Management Group are countersuing Depp after the Pirates of the Caribbean actor sued them for $25m (£20m).
Depp, they claim, is "fully responsible for any financial turmoil" he faces.
"He has refused to live within his means, despite... repeated warnings about his financial condition," their countersuit claims.