They say the star spent more than $75m (£59.6m) on 14 homes and needed 12 storage facilities to house his collection of Hollywood memorabilia.
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.
Their legal action, obtained by the Deadline website, also accuses the actor of spending:
Last month, Depp claimed The Management Group owed him more than $25m.
His lawsuit also alleges the company failed to file him taxes on time, costing him $5.7m (£4.5m) in penalties.
Depp's latest legal tussle comes in the wake of his divorce to Amber Heard, which was finalised in January after months of wrangling.
The 53-year-old will be seen later this year as Captain Jack Sparrow in Pirates of the Caribbean: Salazar's Revenge.
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Johnny Depp's financial troubles are caused by his lavish lifestyle, claim the former business managers he is suing for mismanaging his earnings.