09:19 AM EDT, 09/24/2025 (MT Newswires) -- Acadia Healthcare ( ACHC ) activist investor Engine Capital said Wednesday that it has secured a 3% stake in the mental health group and called on the company to "refresh" its board by adding new directors with expertise in behavioral health and capital allocation.

Engine said in a letter to Acadia's board that the company's performance lately has been driven by several factors, including "ineffective execution, a bloated corporate structure, poor decision-making," and "a culture that has emphasized 'growth at any cost'."

The hedge fund said Acadia needs to "fundamentally" alter its strategy by immediately halting growth capital investments, selling assets to raise cash, and repurchasing its "undervalued" shares, among others.

Acadia shares were up more than 5% in recent Wednesday premarket activity.

Acadia could not be immediately contacted for a comment.