Exhibit 10.3

FIFTH AMENDMENT

THIS FIFTH AMENDMENT (this “Amendment”), dated as of June 15, 2012, to the Credit Agreement referenced below is by and among Acadia Healthcare Company, Inc. (f/k/a Acadia Healthcare Company, LLC), a Delaware corporation (the “Borrower”), the Guarantors identified on the signature pages hereto, the Lenders identified on the signature pages hereto and Bank of America, N.A., in its capacity as Administrative Agent (in such capacity, the “Administrative Agent”).

W I T N E S S E T H

WHEREAS, revolving credit and term loan facilities have been extended to the Borrower pursuant to the Credit Agreement (as amended, modified, supplemented, increased and extended from time to time, the “Credit Agreement”) dated as of April 1, 2011, by and among the Borrower, the Guarantors identified therein, the Lenders identified therein and the Administrative Agent; and

WHEREAS, the Borrower has requested certain modifications to the Credit Agreement and the Required Lenders have agreed to such modifications to the Credit Agreement on the terms and conditions set forth herein.

NOW, THEREFORE, IN CONSIDERATION of the premises and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto agree as follows:

1. Defined Terms. Capitalized terms used herein but not otherwise defined herein shall have the meanings provided to such terms in the Credit Agreement.

2. Amendments. The Credit Agreement is amended as follows:

2.1 In clause (b) of the definition of Consolidated EBITDA in Section 1.01 of the Credit Agreement the “and” immediately before clause (xxvi) is deleted and replaced with “;” and new clauses (xxvii) and (xxviii) are added after clause (xxvi) to read “(xxvii) any fees, expenses or charges related to any repayment of Permanent Senior Unsecured Indebtedness with the proceeds of the Equity Issuance made by the Borrower on May 21, 2012 in an aggregate amount not to exceed $6,900,000 and (xxviii) any non-cash write-off of deferred financing costs and any other non-cash loss related, in each case, to the repayment of Permanent Senior Unsecured Indebtedness (including refinancings, amendments, waivers or other modifications) permitted hereunder;”

2.2 In clause (c) of the definition of Consolidated EBITDA in Section 1.01 of the Credit Agreement the “and” immediately before clause (ii) is deleted and replaced with “;” and a new clause (iii) is added after clause (ii) to read “and (iii) any non-cash gains related to the repayment of Permanent Senior Unsecured Indebtedness (including refinancings, amendments, waivers or other modifications) permitted hereunder.”

2.3 Section 2.05(b)(vi) of the Credit Agreement is amended in its entirety to read as follows:

(vi) Equity Issuances. Immediately upon the expiration of the 180 day period after the receipt by the Borrower or any Subsidiary of the Net Cash Proceeds of any Equity Issuance (other than an Excluded Equity Issuance described in clauses (a), (b) or (e) of such definition), the Borrower shall prepay the Loans and/or Cash Collateralize the L/C

Obligations in an aggregate amount equal to 50% of the difference between such Net Cash Proceeds and amounts used or expended by the Borrower or any Subsidiary as permitted by clauses (c) and (d) of the definition of Excluded Equity Issuance.

2.4 Section 7.02(a) of the Credit Agreement is deleted in its entirety and amended to read “[Reserved]”.

2.5 Section 8.15 of the Credit Agreement is amended in its entirety to read as follows:

8.15 Capital Expenditures.

Permit Consolidated Capital Expenditures (a) for the fiscal year ending December 31, 2011, to exceed an amount equal to four percent (4.0%) of total revenues of the Borrower and its Subsidiaries on a consolidated basis for the immediately preceding fiscal year of the Borrower and (b) for any fiscal year thereafter, commencing with the fiscal year ending December 31, 2012, to exceed an amount equal to ten percent (10.0%) of total revenues of the Borrower and its Subsidiaries on a consolidated basis for the immediately preceding fiscal year of the Borrower.

2.6 In Section 8.17(b) of the Credit Agreement clause (ii) is amended to read as follows:

(ii) the purchase, payment, prepayment or redemption of Permanent Senior Unsecured Indebtedness with up to 50% of the Net Cash Proceeds of any Equity Issuance so long as such Net Cash Proceeds are used to make such purchase, payment, prepayment or redemption within 120 days of the receipt of such Net Cash Proceeds by the Borrower or any Subsidiary.

3. Conditions Precedent. This Amendment shall become effective as of the date hereof upon receipt by the Administrative Agent of counterparts of this Amendment executed by the Borrower, the Guarantors, the Required Lenders and the Administrative Agent.

4. Amendment is a “Loan Document”. This Amendment is a Loan Document and all references to a “Loan Document” in the Credit Agreement and the other Loan Documents (including, without limitation, all such references in the representations and warranties in the Credit Agreement and the other Loan Documents) shall be deemed to include this Amendment.

5. Representations and Warranties; No Default. Each Loan Party represents and warrants to the Administrative Agent and each Lender that after giving effect to this Amendment (a) the representations and warranties of each Loan Party contained in the Credit Agreement or any other Loan Document, or which are contained in any document furnished at any time under or in connection with the Credit Agreement or any other Loan Document are true and correct in all material respects on and as of the date hereof, except to the extent that such representations and warranties specifically refer to an earlier date, in which case such representations and warranties are true and correct in all material respects as of such earlier date, and (b) no Default exists.

6. Reaffirmation of Obligations. Each Loan Party (a) acknowledges and consents to all of the terms and conditions of this Amendment, (b) affirms all of its obligations under the Loan Documents and (c) agrees that this Amendment does not operate to reduce or discharge such Loan Party’s obligations under the Loan Documents.

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7. Reaffirmation of Security Interests. Each Loan Party (a) affirms that each of the Liens granted in or pursuant to the Loan Documents are valid and subsisting and (b) agrees that this Amendment does not in any manner impair or otherwise adversely effect any of the Liens granted in or pursuant to the Loan Documents.

8. No Other Changes. Except as modified hereby, all of the terms and provisions of the Loan Documents shall remain in full force and effect.

9. Counterparts; Delivery. This Amendment may be executed in counterparts (and by different parties hereto in different counterparts), each of which shall constitute an original, but all of which when taken together shall constitute a single contract. Delivery of an executed counterpart of this Amendment by facsimile or other electronic imaging means shall be effective as an original.

10. Governing Law. This Amendment shall be deemed to be a contract made under, and for all purposes shall be construed in accordance with, the laws of the State of New York.

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IN WITNESS WHEREOF, the parties hereto have caused this Fifth Amendment to be duly executed as of the date first above written.

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