Exhibit 4.1


SECOND
AMENDMENT TO RIGHTS AGREEMENT


This Second Amendment to Rights Agreement (“Second
Amendment”) is made and entered into as of December 20, 2006 (the “Effective
Date”), between Horizon Health Corporation, a Delaware corporation formerly
named Horizon Mental Health Management, Inc. (the “Company”), and American
Stock Transfer & Trust Company (the “Rights Agent”).


RECITALS


WHEREAS, the Company and the Rights Agent entered into
that certain Rights Agreement dated as of February 6, 1997 (“Original
Agreement”) granting to holders of Common Stock of the Company the right to
purchase additional shares of Common Stock on the terms and subject to the conditions
set forth in the Original Agreement, and also entered into a First Amendment to
Rights Agreement dated as of April 22, 2005 amending the Original
Agreement (the Original Agreement, as amended by the First Amendment to Rights
Agreement, collectively the “Agreement”); and


WHEREAS, Section 27 of the Agreement provides
that the Company may amend the Agreement as it deems necessary or desirable
without the approval of any holders of Rights under certain circumstances;


WHEREAS, the Board of Directors of the Company (the “Board
of Directors”) intends to approve the execution, delivery and performance by
the Company of, and the consummation of the merger and all other transactions
contemplated by, that certain Agreement and Plan of Merger by and among the
Company, Psychiatric Solutions, Inc., a Delaware corporation (“Parent”), and Panther
Acquisition Sub, Inc., a Delaware corporation and subsidiary of Parent (“Merger
Sub”), in substantially the form presented to and reviewed by the Board of
Directors; and


WHEREAS, in contemplation of consummation of the
merger and the other transactions contemplated by the Merger Agreement, the
Board of Directors deems it necessary and desirable and in the best interests
of the Company and its stockholders to adopt this Second Amendment;


NOW, THEREFORE, in consideration of the foregoing and
the mutual covenants and agreements contained in this Second Amendment, the
parties, intending to be legally bound, hereby agree as follows:


ARTICLE I.

DEFINED TERMS


Section 1.1            Defined
Terms.  Unless otherwise
stated herein, (a) each capitalized term used in this Second Amendment shall
have the same meaning as provided for such term in the Agreement, and (b) all
underlined section references in this Second Amendment are references to the
corresponding section of the Agreement.



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ARTICLE II.

AMENDMENTS AND EFFECTIVENESS 

OF AMENDMENTS


Section 2.1            Amendments.  Subject to the provisions of
Section 2.2 hereof, the Agreement is hereby amended as follows:


(a)          The Agreement shall
be amended by adding the following new Section 35:


“Section 35.  Transactional Exemption.


(a)          Notwithstanding anything to the
contrary in this Agreement, neither the execution, delivery nor performance by
the respective parties thereto of that certain Agreement and Plan of Merger
dated as of December 20, 2006 (the “Merger Agreement”), by and among the
Company, Psychiatric Solutions, Inc., a Delaware corporation (“Parent”), and Panther
Acquisition Sub, a Delaware corporation and subsidiary of Parent (“Merger Sub”),
nor the consummation of the Merger (as that term is defined in the Merger
Agreement) or any other transactions contemplated by the Merger Agreement,
shall cause any Person to become an “Acquiring Person” (as that term is defined
in Section 1(a) hereof), or give rise to any event that, through passage
of time or otherwise, would result in the occurrence of a “Stock Acquisition
Date” or an “Exercisability Date” (as those terms are defined in
Sections 1(l) and 3(a), respectively, of this Agreement).”


(b)         Section 7(a) shall be amended and
restated to read as follows:


“Section 7.  Exercise
of Rights; Exercise Price; Expiration Date of Rights.


(a)          At any time after the Exercisability
Date and prior to the earlier of (i) the Close of Business on March 4,
2007 (the “Final Expiration Date”), (ii) the time at which the
Rights are redeemed as provided in Section 23 (the “Redemption
Date”), (iii) the time at which the Rights are exchanged as provided
in Section 24, and (iv) the Effective Time (as defined in the
Merger Agreement) (the earlier of (i), (ii), (iii) and (iv) being the “Expiration
Date”), the registered holder of any Rights Certificate may, subject to the
provisions of Section 7(e), exercise the Rights evidenced thereby
in whole or in part upon surrender of the Rights Certificate, with the form of
election to purchase duly executed, to the Rights Agent at the office of the
Rights Agent designated for such purpose, together with payment of the
aggregate Exercise Price for the number of shares of Common Stock (or,
following a Triggering Event, other securities, cash or other assets, as the
case may be) for which such surrendered Rights are then exercisable.”


A corresponding change to the definition of the term “Expiration
Date” shall be deemed to be made in the last sentence of paragraph 2 of
the Summary of Rights Agreement attached as Exhibit B to the
Agreement.


(c)           Notwithstanding anything to the
contrary in this Agreement, the provisions of Section 13 of this Agreement
shall be deemed not to apply to the Merger or any other transactions
contemplated by the Merger Agreement.



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Section 2.2            Condition
to Effectiveness.  This Second
Amendment shall become effective immediately upon the execution and delivery of
the Merger Agreement by each of the parties thereto; provided, however, that if
the Merger Agreement is terminated for any reason, this Second Amendment shall
no longer be applicable or of any further force and effect.


Section 2.3            Reference
to and Effect on Rights Agreement.  Upon the effectiveness of this Second Amendment
pursuant to the provisions of Section 2.2 hereof, each reference in the
Rights Agreement to “this Agreement,” “hereunder,” “hereof,” “herein” or any
other expression of like import referring to the Rights Agreement shall mean
and be a reference to the Agreement as amended by this Second Amendment.


ARTICLE III.

MISCELLANEOUS


Section 3.1            Certification.
 The undersigned officer of
the Company certifies to the Rights Agent on behalf of the Company that this Second
Amendment is in compliance with the terms of Section 27 of the
Agreement.


Section 3.2            Remainder
of Agreement Not Affected. 
While in effect pursuant to the terms of Section 2.2, in the event
of any conflict between the terms of this Second Amendment and the terms of the
Agreement, the terms of this Second Amendment shall control, and the Agreement,
as amended hereby, shall remain in full force and effect.


Section 3.3            Governing
Law.  This Second
Amendment shall be governed by and construed in accordance with the internal
and substantive laws of the State of Delaware, without regard to any conflicts
of law concepts thereof that would result in the application of the substantive
law of any other jurisdiction.


Section 3.4            Facsimile
Signatures; Counterparts.  Facsimile
transmission of any signed original document and/or retransmission of any
signed or signed facsimile transmission shall be the same as delivery of an original.
 At the request of either party to this Second
Amendment, the parties will confirm facsimile transmission by signing and
delivering a duplicate original document.  This Second Amendment may be executed in
multiple counterparts each of which shall be deemed an original and all of
which together shall be considered one and the same agreement.


[Remainder
of page intentionally left blank. 
Signature page follows.]



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IN WITNESS WHEREOF, each of the parties has duly
executed this Second Amendment as of the date first set forth above.


	
  

  	
   

  	
  HORIZON HEALTH CORPORATION

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
   

  	
  /s/ James Ken Newman

  	
   

  	 

	
   

  	
   

  	
  Name:

  	
   

  	
  James Ken Newman

  
	
   

  	
   

  	
  Title:

  	
   

  	
  Chief Executive Officer

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  AMERICAN STOCK TRANSFER & TRUST COMPANY

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  /s/ Herbert J.
  Lemmer

  	
   

  	 

	
   

  	
   

  	
  Name:

  	
  Herbert J.
  Lemmer

  	
   

  	 

	
   

  	
   

  	
  Title:

  	
  Vice President

  	
   

  
													



 



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