<PAGE>

                                                               Exhibit 4.13

           SECOND AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT

      THIS SECOND AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT
("Agreement") is made this 17th day of June, 1996, among AMERICAN PSYCH SYSTEMS,
INC., a Delaware corporation ("Company"), and APPLEWOOD ASSOCIATES, L.P., a New
York limited partnership ("Applewood"), SENECA VENTURES, a New York limited
partnership ("Seneca"), WOODLAND PARTNERS, a New York general partnership
("Woodland Partners"), WOODLAND VENTURE FUND, a New York limited partnership
("Woodland Venture"), NAZEM & COMPANY IV, L.P., a Delaware limited partnership
("Nazem"), and OXFORD HEALTH PLANS, INC., a Delaware corporation ("Oxford").
(Applewood, Seneca, Woodland Partners and Woodland Venture are herein referred
to as the "Applewood Investors".) (The Applewood Investors, Nazem and Oxford are
herein after referred to as the "Investors".)

      WHEREAS, the Applewood Investors purchased an aggregate of 2,049,180
shares of the Company's Series I Convertible Preferred Stock ("Series I
Preferred Stock") pursuant to the terms of a Series I Convertible Preferred
Stock Purchase Agreement ("Purchase Agreement");

      WHEREAS, as further inducement for the Applewood Investors to purchase
such shares of Convertible Preferred Stock, the Company agreed to provide
certain registration rights under the Securities Act of 1933, as amended, and
the rules and regulations thereunder (collectively, the "Act"), with respect to
the Common Stock issuable upon conversion of the Series I Preferred Stock, in
accordance with the terms and conditions set forth in a Registration Rights
Agreement dated April 3, 1995 (the "First Registration Rights Agreement");

      WHEREAS, Nazem has purchased (i) 1,024,590 shares of Series I Preferred
Stock from the Company pursuant a Second Series I Convertible Preferred Stock
Purchase Agreement dated July 18, 1995 (the "Second Purchase Agreement") and
(ii) an additional 1,024,590 shares of Series I Preferred Stock pursuant to
Third Series I Convertible Preferred Stock Purchase Agreement dated December 28,
1995 (the "Third Purchase Agreement"). As a condition for its purchase of the
Series I Preferred Stock, Nazem required that certain amendments be made to the
First Registration Rights Agreement, and such amendments be reflected in that
certain Amended and Restated Registrations Agreement, dated July 18, 1995 (the
"Second Registration Rights Agreement"), and that certain Amendment to
Registration Rights Agreement, dated December 28, 1995 (the "Third Registration
Rights Agreement") (the First Registration Rights Agreement, the Second
Registration Rights Agreement and the Third Registration Rights Agreement are
collectively referred to herein as the "Registration Rights Agreement");

<PAGE>


      WHEREAS, the Investors have purchased the Company's 10% Senior Convertible
Notes (the "Notes") in the aggregate principal amount of $2,750,000, which Notes
are convertible into shares of Series II Convertible Preferred Stock ("Series II
Preferred"), pursuant to the terms of a Note Purchase Agreement dated June 17,
1996(the "Note Purchase Agreement");

      WHEREAS, in consideration of the purchase of the Notes by the Investors,
the Company issued warrants (the "Warrants") exercisable in the aggregate for
1,127,049 shares of Series I Preferred (Series I Preferred and Series II
Preferred and collectively referred to as "Preferred Stock");

      WHEREAS, as a further inducement for the Investors to purchase the Notes,
the Company and the Investors entered into a Second Amended and Restated
Registration Rights Agreement dated June 17, 1996 which included the Common
Stock issuable upon conversion of the Preferred Stock and issuable upon exercise
of the Warrants which were being acquired pursuant to the Note Purchase
Agreement.


      The Company and each Investor covenant and agree as follows:

      I.    REGISTRATION RIGHTS.

            1.1   CERTAIN DEFINITIONS.

                  As used in this Agreement, the following terms shall have the
following respective meanings:

                  (a) "Commission" shall mean the Securities and Exchange
Commission or any other federal agency at the time administering the Act.

                  (b) "Holder" shall mean, individually, any holder of
outstanding Registrable Securities (or Warrants, Oxford Warrant or Preferred
Stock) and collectively, the holders of outstanding Registrable Securities, but
only if such holder or holders is an Investor or an assignee or transferee of
registration rights as permitted by Section 3 hereof.

                  (c) The terms "Register", "Registered" and "Registration"
refer to a registration effected by preparing and filing a registration
statement in compliance with the Act ("Registration Statement"), and the
declaration or ordering by the Commission of the effectiveness of such
Registration Statement.

                  (d) "Registrable Securities" shall mean the shares of Common
Stock issued and issuable to a Holder (i) upon


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conversion of the Preferred Stock, (ii) upon conversion of the Notes, and (iii)
upon exercise of the Warrants. As to any particular Registrable Securities, once
issued such Securities shall cease to be Registrable Securities when (w) a
registration statement with respect to the sale of such Securities shall have
become effective under the Act and such Securities shall have been disposed of
in accordance with such registration statement, (x) they shall have been sold
pursuant to Rule 144 (or any successor provision) under the Act, (y) following
the Company's initial public offering of its Common Stock, they shall have been
otherwise transferred, new certificates for them not bearing a legend
restricting further transfer shall have been delivered by the Company and
subsequent disposition of them shall not require registration or qualification
of them under the Act or any state securities or blue sky law then in force, or
(z) they shall have ceased to be outstanding.

                  (e) "Registration Expenses" shall mean all expenses incurred
by the Company in complying with Section 1 hereof, including, without
limitation, all federal and state registration, qualification and filing fees,
printing expenses, fees and disbursements of counsel and accountants for the
Company, blue sky fees and expenses, and the expense of any special audits
incident to or required by any such Registration.

                  (f) "Selling Expenses" shall mean all underwriting discounts
and selling commissions applicable to the sale of Registrable Securities by a
Holder pursuant to this Agreement.

            1.2 DEMAND REGISTRATION. If the Company shall receive a written
request from any Holder or Holders to register all or a part of such Holder's or
Holders' Registrable Securities (but not less than twenty percent (20%) of the
aggregate Registrable Securities), the Company shall, as promptly as
practicable, but in no event later than ninety (90) days after the date on which
the request for registration was given to the Company, prepare and file with the
Commission a Registration Statement sufficient to permit the public offering and
sale of such Registrable Securities, and will use its best efforts through its
officers, directors, auditors and counsel to cause such Registration Statement
to become effective as promptly as practicable and to maintain the effectiveness
thereof for at least nine (9) months; provided, however, that the Company shall
not be obligated to file such a Registration Statement covering the Registrable
Securities until six (6) months following the consummation of its initial public
offering. Other parties, including the Company, shall be permitted to offer
securities under any demand registration under this Agreement without the
consent of the holders of the Registrable Securities making such demand;
provided however that (i) any reduction in the amount of


                                     - 3 -
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securities to be included in such offering shall come from the securities
intended to be offered by parties other than the holders of the Registrable
Securities, and (ii) if there is an underwriter with respect to such offering
(which underwriter shall be a nationally recognized underwriter and shall be
chosen by the Holders of a majority of the Registrable Securities to be included
in the Registration and such underwriter shall be acceptable to the Company,
such acceptance to not be unreasonably withheld), the Company shall not include
in such demand registration, any securities held by persons other than holders
of the Registrable Securities to the extent that the underwriter determines such
securities will interfere with the successful marketing of the offering by the
Investor. The demands for Registration may be made at any time after the date
hereof. The Company shall be obligated to file two demand Registration
Statements requested by the Holders (pursuant to this Section 1.2) for which all
Registration Expenses incurred in connection with such Registration shall be
borne by the Company. A Registration Statement will not count as the one of the
two required demand Registration Statements until it has become effective.

            1.3 "PIGGY-BACK" REGISTRATION RIGHTS. If (but without any obligation
to do so) the Company proposes to Register (including for this purpose a
Registration effected by the Company for its own account and/or for stockholders
other than the Holders) any of its stock or other securities under the Act in
connection with the Registration of any Securities of the Company (other than
pursuant to Form S-8), the Company shall, at each such time, promptly give the
Holders written notice of such Registration. Upon the written request of a
Holder given within fifteen (15) days after mailing of such notice by the
Company, the Company shall, subject to the following provisions, cause to be
included in such Registration all of the Registrable Securities that the Holder
has requested to be included. The Holder's right and the Company's obligation to
have the Registrable Securities Registered under Section 1.2 and this Section
1.3 hereunder shall continue for a period of three years from the consummation
of its initial public offering.

      The Company shall be required under this Section 1.3 to include any of the
Holder's securities in an underwritten offering of the Company's securities only
in such quantity as will not, in the written opinion of the managing
underwriter(s), interfere with the successful marketing of the offering by the
Company; provided, however, that, on a percentage basis, any reduction of the
amount of securities to be included in such offering by the Holders of
Registrable Securities shall not be greater than the reductions imposed on the
other persons or entities (but not the Company) whose securities are intended to
be offered in such offering.


                                     - 4 -
<PAGE>

      Notwithstanding the foregoing, the Company shall have no obligations to
include the Investor's Registrable Securities on any registration statement if
it is prohibited from doing so pursuant to the terms of a written agreement
entered into prior to the date hereof.

            1.4 BLUE SKY. In the event of any Registration pursuant to this
Agreement, the Company will exercise its best efforts to Register and qualify
the Registrable Securities covered by the Registration Statement under such
other securities or Blue Sky laws of such jurisdictions as shall be reasonably
requested by the Holders for the distribution of such securities; provided,
however, that the Company shall not be required to qualify to do business, or to
subject itself to taxation in any state or jurisdiction in which it is not now
qualified. The Company will furnish to the Holders written advice of its counsel
with respect to registration or exemption of such Registrable Securities in such
jurisdictions.

            1.5 EXPENSES OF REGISTRATION. All Registration Expenses incurred in
connection with a Registration pursuant to this Agreement shall be borne by the
Company. All Selling Expenses shall be borne by the Holders.

            1.6   REGISTRATION PROCEDURES.

                  1.6.1 ADVICE BY COMPANY. The Company will keep the Holders
advised as to the initiation and completion of such Registration. At its expense
the Company will (i) use its best efforts to keep such Registration effective
until nine months after the effective date of the Registration Statement in the
case of a Registration on other than a Form S-3 and, in the case of any other
Registration, on the earlier of (a) the date on which the Holder has completed
the distribution described in the Registration Statement or (b) the date such
securities are no longer Registrable Securities; and (ii) furnish such number of
prospectuses (including preliminary prospectuses) and other documents as the
Holders from time to time may reasonably request.


                  1.6.2 AMENDMENTS. The Company will promptly prepare and file
with the Commission such amendments and prospectus supplements, including
post-effective amendments, to the Registration Statement as the Company
determines may be necessary or appropriate, and use its best efforts to have
such post-effective amendments declared effective as promptly as practicable;
cause the related prospectus to be supplemented by any prospectus supplement,
and as so supplemented, to be filed with the Commission; and notify the Holders
of any securities


                                     - 5 -
<PAGE>

included in such Registration Statement and the underwriter thereof, if any,
promptly when a prospectus, any prospectus supplement or post-effective
amendment must be filed or has been filed and, with respect to any
post-effective amendment, when the same has become effective.

                  1.6.3 UNDERWRITTEN OFFERINGS. In connection with an
underwritten offering in which the Registrable Securities are included, at the
request of the relevant Holders, on the date or dates that such items are
customarily provided, the Company will (a) furnish (i) an opinion, dated as of
the relevant date, of the independent counsel representing the Company for the
purposes of such Registration, addressed to the underwriter, in a customary form
and covering matters of the type customarily covered in such legal opinions; and
(ii) a comfort letter dated as of the relevant date, from the independent
certified public accountants of the Company addressed to the underwriter in a
customary form and covering matters of the type customarily covered by such
comfort letters; such opinion of counsel shall additionally cover such other
legal matters with respect to the Registration in respect of which such opinion
is being given as such underwriter may reasonably request and such letter from
the independent certified public accountants shall additionally cover such other
financial matters (including information as to the period ending not more than
five business days prior to the date of such letter) with respect to the
Registration in respect of which such letter is being given as such underwriter
may reasonably request; and (b) with such Holders, enter into customary
agreements (including an underwriting agreement in customary form) and take such
other actions as are reasonably required in order to expedite or facilitate the
disposition of such Registrable Securities.

            1.7 INFORMATION FURNISHED BY HOLDERS. It shall be a condition
precedent to the Company's obligations under this Agreement that the Holders
furnish to the Company in writing such information regarding the Holders and the
distribution proposed by the Holders as the Company may reasonably request.

            1.8   INDEMNIFICATION.

                  1.8.1 COMPANY'S INDEMNIFICATION OF THE HOLDERS. The Company
will indemnify the Holders, each of their respective officers, directors and
partners, and each person controlling the Investor within the meaning of Section
15 of the Act or Section 20(a) of the Securities Exchange Act of 1934, as
amended (the "Exchange Act"), with respect to which Registration, qualification
or compliance of Registrable Securities has been effected pursuant to this
Agreement, and each underwriter, if any, and each of its officers, directors,
constituent partners, and each person who controls any underwriter against all
claims,


                                     - 6 -
<PAGE>

losses, damages or liabilities (or actions in respect thereof) to the extent
such claim, losses, damages or liabilities arise out of or are based upon any
untrue statement (or alleged untrue statement) of a material fact contained in
any prospectus or any related Registration Statement incident to any such
Registration, qualification or compliance, or any omission (or alleged omission)
to state therein a material fact required to be stated therein or necessary to
make the statements therein not misleading, or any violation by the Company of
any rule or regulation promulgated under the Act applicable to the Company and
relating to action or inaction required of the Company in connection with any
such Registration; and the Company will reimburse the Holders, each such
underwriter and each person who controls any such Holder or underwriter, for any
legal and any other expenses reasonably incurred in connection with
investigating or defending any such claim, loss, damage, liability or action;
provided, however, that the indemnity contained in this Section 1.8.1 shall not
apply to amounts paid in settlement of any such claim, loss, damage, liability
or action if settlement is effected without the consent of the Company (which
consent shall not unreasonably be withheld or delayed); and provided, further,
that the Company will not be liable in any such case to the extent that any such
claim, loss, damage, liability or expense arises out of or is based upon any
untrue statement or omission based upon written information furnished to the
Company by the Holder and stated to be specifically for use in Registration
Statement used in connection with the offering of securities of the Company.
Notwithstanding the above, the foregoing indemnity agreement is subject to the
condition that, in so far as it relates to any such untrue statement, alleged
untrue statement, omission or alleged omission made in a preliminary prospectus,
such indemnity agreement shall not inure to the benefit of any underwriter, or
the Holders (if there is no underwriter), if a copy of the final prospectus was
not furnished to the person asserting the loss, liability, claim or damage at or
prior to the time such action is required by the Act if the final prospectus
corrected the untrue statement or omission or alleged untrue statement or
omission.

                  1.8.2 HOLDER'S INDEMNIFICATION OF COMPANY. Each Holder will,
if Registrable Securities held by the Holder are included in the securities as
to which a Registration is being effected pursuant to this Agreement, indemnify
the Company, each of its directors and officers, each underwriter, if any, of
the Company's securities covered by such a Registration Statement, each person
who controls the Company or such underwriter within the meaning of Section 15 of
the Act or Section 20(a) of the Exchange Act, against all claims, losses,
damages and liabilities (or actions in respect hereof) arising out of or based
upon any untrue statement (or alleged untrue statement) of a material fact
contained in any such Registration


                                     - 7 -
<PAGE>

Statement or related prospectus, or any omission (or alleged omission) to state
therein a material fact required to be stated therein or necessary to make the
statements therein not misleading; and will reimburse the Company, such
directors, officers, partners, persons, underwriters or control persons for any
legal and any other expenses reasonably incurred in connection with
investigating or defending any such claim, loss, damage, liability or action, in
each case to the extent, but only to the extent, that such untrue statement (or
alleged untrue statement) or omission (or alleged omission) is made in such
Registration Statement or prospectus in reliance upon and in conformity with
written information furnished to the Company by the Holder and stated to be
specifically for use in the Registration Statement used in connection with the
offering of securities of the Company; provided, however, that the Holder's
liability under this Section 1.8.2 shall not exceed such Holder's proceeds from
the offering of Registrable Securities made in connection with such
Registration.

            1.8.3 INDEMNIFICATION PROCEDURE. Promptly after receipt by an
indemnified party under this Section 1.8 of notice of the commencement of any
action, such indemnified party will, if a claim in respect thereof is to be made
against an indemnifying party under this Section 1.8, notify the indemnifying
party in writing of the commencement thereof and generally summarize such
action. The indemnifying party shall have the right to participate in and to
assume the defense of such claim and shall be entitled to select counsel for the
defense of such claim with the approval of any parties entitled to
indemnification, which approval shall not be unreasonably withheld.
Notwithstanding the foregoing, the parties entitled to indemnification shall
have the right to employ separate counsel (reasonably satisfactory to the
indemnifying party) to participate in the defense thereof, but (assuming the
indemnifying party has assumed the defense of the relevant action as aforesaid)
the fees and expenses of such counsel shall be the expense of such indemnified
parties unless the named parties to such action or proceedings include both the
indemnifying party and the indemnified parties and the indemnifying party or
such indemnified parties shall have been advised by counsel that there are one
or more legal defenses available to it which are different from or additional to
those available to the indemnifying party (in which case, if the indemnified
party notifies the indemnifying party in writing that it elects to employ
separate counsel at the reasonable expense of the indemnifying party, the
indemnifying party shall not have the right to assume the defense of such action
or proceeding on behalf of the indemnified party, as the case may be, it being
understood, however, that the indemnifying party shall not, in connection with
any such action or proceeding or separate or substantially similar or related
action or proceeding in the same


                                     - 8 -
<PAGE>

jurisdiction arising out of the same general allegations or circumstances, be
liable for the reasonable fees and expenses of more than one separate counsel at
any time for the indemnifying party and all indemnified parties, which counsel
shall be designated in writing by the Holder. If the indemnifying party
withholds consent to a settlement or proposed settlement by the indemnified
party, it shall acknowledge to the indemnified party its indemnification
obligations hereunder.

                  1.8.4 CONTRIBUTION. If the indemnification provided for in
this Section 1.8 from an indemnifying party is unavailable to an indemnified
party hereunder in respect to any losses, claims, damages, liabilities or
expenses referred to herein, then the indemnifying party, in lieu of
indemnifying such indemnified party, shall contribute to the amount paid or
payable by such indemnified party as a result of such losses, claims, damages,
liabilities or expenses in such proportion as is appropriate to reflect the
relative fault of the indemnifying party and indemnified party in connection
with the statements or omissions which result in such losses, claims, damages,
liabilities or expenses, as well as any other relevant equitable considerations.
The relative fault of such indemnifying party and indemnified party shall be
determined by reference to, among other things, whether the untrue or alleged
untrue statement of a material fact or the omission or alleged omission to state
a material fact relates to information supplied by such indemnifying party or
indemnified party and the parties' relative intent, knowledge, access to
information supplied by such indemnifying party or indemnified party and
opportunity to correct or prevent such statement or omission. The amount paid or
payable by a party as a result of the losses, claims, damages, liabilities and
expenses referred to above shall be deemed to include any legal or other fees or
expenses reasonably incurred by such party in connection with investigating or
defending any action, suit, proceeding or claim. In no event shall the amount of
any such contribution payable by a Holder exceed the amount payable by the
Holder under Section 1.8.2 hereunder.


      2.    COVENANTS OF THE COMPANY.  In connection with the Registration of
the Registrable Securities pursuant to this Agreement, the Company agrees to:

            (a) Notify the Holders, at any time when a prospectus relating to
Registrable Securities covered by the Registration Statement is required to be
delivered under the Act, of the happening of any event as a result of which the
prospectus included in the Registration Statement, as then in effect, includes
an untrue statement of a material fact or omits to state a material fact
required to be stated therein or necessary to make the statements therein not
misleading in light of the


                                     - 9 -
<PAGE>

circumstances then existing. The Company shall use its best efforts to promptly
amend or supplement the Registration Statement to correct any such untrue
statement or omission.

            (b) Notify the Holders (or in the event of an underwritten offering,
the managing underwriter(s)) of the issuance by the Commission of any stop order
suspending the effectiveness of the Registration Statement or the initiation of
any proceedings for that purpose. The Company will make every reasonable effort
to prevent the issuance of any stop order and, if any stop order is issued, to
obtain the lifting thereof at the earliest possible time.

            (c) Permit a single firm of counsel, designated by the Holders who
hold Registrable Securities to be included in the Registration, to review the
Registration Statement and all amendments and supplements thereto a reasonable
period of time prior to their filing, and shall not file any document in a form
to which such counsel reasonably objects.

            (d) Make available for inspection by any Investor that holds
Registrable Securities to be included in the Registration, any underwriters
participating in the offering pursuant to the Registration Statement and the
counsel, accountants or other agents retained by the Holder or any such
underwriter, all pertinent financial and other records, corporate documents and
properties of the Company, and cause the Company's officers, directors and
employees to supply all information reasonably requested by the Holder or any
such underwriters in connection with the Registration Statement.

            (e) If the Common Stock is then listed on a national securities
exchange, use its best efforts to cause the Registrable Securities to be listed
on such exchange if the listing of such Registrable Securities is then permitted
under the rules of such exchange, or if the Common Stock is not then listed on a
national securities exchange, use its best efforts to facilitate the quotation
of the Common Stock on Nasdaq.

            (f) Take all actions reasonably necessary to facilitate the timely
preparation and delivery of certificates (not bearing any restrictive legend)
representing the Registrable Securities to be sold pursuant to the Registration
Statement and to enable such certificates to be in such denominations and
registered in such names as the Holder or any underwriter may reasonably
request.

            (g) Take all other actions reasonably necessary to expedite and
facilitate disposition by the Holder of the Registrable Securities pursuant to
the Registration Statement.


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<PAGE>

            (h) With a view to making available to the Holder the benefits of
Rule 144 promulgated under the Act and any other rule or regulation of the
Commission that may at any time permit the Holder to sell securities of the
Company to the public without registration, the Company agrees to:

                  (i) make and keep public information available, as those terms
are understood and defined in Rule 144, at all times after 90 days after the
effective date of the first registration statement filed by the Company for the
offering of its securities to the general public;

                  (ii) file with the Commission in a timely manner all reports
and other documents required of the Company under the Securities Act and the
Exchange Act; and

                  (iii) furnish to the Holder, so long as the Holder owns any
Registrable Securities, forthwith upon request (a) a written statement by the
Company that it has complied with the reporting requirements of Rule 144, the
Act and the Exchange Act (at any time after it has become subject to such
reporting requirements), (b) a copy of the most recent annual or quarterly
report of the Company and such other reports and documents so filed by the
Company and (c) such other information as may be reasonably requested in
availing the Holder of any rule or regulation of the Commission which permits
the selling of any such securities without registration.

      3. ASSIGNMENT OF REGISTRATION RIGHTS. The right to cause the Company, and
the obligation of the Company, to register Registrable Securities pursuant to
this Agreement shall be automatically assigned by the Company and the Holders to
transferees or assignees of such securities; provided, that (a) the Company is,
within a reasonable time after such transfer, furnished written notice of (i)
the name and address of such transferee or assignee and (ii) the securities with
respect to which such registration rights are being assigned, (b) immediately
following such transfer such securities constitute "restricted securities" as
defined in Rule 144 under the Act, and (c) immediately following such transfer,
such transferee or assignee holds not less than 10,000 Registrable Securities
(as adjusted for stock splits, combinations or similar events).


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<PAGE>

      4.    MISCELLANEOUS.

            4.1   NOTICES.  Notices required or permitted to be given hereunder
shall be in writing and shall be deemed to be sufficiently given when personally
delivered or sent by registered mail, return receipt requested, addressed (i) if
to the Company, at American Psych Systems, Inc., One Democracy Plaza, 6701
Democracy Boulevard, Suite 555, Bethesda, Maryland 20817, Attention: Kenneth A.
Kessler, M.D., President; (ii) if to an Applewood Holder, c/o Applewood
Associates, L.P., 68 Wheatley Road, Brookville, New York 11545 Attention: Barry
Rubenstein, General Partner; (iii) if to Nazem, Nazem and Company IV, L.P., 645
Madison Avenue, New York, New York 10022, Attention: Jeffrey M. Krauss; (iv) if
to Oxford, 800 Connecticut Avenue, Norwalk, Connecticut 06854 Attention: Jeffrey
H. Boyd, Esq., or at such other address as each such party furnishes by notice
given in accordance with this section 4.1.

            4.2 WAIVER. Failure of any party to exercise any right or remedy
under this Agreement or otherwise, or delay by a party in exercising such right
or remedy, will not operate as a waiver thereof. No waiver will be effective
unless and until it is in writing and signed by the party giving the waiver.

            4.3 GOVERNING LAW. This Agreement shall be enforced, governed and
construed in all respects in accordance with the laws of the State of Delaware.
In the event that any provision of this Agreement is invalid or unenforceable
under any applicable statute or rule of law, then such provision shall be deemed
inoperative to the extent that it may conflict therewith and shall be deemed
modified to conform with such statue or rule of law. Any provision hereof which
may prove invalid or unenforceable under any law shall not affect the validity
or enforceability of any other provision hereof.

            4.4 ENTIRE AGREEMENT. This Agreement constitutes the entire
agreement between the parties hereto with respect to the subject matter hereof.
Any provision of this Agreement may be amended and the observance thereof may be
waived (either generally or in a particular instance and either retroactively or
prospectively), only by a writing executed by the Company and the Holders owning
more than sixty seven percent (67%) of all of the Registrable Securities. Any
amendment or waiver effected in accordance with this Section 4.4 shall be
binding upon the Holders and the Company.


                                     - 12 -

<PAGE>

            4.5 CONSENT OF APPLEWOOD HOLDERS. The Applewood Investors hereby
consent to the sale of the Notes and Warrants to Nazem and Oxford in accordance
with the terms of the Note Purchase Agreement, including the other agreements
referenced therein, and hereby waive and release their preemptive rights under
Section 4.8 of the Purchase Agreement which arise as a result of the sale of the
Notes and Warrants to Nazem and Oxford thereunder.

            4.6 AGREEMENT BINDING. Without further action of the parties, this
Amendment shall automatically become effective and binding upon the parties
hereto simultaneously with the closing of the sale of the Notes and Warrants to
the Investors under the Note Purchase Agreement.

            4.7 EXTENT OF AMENDMENT. Except to the extent expressly set forth
herein, this Amended and Restated Registration Rights Agreement does not amend,
modify, release or waive any of the terms of the Purchase Agreement, the Second
Purchase Agreement or the Third Purchase Agreement.

            4.8  COUNTERPARTS.  This Amended and Restated Registration Rights
Agreement may be executed in multiple counterparts.



      IN WITNESS WHEREOF, this Agreement has been executed as of the date and
year first above written.

                                    AMERICAN PSYCH SYSTEMS, INC.


                                    By:   /s/ Kenneth A. Kessler
                                          --------------------------
                                          Name:  Kenneth A. Kessler
                                          Title: President


APPLEWOOD ASSOCIATES, L.P.          SENECA VENTURES



By:   /s/ Barry Rubenstein          By:   /s/ Barry Rubenstein
      ------------------------            -----------------------------
      Name:  Barry Rubenstein             Name:  Barry Rubenstein
      Title: General Partner              Title: General Partner



                                     - 13 -
<PAGE>

WOODLAND PARTNERS                   WOODLAND VENTURE FUND



By:   /s/ Barry Rubenstein          By:   /s/ Barry Rubenstein
      ------------------------            -----------------------------
      Name:  Barry Rubenstein             Name:  Barry Rubenstein
      Title: General Partner              Title: General Partner



OXFORD HEALTH PLANS, INC.           NAZEM & COMPANY IV, L.P.

                                    By:  Nazem & Associates IV, L.P.,
                                    Its General Partner


By:  /s/ Jeffrey Boyd               By:  /s/ Jeffrey Krauss
     ------------------------            -----------------------------
     Name: Jeffrey H. Boyd                Name:  Jeffrey Krauss
     Title: Executive Vice                Title: General Partner
            President



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