Document:

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                                                                    EXHIBIT 10.6

                          STOCK OPTION GRANT NOTICE AND

                             STOCK OPTION AGREEMENT

      Clinical Data, Inc. (the "Company") grants to the holder listed below
("Participant") an option to purchase the number of shares of the Company's
common stock, par value $0.01 ("Shares") set forth below (the "Option") under
its 2005 Equity Incentive Plan (the "Plan"). The Option is subject to all of the
terms and conditions set forth in this Notice and in the Stock Option Agreement
attached as Exhibit A (the "Stock Option Agreement") and the Plan, which are
incorporated herein by reference. Unless otherwise defined herein, the terms
defined in the Plan shall have the same defined meanings in this Grant Notice
and the Stock Option Agreement.

Participant:                  _________________________________________

Grant Date:                   _________________________________________

Total Number of Shares
Subject to the Option:        _________________________________________

Exercise Price per Share:     _________________________________________

Total Exercise Price:         _________________________________________

Expiration Date:              _________________________________________

Type of Option:               Incentive Stock Option / Nonstatutory Stock Option

Vesting Schedule:             _________________________________________

      By signing below, Participant agrees to be bound by the terms and
conditions of the Plan, the Stock Option Agreement and this Grant Notice.
Participant has reviewed the Stock Option Agreement, the Plan and this Grant
Notice in their entirety, has had an opportunity to obtain the advice of counsel
prior to executing this Grant Notice and fully understands all provisions of
this Grant Notice, the Stock Option Agreement and the Plan. Participant hereby
agrees to accept as binding, conclusive and final all decisions or
interpretations of the Administrator of the Plan upon any questions arising
under the Plan or relating to the Option.

__________________________                            __________________________
Company                                               Participant

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                                    EXHIBIT A

                          To Stock Option Grant Notice

                             Stock Option Agreement

      The Company has granted to Participant an option under the Company's 2005
Equity Incentive Plan (the "Plan") to purchase the number of Shares indicated in
the attached Stock Option Grant Notice (the "Grant Notice").

                                    ARTICLE 1

                                     General

      1.1   Defined Terms. Capitalized terms not specifically defined herein
shall have the meanings specified in the Plan and the Grant Notice.

      1.2   Incorporation of Terms of Plan. The Option is subject to the terms
and conditions of the Plan which are incorporated herein by reference.

                                   ARTICLE 2

                                 Grant of Option

      2.1   Grant of Option. In consideration of Participant's past and/or
continued employment with or service to the Company or an Affilate and for other
good and valuable consideration, effective as of the Grant Date set forth in the
Grant Notice (the "Grant Date"), the Company irrevocably grants to Participant
the Option to purchase any part or all of an aggregate of the number of Shares
set forth in the Grant Notice, upon the terms and conditions set forth in the
Plan and this Agreement. Unless designated as a Nonstatutory Stock Option in the
Grant Notice, the Option shall be an Incentive Stock Option to the maximum
extent permitted by law.

      2.2   Exercise Price. The exercise price of the Shares subject to the
Option shall be as set forth in the Grant Notice, without commission or other
charge; provided, however, that the price per share of the Shares subject to the
Option shall not be less than 100% of the Fair Market Value of a Share on the
Grant Date. Notwithstanding the foregoing, if this Option is designated as an
Incentive Stock Option and Participant owns (within the meaning of Section
424(d) of the Code) more than 10% of the total combined voting power of all
classes of stock of the Company or any "subsidiary corporation" of the Company
or any "parent corporation" of the Company (each within the meaning of Section
424 of the Code), the price per share of the Shares subject to the Option shall
not be less than 110% of the Fair Market Value of a Share on the Grant Date.

      2.3   Consideration to the Company. In consideration of the grant of the
Option by the Company, Participant agrees to render faithful and efficient
services to the Company and its Affiliates. Nothing in the Plan or this
Agreement shall confer upon Participant any right to continue in the employ or
service of the Company or any Affiliate or shall interfere with or restrict in
any way the rights of the Company and its Affiliates, which rights are hereby
expressly reserved, to

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discharge or terminate the services of Participant at any time for any reason
whatsoever, with or without cause, except to the extent expressly provided
otherwise in a written agreement between the Company or its Affiliates and a
Participant.

                                    ARTICLE 3

                            Period of Exercisability

      3.1   Commencement of Exercisability.

            (a)   Subject to Sections 3.3, 5.7, 5.9, and 5.14, the Option shall
become vested and exercisable in such amounts and at such times as are set forth
in the Grant Notice.

            (b)   No portion of the Option that has not become vested and
exercisable at the date of Participant's Termination of Service shall thereafter
become vested and exercisable, except as may be otherwise provided by the
Administrator or as set forth in a written agreement between the Company and
Participant.

      3.2   Duration of Exercisability. The installments provided for in the
vesting schedule set forth in the Grant Notice are cumulative. Each such
installment which becomes vested and exercisable pursuant to the vesting
schedule set forth in the Grant Notice shall remain vested and exercisable until
it becomes unexercisable under Section 3.3.

      3.3   Expiration of Option. The Option may not be exercised to any extent
by anyone after the first to occur of the following events:

            (a)   The expiration of ten years from the Grant Date;

            (b)   If this Option is designated as an Incentive Stock Option and
Participant owned (within the meaning of Section 424(d) of the Code), at the
time the Option was granted, more than 10% of the total combined voting power of
all classes of stock of the Company or any "subsidiary corporation" of the
Company or any "parent corporation" of the Company (each within the meaning of
Section 424 of the Code), the expiration of five years from the Grant Date;

            (c)   The expiration of three months from the date of Participant's
Termination of Service, unless such termination occurs by reason of
Participant's death, Disability or Participant's discharge for cause;

            (d)   The expiration of one year from the date of Participant's
Termination of Service by reason of Participant's death or Disability; or

            (e)   The date of Participant's Termination of Service by the
Company or any of its Affiliates by reason of Participant's discharge for cause;

            (f)   Notwithstanding the foregoing, immediately prior to
a Change of Control (as defined in Section 5.14 of this Agreement) the

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unvested Options hereunder held by the Participant shall become 100% vested.
Following a Change of Control and following the Participant's subsequent
Termination of Service, the Options held by the Participant upon a Change of
Control shall expire upon the twelve month anniversary of the consummation of
such a Change of Control. Participant acknowledges that an Incentive Stock
Option exercised more than three months after Participant's Termination of
Employment, other than by reason of death or Disability, will be taxed as a
Nonstatutory Stock Option.

      3.4   Special Tax Consequences. Participant acknowledges that, to the
extent that the aggregate Fair Market Value (determined as of the time the
Option is granted) of all Shares with respect to which Incentive Stock Options,
including the Option, are exercisable for the first time by Participant in any
calendar year exceeds $100,000, the Option and such other options shall be
Nonstatutory Stock Options to the extent necessary to comply with the
limitations imposed by Section 422(d) of the Code. Participant further
acknowledges that the rule set forth in the preceding sentence shall be applied
by taking the Option and other Incentive Stock Options into account in the order
in which they were granted, as determined under Section 422(d) of the Code and
the Treasury Regulations thereunder.

                                    ARTICLE 4

                               Exercise of Option

      4.1   Person Eligible to Exercise. Except as provided in Sections 5.2(b)
and 5.2(c), during the lifetime of Participant, only Participant may exercise
the Option or any portion thereof. After the death of Participant, any
exercisable portion of the Option may, prior to the time when the Option becomes
unexercisable under Section 3.3, be exercised by Participant's personal
representative or by any person empowered to do so under the deceased
Participant's will or under the then applicable laws of descent and
distribution.

      4.2   Partial Exercise. Any exercisable portion of the Option or the
entire Option, if then wholly exercisable, may be exercised in whole or in part
at any time prior to the time when the Option or portion thereof becomes
unexercisable under Section 3.3.

      4.3   Manner of Exercise. The Option, or any exercisable portion thereof,
may be exercised solely by delivery to the Secretary of the Company or the
Secretary's office of all of the following prior to the time when the Option or
such portion thereof becomes unexercisable under Section 3.3:

            (a)   An Exercise Notice electronically or in writing signed by
Participant or any other person then entitled to exercise the Option or portion
thereof, stating that the Option or portion thereof is thereby exercised, such
notice complying with all applicable rules established by the Administrator.
Such notice shall be substantially in the form attached as Exhibit B to the
Grant Notice (or such other form as is prescribed by the Administrator);

            (b)   The receipt by the Company of full payment for the Shares with
respect to which the Option or portion thereof is exercised, including payment
of any applicable withholding tax, which may be in one or more of the forms of
consideration permitted under Section 4.4;

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            (c)   A bona fide written representation and agreement, in such form
as is prescribed by the Administrator, signed by Participant or the other person
then entitled to exercise such Option or portion thereof, stating that the
Shares are being acquired for Participant's own account, for investment and
without any present intention of distributing or reselling said Shares or any of
them except as may be permitted under the Securities Act of 1933 (the
"Securities Act") and then applicable rules and regulations thereunder and any
other applicable law, and that Participant or other person then entitled to
exercise such Option or portion thereof will indemnify the Company against and
hold it free and harmless from any loss, damage, expense or liability resulting
to the Company if any sale or distribution of the Shares by such person is
contrary to the representation and agreement referred to above. The
Administrator may, in its absolute discretion, take whatever additional actions
it deems appropriate to ensure the observance and performance of such
representation and agreement and to effect compliance with the Securities Act
and any other federal or state securities laws or regulations and any other
applicable law. Without limiting the generality of the foregoing, the
Administrator may require an opinion of counsel acceptable to it to the effect
that any subsequent transfer of Shares acquired on an Option exercise does not
violate the Securities Act, and may issue stop-transfer orders covering such
Shares. Share certificates evidencing Shares issued on exercise of the Option
shall bear an appropriate legend referring to the provisions of this subsection
(c) and the agreements herein. The written representation and agreement referred
to in the first sentence of this subsection (c) shall, however, not be required
if the Shares to be issued pursuant to such exercise have been registered under
the Securities Act, and such registration is then effective in respect of such
Shares; and

            (d)   In the event the Option or portion thereof shall be exercised
under Section 4.1 by any person or persons other than Participant, appropriate
proof of the right of such person or persons to exercise the Option.

      4.4   Method of Payment. Payment of the exercise price shall be by any of
the following, or a combination thereof, at the election of the Participant:

            (a)   by cash, check, or other cash equivalent approved by the
Administrator;

            (b)   by the tendering of other Shares to the Company or the
attestation to the ownership of the Shares that otherwise would be tendered to
the Company in exchange for the Company's reducing the number of Shares issuable
upon the exercise of the Option. Shares tendered or attested to in exchange for
Shares issued under the plan must be held by the Service Provider for at least
six months prior to their tender or their attestation to the Company and may not
be shares of Restricted Stock at the time they are tendered or attested to. The
Administrator shall determine acceptable methods for tendering or attesting to
Shares to exercise an Option under the Plan and may impose such limitations and
prohibitions on the use of Shares to exercise Options as it deems appropriate.
For purposes of determining the amount of the Option price satisfied by
tendering or attesting to Shares, such Shares shall be valued at their Fair
Market Value on the date of tender or attestation, as applicable; or

            (c)   by using such other methods of payment that the Administrator,
at its discretion, deems appropriate from time to time.

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      4.5   Conditions to Issuance of Stock Certificates. The Shares deliverable
upon the exercise of the Option, or any portion thereof, may be either
previously authorized but unissued Shares or issued Shares which have then been
reacquired by the Company. Such Shares shall be fully paid and nonassessable.
The Company shall not be required to issue or deliver any Shares purchased upon
the exercise of the Option or portion thereof prior to fulfillment of all of the
following conditions:

            (a)   The admission of such Shares to listing on all stock exchanges
on which such Shares are then listed;

            (b)   The completion of any registration or other qualification of
such Shares under any state or federal law or under rulings or regulations of
the Securities and Exchange Commission or of any other governmental regulatory
body, which the Administrator shall, in its absolute discretion, deem necessary
or advisable;

            (c)   The obtaining of any approval or other clearance from any
state or federal governmental agency which the Administrator shall, in its
absolute discretion, determine to be necessary or advisable;

            (d)   The receipt by the Company of full payment for such Shares,
including payment of any applicable withholding tax, which may be in one or more
of the forms of consideration permitted under Section 4.4; and

            (e)   The lapse of such reasonable period of time following the
exercise of the Option as the Administrator may from time to time establish for
reasons of administrative convenience.

      4.6   Rights as Stockholder. The holder of the Option shall not be, nor
have any of the rights or privileges of, a stockholder of the Company in respect
of any Shares purchasable upon the exercise of any part of the Option unless and
until such Shares shall have been issued by the Company to such holder (as
evidenced by the appropriate entry on the books of the Company or of a duly
authorized transfer agent of the Company). No adjustment will be made for a
dividend or other right for which the record date is prior to the date the
Shares are issued, except as provided in Section 2.3 of the Plan.

                                    ARTICLE 5

                                Other Provisions

      5.1   Administration. The Administrator shall have the power to interpret
the Plan and this Agreement and to adopt such rules for the administration,
interpretation and application of the Plan as are consistent therewith and to
interpret, amend or revoke any such rules. All actions taken and all
interpretations and determinations made by the Administrator in good faith shall
be final and binding upon Participant, the Company and all other interested
persons. No member of the Administrator shall be personally liable for any
action, determination or interpretation made in good faith with respect to the
Plan, this Agreement or the Option.

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      5.2   Option Not Transferable.

            (a)   Subject to Section 5.2(b), the Option may not be sold,
pledged, assigned or transferred in any manner other than by will or the laws of
descent and distribution, unless and until the Shares underlying the Option have
been issued, and all restrictions applicable to such Shares have lapsed. Neither
the Option nor any interest or right therein shall be liable for the debts,
contracts or engagements of Participant or his or her successors in interest or
shall be subject to disposition by transfer, alienation, anticipation, pledge,
encumbrance, assignment or any other means whether such disposition be voluntary
or involuntary or by operation of law by judgment, levy, attachment, garnishment
or any other legal or equitable proceedings (including bankruptcy), and any
attempted disposition thereof shall be null and void and of no effect, except to
the extent that such disposition is permitted by the preceding sentence.

            (b)   Notwithstanding any other provision in this Agreement, with
the consent of the Administrator and to the extent the Option is not intended to
qualify as an Incentive Stock Option, the Option may be transferred to one or
more members of the Participant's immediate family, to trusts for the benefit of
such family members, or to partnerships in which such family members are the
only partners, or to limited liability companies in which such family members
are the only members (each a "Permitted Transferee"), provided that the
Permitted Transferee agrees in writing with the Company to be bound by all of
the terms and conditions of the Plan and this Option Agreement.

            (c)   Unless transferred to a Permitted Transferee in accordance
with Section 5.2(b), during the lifetime of Participant, only the Participant
may exercise the Option or any portion thereof. Subject to such conditions and
procedures as the Administrator may require, a Permitted Transferee may exercise
the Option or any portion thereof during Participant's lifetime. After the death
of Participant, any exercisable portion of the Option may, prior to the time
when the Option becomes unexercisable under Section 3.3, be exercised by
Participant's personal representative or by any person empowered to do so under
the deceased Participant's will or under the then applicable laws of descent and
distribution.

      5.3   Restrictive Legends and Stop-Transfer Orders.

            (a)   The share certificate or certificates evidencing the Shares
purchased hereunder shall be endorsed with any legends that may be required by
state or federal securities laws.

            (b) Participant agrees that, in order to ensure compliance with the
restrictions referred to herein, the Company may issue appropriate "stop
transfer" instructions to its transfer agent, if any, and that, if the Company
transfers its own securities, it may make appropriate notations to the same
effect in its own records.

            (c)   Company shall not be required: (i) to transfer on its books
any Shares that have been sold or otherwise transferred in violation of any of
the provisions of this Agreement, or (ii) to treat as owner of such Shares or to
accord the right to vote or pay dividends to any purchaser or other transferee
to whom such Shares shall have been so transferred.

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      5.4   Shares to Be Reserved. The Company shall at all times during the
term of the Option reserve and keep available such number of Shares as will be
sufficient to satisfy the requirements of this Agreement.

      5.5   Notices. Any notice to be given under the terms of this Agreement to
the Company shall be addressed to the Company in care of the Secretary of the
Company at the address given beneath the signature of the Company's authorized
officer on the Grant Notice, and any notice to be given to Participant shall be
addressed to Participant at the address given beneath Participant's signature on
the Grant Notice. By a notice given pursuant to this Section 5.5, either party
may hereafter designate a different address for notices to be given to that
party.

      5.6   Titles. Titles are provided herein for convenience only and are not
to serve as a basis for interpretation or construction of this Agreement.

      5.7   Stockholder Approval. The Plan will be submitted for approval by the
Company's stockholders within twelve months after the date the Plan was
initially adopted by the Board. The Option may not be exercised to any extent by
anyone prior to the time when the Plan is approved by the stockholders, and if
such approval has not been obtained by the end of said twelve month period, the
Option shall thereupon be canceled and become null and void.

      5.8   Governing Law; Severability. This Agreement shall be administered,
interpreted and enforced under the laws of the State of Delaware, without regard
to the conflicts of law principles thereof. Should any provision of this
Agreement be determined by a court of law to be illegal or unenforceable, the
other provisions shall nevertheless remain effective and shall remain
enforceable.

      5.9   Conformity to Securities Laws. Participant acknowledges that the
Plan is intended to conform to the extent necessary with all provisions of the
Securities Act and the Exchange Act and any and all regulations and rules
promulgated by the Securities and Exchange Commission thereunder, and state
securities laws and regulations. Notwithstanding anything herein to the
contrary, the Plan shall be administered, and the Option is granted and may be
exercised, only in such a manner as to conform to such laws, rules and
regulations. To the extent permitted by applicable law, the Plan and this
Agreement shall be deemed amended to the extent necessary to conform to such
laws, rules and regulations.

      5.10  Amendments. This Agreement may not be modified, amended or
terminated except by an instrument in writing, signed by Participant or such
other person as may be permitted to exercise the Option pursuant to Section 4.1
and by a duly authorized representative of the Company.

      5.11  Successors and Assigns. The Company may assign any of its rights
under this Agreement to single or multiple assignees, and this Agreement shall
inure to the benefit of the successors and assigns of the Company. Subject to
the restrictions on transfer herein set forth in Section 5.2, this Agreement
shall be binding upon Participant and his or her heirs, executors,
administrators, successors and assigns.

      5.12  Notification of Disposition. If this Option is designated as an
Incentive Stock Option, Participant shall give prompt notice to the Company of
any disposition or other transfer of any Shares acquired under this Agreement if
such disposition or transfer is made (a) within two years

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from the Grant Date with respect to such Shares or (b) within one year after the
transfer of such Shares to him. Such notice shall specify the date of such
disposition or other transfer and the amount realized, in cash, other property,
assumption of indebtedness or other consideration, by Participant in such
disposition or other transfer.

      5.13  Limitations Applicable to Section 16 Persons. Notwithstanding any
other provision of the Plan or this Agreement, if Participant is subject to
Section 16 of the Exchange Act, the Plan, the Option and this Agreement shall be
subject to any additional limitations set forth in any applicable exemptive rule
under Section 16 of the Exchange Act (including any amendment to Rule 16b-3 of
the Exchange Act) that are requirements for the application of such exemptive
rule. To the extent permitted by applicable law, this Agreement shall be deemed
amended to the extent necessary to conform to such applicable exemptive rule.

      5.14  Change of Control. A Change of Control means the consummation of or
entering into by the Company of any agreement, contract, plan or understanding
with respect to (i) the merger, consolidation or reorganization of the Company
into or with another corporation in a business combination transaction in which
the Company is the target of such transaction (except one in which the holders
of capital stock of the Company immediately prior to such merger, consolidation
or reorganization continue to beneficially own (within the meaning of Rule 13d-3
of the Exchange Act) at least a majority of the voting power of the capital
stock of the surviving corporation), (ii) any sale, lease or transfer of all or
substantially all of the capital stock, assets or intellectual property of the
Company (except (A) to an entity majority-owned or controlled by the Company or
by any of the holders of capital stock of the Company, or (B) in any transaction
structured as a spin-off or divestiture of assets or intellectual property of
the Company or its subsidiaries ), (iii) any other transaction other than an
equity financing transaction or series of related equity financing transactions
pursuant to or as a result of which an individual, entity or group (within the
meaning of Sections 13(d)(3) or 14(d)(2) of the Act) acquires or beneficially
owns capital stock of the Company representing a majority of the Company's
outstanding voting power, or (iv) a complete or substantial liquidation or
dissolution of the Company. In the event of any interpretation of this
definition, the Board of Directors of the Company, upon advice of legal counsel,
shall have final and conclusive authority, so long as such authority is
exercised in good faith. In the event of a Change of Control, the Company, the
Board, or the board of directors of any corporation assuming the obligations of
the Company may, in its discretion, take any one or more of the following
actions:

            (a)   provide that the Option shall be assumed, or an equivalent
option shall be substituted, by the acquiring or succeeding corporation (or its
Affiliate);

            (b)   upon written notice to the Participant, provide that any
unexercised portion of the Option will terminate immediately prior to the
consummation of the Change of Control, unless exercised by the Participant
within a specified period following the date of such notice;

            (c)   terminate the Option in exchange for a cash payment equal to
the excess of the Fair Market Value of the Shares subject to the Option (to the
extent then exercisable) over the exercise price thereof;

            (d)   terminate the Option in exchange for the right to participate
in any stock option or other employee benefit plan of any successor corporation
(giving proper credit for the

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portion of the Option, which has otherwise vested and become exercisable prior
to any such Change of Control;

            (e)   in the event of a merger under the terms of which holders of
Shares will receive upon consummation thereof a cash payment for each Share
surrendered in the merger (the "Merger Price"), make or provide for a cash
payment to the Participant equal to the difference between (x) the Merger Price
times the number of Shares subject to the Option (to the extent then exercisable
at prices not in excess of the Merger Price) and (y) the aggregate exercise
price of the Option in exchange for the termination of the Option; or

            (f)   provide that the Option shall become exercisable in full
immediately prior to such Change of Control.

      5.15  Entire Agreement. The Plan and this Agreement (including all
Exhibits hereto) constitute the entire agreement of the parties and supersede in
their entirety all prior undertakings and agreements of the Company and
Participant with respect to the subject matter hereof.

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                                    EXHIBIT B

                          To Stock Option Grant Notice

                             Form of Exercise Notice

      Effective as of today, _____________, 20__, the undersigned
("Participant") hereby elects to exercise Participant's option to purchase the
number of shares of common stock specified below (the "Shares") of Clinical Data
Inc., a Delaware corporation (the "Company"), under and pursuant to the 2005
Equity Incentive Plan (the "Plan") and the Stock Option Grant Notice and Stock
Option Agreement dated as of (the "Option Agreement"). Capitalized terms used
herein without definition shall have the meanings given in the Plan and, if not
defined in the Plan, the Option Agreement.

Grant Date:                                        _____________________________

Number of Shares as to which Option is Exercised:  _____________________________

Exercise Price per Share:                          _____________________________

Total Exercise Price:                              _____________________________

Certificate to be issued in name of:               _____________________________

Payment delivered:                                 $ ___________________________
(Representing herewith:  the full exercise
price for the Shares, as well as any applicable
withholding tax)

Form of Payment:
                                                   _____________________________
                                                   (Please Specify)

Type of Option:  [  ] Incentive Stock Option       [ ] Nonstatutory Stock Option

      Participant acknowledges that Participant has received, read and
understood the Plan and the Option Agreement. Participant agrees to abide by and
be bound by their terms and conditions. Participant understands that Participant
may suffer adverse tax consequences as a result of Participant's purchase or
disposition of the Shares. Participant represents that Participant has consulted
with any tax consultants Participant deems advisable in connection with the
purchase or disposition of the Shares and that Participant is not relying on the
Company for any tax advice. The Plan and Option Agreement are incorporated
herein by reference. This Agreement, the Plan and the Option Agreement
constitute the entire agreement of the parties and supersede in their entirety
all prior undertakings and agreements of the Company and Participant with
respect to the subject matter hereof.

By: ________________________________           Accepted: _______________________
    [_______________________________]                 By: ______________________

                                       11<PAGE>

                                                                   EXHIBIT 10.31

                       [GENAISSANCE PHARMACEUTICALS LOGO]

                                               May 25, 2006

Kevin Rakin
14 Side Hill Road
Westport, CT 06880

Dear Kevin:

      Since the termination of your employment with Genaissance Pharmaceuticals,
Inc. (the "Company") in October 2005, you, the Company and the Company's parent,
Clinical Data, Inc. (the "Parent"), have disputed amounts owed to you under your
employment agreement dated January 1, 2004 (the "Employment Agreement").

      This letter follows up on the negotiations we have had concerning the
separation of your employment with the Company and, among other things, is
intended as a resolution of the above-mentioned disputes. The Company is
offering to you certain severance and other terms and benefits in exchange for
the general release of claims and other terms set forth below. The specific
terms of our agreement (the "Agreement") are as follows:

      1.    TERMINATION OF EMPLOYMENT. Your employment with the Company
terminated effective October 31, 2005 (your "Termination Date"). The Company has
paid you all wages earned and any accrued and unused vacation time in accordance
with the Company's policies through your Termination Date.

      2.    SEVERANCE PAY AND BENEFITS.

            (a)   Severance Pay. The Company (a) has paid you a one-time lump
sum payment in the total gross amount of one hundred thousand dollars ($100,000)
on or about the date hereof and (b) will pay you a one-time lump sum payment in
the total gross amount of four hundred twenty-three thousand five hundred
dollars ($423,500), in the case of both (a) and (b) less appropriate income and
employment tax withholdings as determined by the Company in good faith and any
authorized deductions (the "Severance Payment"); provided, however that no
payment shall be made under clause (b) above until the later of either the
Company's next regular payroll period following May 31, 2006 or the expiration
of the Revocation Period defined in paragraph 8 below. In addition, the Company
agrees that it shall not offset from the Severance Payment the value of the
2,500 shares of the Parent's common stock, par value $0.01 (the "Common Stock")
and the 1,250 warrants to purchase Common Stock issued to you on or about
November 17, 2005 (valued at the time of investment at forty-eight thousand nine
hundred six dollars and twenty-five cents ($48,906.25)) which may be subject to
taxation in accordance with applicable law.

<PAGE>

Kevin Rakin
Page 2

            (b)   Taxes and Filing. Except as provided by Section 13(b)
subparagraphs (iii) through (vi) of your Employment Agreement, you acknowledge
that you shall be solely responsible for the satisfaction of any income,
employment or other taxes, interest or penalties that may be assessed against
you. Neither the Company nor its affiliates, nor any of their directors, agents,
or employees shall have any obligation to indemnify or hold you harmless from
any or all of such taxes. You agree to indemnify and hold the Company harmless
from any claims and expenses the Company may incur as a result of any failure by
you to pay taxes which might be due as a result of receiving compensation from
the Company under this Agreement or otherwise. You shall be responsible for
making all filings under Section 16 of the Securities and Exchange Act of 1934,
as amended.

            (c)   Legal fees. The Company agrees to reimburse you for legal fees
and expenses actually incurred in connection with the negotiation of this
Agreement up to a maximum amount of fifteen thousand dollars ($15,000). To
receive reimbursement for legal fees and expenses contemplated by this paragraph
2(c), you must submit invoices for such fees and expenses (with any privileged
information redacted) to Caesar Belbel, the Company's Executive Vice President
and Chief Legal Counsel, at the Company's headquarters. Payment for legal fees
will be made on the Company's next regularly scheduled payroll period following
submission and review of the fee invoices.

            (d)   Health and Dental Insurance. Upon the termination of your
employment, you and your dependents may be eligible to continue your health
and/or dental insurance coverage under Company-sponsored plans, if any, pursuant
to the federal law known as COBRA. You have elected COBRA continuation coverage.
The Company has paid the full monthly premium cost and any monthly
administrative fee for such continuation coverage (the "COBRA Premium") since
the Termination Date and will continue pay the COBRA Premium for a total period
of 18 months following your Termination Date. Your rights and obligations under
such insurance plans shall be governed by the specific terms of the plans and
COBRA. Information concerning COBRA rights, coverage and election has been sent
to you under separate cover. In the event you obtain health and/or dental
insurance coverage through other employment prior to the expiration of the
18-month period of COBRA Premium payments described herein, the Company's
obligation to continue to provide such COBRA Premium payments shall cease as of
the effective date of such coverage. Should you obtain such coverage, you agree
to promptly notify Mr. Belbel in writing at the Company's headquarters.

            (e)   Accelerated Vesting of Stock Options and Extension of Exercise
Period. The parties agree that, pursuant to Section 13(c) of your Employment
Agreement, your unvested stock options and restricted stock of the Parent vested
completely effective as of your Termination Date. You may exercise any of the
vested options of the Parent as set forth on the attached Exhibit A until and
including October 31, 2006. Except for the accelerated vesting and exercise
period described in this paragraph 2(e), your rights and obligations concerning
all options shall be governed by the terms and procedures of the applicable
option grants and agreements.

<PAGE>

Kevin Rakin
Page 3

            (f)   Other Benefits. Except as specifically set forth in this
Agreement, your right to, and participation in, all employee benefit plans of
the Company and the Parent terminated as of your Termination Date in accordance
with the specific terms of each plan.

            (g)   Consulting Arrangements. (i) You, the Company and the Parent
have been operating under a consulting arrangement in which you devote up to
forty percent (40%) of your full business time and effort to matters concerning
the Company and/or the Parent, as directed by the Parent's Chief Executive
Officer, in exchange for a payment of twenty thousand dollars ($20,000) per each
full month of service, payable monthly in arrears. This consulting arrangement
terminated effective April 15, 2006 and the parties agree that the payment
in-full for your services for one-half of the month of April was ten thousand
dollars ($10,000).

            (ii) Effective April 16, 2006, the parties will operate under a new
consulting arrangement that will continue through March 31, 2007, during which
time you shall provide consulting services to the Company by mutual agreement
between you and the Parent's Chief Executive Officer on an as-needed basis, but
in no event in excess of forty percent (40%) of your full business time and
effort per month. As compensation for your past services as a consultant and for
future services as a consultant described in this subparagraph (ii), the Company
agrees to grant to you seventy thousand (70,000) fully vested non-qualified
stock options to purchase Common Stock with an exercise price equal to the
closing price of the Common Stock on the Nasdaq National Market as of the date
of the grant. These options shall be issued pursuant to the Parent's 2005 Equity
Incentive Plan and will be subject to the standard non-qualified stock option
grant agreement promulgated thereunder. The term of these options shall be 10
years. These options shall be exercisable at any time during your service as a
director of the Parent and for five (5) years following the termination of your
service as a director of the Parent, subject in all cases to the 10-year term of
the options. Your rights and obligations concerning such stock options shall be
governed in all respects by the terms and procedures of the 2005 Equity
Incentive Plan and the applicable option grant agreement. The date of the grant
under this paragraph 2(g)(ii) shall be May 12, 2006.

            (j)   Compensation for Service as Director. Upon the conclusion of
the initial consulting arrangement described in paragraph 2(g)(i) above, and
provided that you are not employed by the Parent or the Company, you shall be
eligible to receive director's fees for your service on the Board on the same
terms, conditions and basis as other non-employee directors of the Board on a
pro-rated basis (pro-rated monthly) through the date of the Company's next
annual meeting of stockholders, currently scheduled for September 21, 2006.

      3.    RETURN OF COMPANY PROPERTY. You agree to return to the Company: (a)
all originals and copies of all proprietary or confidential information and
trade secrets of the Company and the Parent, whether in print, electronic or
other form;

<PAGE>

Kevin Rakin
Page 4

(b) all originals and copies of Company and Parent files and customer files,
whether in print or electronic form; (c) all identification cards, keys, or
other means of access to the Company or Parent; and (d) any other property of
the Company and Parent in your possession, custody or control (collectively
"Company Property"). The parties expressly agree that the term "Company
Property" shall not include information, materials and things that you must
retain in your possession in order to reasonably discharge your duties under
your consulting arrangement with the Company or in your role on the Clinical
Data Board of Directors. You represent that as of the date of this letter you
have returned all such Company Property.

      4.    NONDISPARAGEMENT. You agree that you will not make, and that you
will not allow or instruct any other party to make, whether in oral, print,
electronic or other form, any false, disparaging or derogatory remarks about, or
refer negatively to your association with, the Parent, the Company, their
affiliates, their products and services, their past or present officers,
directors, trustees, employees or any other Released Party defined in paragraph
7.

      5.    CONFIDENTIALITY. You agree to keep the existence, terms and
negotiations of this Agreement strictly confidential and shall not disclose
these matters to anyone, in words or in substance, except: (a) to your
attorneys, financial advisors, and immediate family members, provided that they
first agree to keep all such matters confidential; (b) to any taxing authority;
and (c) to the extent required by law or to the extent necessary to enforce
rights under this Agreement; provided however that if you anticipate or are
required to make disclosure pursuant to this subsection, you shall inform the
Parent's Chief Executive Officer in advance of any disclosure at least ten (10)
days prior to such disclosure whenever possible, and where not possible, you
shall provide as much advance notice as possible. Nothing in this Agreement
shall limit the rights of any government agency or any party's right of access
to, participation or cooperation with any government agency.

      6.    NON-FILING OF COMPLAINT OR CHARGES. You represent that you have not
filed or asserted any cause of action, claim, charge or other action or
proceeding against the Company or any Released Party, defined in paragraph 7.

      7.    GENERAL RELEASE. As a material inducement to the Parent and the
Company to enter into this Agreement, and in consideration of the severance pay
and benefits and other good and valuable consideration, the receipt and
sufficiency is hereby acknowledged, you, on behalf of yourself, your heirs,
administrators, representatives, executors, successors, and assigns, hereby
irrevocably and unconditionally release, acquit, and forever discharge
Genaissance Pharmaceuticals, Inc. and its predecessors, parents, subsidiaries,
affiliates, divisions, any related entity, successors and assigns, and all of
their current and former agents, officers, directors, shareholders, employees,
members, trustees, fiduciaries, representatives, attorneys and all persons
acting by, through, under or in concert with any of them (the "Released
Parties") from any and all charges, complaints, claims, liabilities,

<PAGE>

Kevin Rakin
Page 5

obligations, promises, agreements, damages, causes of action, suits, demands,
losses, debts, and expenses of any nature whatsoever, known or unknown
("Claims") which you have, had or claim to have against any Released Party up to
and including the Effective Date of this Agreement. This General Release of
Claims shall include, without limitation, Claims relating to your employment and
separation from employment with the Company, Claims of discrimination under the
common law or any federal or state statute (including, without limitation, the
Civil Rights Act of 1964, the Americans with Disabilities Act and the Age
Discrimination in Employment Act, all as amended), Claims for wrongful
discharge, Claims for the payment of any salary, wages, bonuses, commissions,
vacation pay, severance pay or benefits, Claims relating to stock or stock
options, Claims relating to the payment of taxes, including without limitation
any taxes that may be assessed under Sections 409A or 4999 of the Internal
Revenue Code, Claims of detrimental reliance, and all other statutory, common
law, tort, contract or other Claims of any nature whatsoever, to the fullest
extent permitted by law. This General Release of Claims does not apply to any
Claims concerning a breach of this Agreement or any claims arising after the
Effective Date of this Agreement. With respect to the Claims you are waiving
herein, you acknowledge that you are waiving your right to receive money or any
other relief in any action instituted by you or on your behalf by any other
person, entity or government agency. To the fullest extent permitted by law, you
further agree that if any agency or court assumes jurisdiction over any
complaint or charge on your behalf against any Released Party, you will request
immediate dismissal of the matter.

      8.    NOTICE AND RIGHT TO CONSIDER. You are advised to consult with an
attorney before executing this Agreement. You represent and acknowledge that you
have been advised to consult with an attorney and that you have been represented
by the attorney of your choosing, Louis A. Rodriques, Esquire, during the
negotiation of this Agreement, that you have consulted with your attorney before
executing this Agreement, that you have carefully read and fully understand all
of the provisions of this Agreement and that you are voluntarily entering into
this Agreement. You acknowledge that you have been given up to twenty-one (21)
days from the date you receive this letter to complete your review and sign it.
You acknowledge that if you sign this Agreement prior to the expiration of the
twenty-one (21) day period that you did so voluntarily. You will also have seven
(7) days following your execution of this Agreement to revoke it (the
"Revocation Period"). If you wish to revoke your acceptance of this Agreement,
you must submit your revocation in writing to the Company's Chief Executive
Officer within the time period set forth above. The terms of this Agreement
shall not become effective or enforceable until after the expiration of the
Revocation Period. The effective date of this Agreement shall be the day
immediately following the expiration of the Revocation period (the "Effective
Date").

      9.    COOPERATION. You agree that you will cooperate and assist the Parent
and the Company in the future in the event that the Parent or the Company is
presented with legal issues as to which you have relevant information and
knowledge. To the extent such cooperation is required, the Parent and the
Company each agrees

<PAGE>

Kevin Rakin
Page 6

to reimburse you for reasonable out-of-pocket expenses actually incurred in
connection with providing such cooperation so long as such expenses are approved
in advance.

      10.   ENTIRE AGREEMENT. This Agreement constitutes the full understanding
and entire Agreement between you, the Parent and the Company and supersedes any
other agreements of any kind, whether oral or written, formal or informal;
provided however, that you will adhere to and honor all covenants and
obligations to the Company, its parents, its affiliates and its successors and
assigns as may be set forth in any agreement between you and the Company which
survive termination of your employment, including, without limitation, that you
shall remain bound by your continuing obligations to preserve the Company's
trade secrets, intellectual property, and confidential information and that you
shall remain bound by Sections 7 through 11 of your Employment Agreement, which
contain non-competition, non-solicitation, confidentiality and inventions
covenants for the period through October 31, 2006. Notwithstanding the
foregoing, you acknowledge that, while a member of the Parent's board of
directors, you continue to be subject to your fiduciary obligations to the
Parent, the Company and their stockholders and that nothing in this agreement or
in your Employment Agreement purports to alter such obligations. You acknowledge
and agree that, except for those obligations contained herein, the Parent and
the Company have fulfilled and satisfied all of their obligations under any and
all agreements between you and the Company including, without limitation, the
Employment Agreement, and neither the Parent nor the Company has further
obligations thereunder, or under any other agreements, employment or otherwise.
No covenants, agreements, representations or warranties of any kind whatsoever
have been made by any party, except as specifically set forth in this Agreement.
The parties represent and acknowledge that in executing this Agreement they do
not rely and have not relied upon any other promise, inducement, representation
or statement, whether oral or in writing, made by the other or by the other's
agents, representatives, or attorneys with regard to the subject matter, basis
or effect of this Agreement. This Agreement may be modified only by a writing
signed by the parties.

      11.   MISCELLANEOUS. The parties agree that the failure of a party at any
time to require performance of any provision of this Agreement shall not affect,
diminish, obviate or void in any way the party's full right or ability to
require performance of the same or any other provision of this Agreement at any
time thereafter.

      This Agreement shall inure to the benefit of and shall be binding upon
you, your heirs, administrators, representatives, executors, successors and
assigns and upon the successors and assigns of the Company.

      This Agreement shall be construed in accordance with and governed by the
laws of the State of Connecticut.

      Should any portion, term or provision of this Agreement be declared or
determined by any court to be illegal, invalid or unenforceable, the validity or
the

<PAGE>

Kevin Rakin
Page 7

remaining portions, terms and provisions shall not be affected thereby, and the
illegal, invalid or unenforceable portion, term or provision shall be deemed not
to be part of this Agreement.

      The headings of the paragraphs of this Agreement are for convenience only
and are not binding on any interpretation of this Agreement.

                                      * * *

<PAGE>

Kevin Rakin
Page 8

      If you wish to accept this Agreement, please sign and date the Agreement
below and return it to me within the time period specified in paragraph 8.

      We wish you every success for the future.

                                        Sincerely,

                                        /s/ Caesar J. Belbel
                                        ----------------------------------------
                                        Caesar J. Belbel
                                        Executive Vice President and
                                        Chief Legal Officer, Clinical Data, Inc.

BY SIGNING THIS AGREEMENT, I STATE THAT I HAVE READ IT, I UNDERSTAND IT, I HAVE
REVIEWED IT WITH MY ATTORNEY, I AGREE WITH EVERYTHING IN IT AND I HAVE SIGNED IT
KNOWINGLY AND VOLUNTARILY.

    /s/ Kevin Rakin
-------------------------------------
Kevin Rakin

Date: May 25, 2006

cc:   Louis A. Rodriques, Esq.
      Bingham McCutchen LLP
      150 Federal Street
      Boston, MA 02110

<PAGE>

                                    EXHIBIT A

<TABLE>
<CAPTION>
                                                                             ORIGINAL TERM TO
                                                                               EXERCISE CLDA
                                                                             OPTIONS (PURSUANT
                        GENAISSANCE                        ORIGINAL CLDA    TO SECTION 13(c) OF
                     OPTIONS GRANTED &   CONVERTED TO   EXERCISE PRICE PER      EMPLOYMENT
ORIGINAL GRANT DATE       VESTED         CLDA OPTIONS          SHARE            AGREEMENT)
-------------------  -----------------  --------------  ------------------  -------------------
<S>                  <C>                <C>             <C>                 <C>
     10-Apr-00            400,000               26,000       $ 184.62             31-Oct-06
     22-Oct-01            100,000                6,500       $  58.47             31-Oct-06
     21-Mar-02             50,000                3,250       $  38.47             31-Oct-06
      2-May-02             50,000                3,250       $  76.93             31-Oct-06
     15-Nov-02             75,000                4,875       $  13.08             31-Oct-06
      9-Dec-03            106,043                6,892       $  39.39             31-Oct-06
      9-Dec-03             33,957                2,207       $  39.39             31-Oct-06
     27-Apr-04             10,280                  668       $  57.54             31-Oct-06
     27-Apr-04             49,720                3,231       $  57.54             31-Oct-06
      7-Jan-05             41,141                2,674       $  33.85             31-Oct-06
      7-Jan-05             93,859                6,100       $  33.85             31-Oct-06
                                        --------------
                                        Total = 65,647
                                        ==============
</TABLE>

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