<PAGE>

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D. C. 20549
                           --------------------------

                                    FORM 8-K

                                 CURRENT REPORT

                       Pursuant to Section 13 or 15(d) of
                       The Securities Exchange Act of 1934
                            -------------------------

        Date of Report (Date of earliest event reported): August 15, 2006

                          MERRILL LYNCH DEPOSITOR, INC.
                 (ON BEHALF OF PREFERREDPLUS TRUST SERIES QWS-1)
             (Exact name of registrant as specified in its charter)

            DELAWARE               001-16727                    13-3891329
        (State or other          (Commission                (I. R. S. Employer
        jurisdiction  of          File Number)              Identification No.)
         incorporation)

     WORLD FINANCIAL CENTER,                                       10080
       NEW YORK, NEW YORK                                       (Zip Code)
      (Address of principal
       executive offices)
                           --------------------------

       Registrant's telephone number, including area code: (212) 449-1000


                      INFORMATION TO BE INCLUDED IN REPORT


Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions (see General Instruction A.2.):

[  ]  Written communications pursuant to Rule 425 under the Securities Act (17
      CFR 230.425)

[  ]  Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17
      CFR 240.14a-12)

[  ]  Pre-commencement communications pursuant to Rule 14d-2(b) under the
      Exchange Act (17 CFR 240.14d-2(b))

[  ]  Pre-commencement communications pursuant to Rule 13e-4(c) under the
      Exchange Act (17 CFR 240.13e-4(c))


<PAGE>

SECTION 1.    REGISTRANT'S BUSINESS AND OPERATIONS

              Not applicable.

SECTION 2.    FINANCIAL INFORMATION

              Not applicable.

SECTION 3.    SECURITIES AND TRADING MARKETS

              Not applicable.

SECTION 4.    MATTERS RELATED TO ACCOUNTANTS AND FINANCIAL STATEMENTS

              Not applicable.

SECTION 5.    CORPORATE GOVERNANCE AND MANAGEMENT

              Not applicable.

SECTION 6.    ASSET-BACKED SECURITIES

              Not Applicable.

SECTION 7.    REGULATION FD

              Not applicable.

SECTION 8.    OTHER EVENTS

     ITEM 8.01   OTHER EVENTS

                 99.1  Distribution to holders of the PreferredPLUS Trust
                       Certificates Series QWS-1 on August 15, 2006.

                             For information with respect to the underlying
                       securities held by PreferredPLUS Trust Series QWS-1,
                       please refer to Qwest Communications International Inc.'s
                       (Commission file number 001-15577) periodic reports,
                       including annual reports on Form 10-K, quarterly reports
                       on Form 10-Q and current reports on Form 8-K, and other
                       information on file with the Securities and Exchange
                       Commission (the "SEC"). You can read and copy these
                       reports and other information at the public reference
                       facilities maintained by the SEC at Room 1580, 100 F
                       Street, NE, Washington, D.C. 20549. You may obtain copies
                       of this material for a fee by writing to the SEC's Public
                       Reference Section of the SEC at 100 F Street, NE,
                       Washington, D.C. 20549. You may obtain information about
                       the operation of the Public Reference Room by calling the
                       SEC at 1-800-SEC-0330. You can also access some of this
                       information electronically by means of the SEC's website
                       on the Internet at http://www.sec.gov, which contains
                       reports, proxy and information statements and other
                       information that the underlying securities guarantor and
                       the underlying securities issuer has filed electronically
                       with the SEC.


<PAGE>

                             Although we have no reason to believe the
                       information concerning the underlying securities and the
                       guarantee or the underlying securities issuer and the
                       underlying securities guarantor contained in the
                       underlying securities guarantor's Exchange Act reports is
                       not reliable, neither the depositor nor the trustee
                       participated in the preparation of such documents or made
                       any due diligence inquiry with respect to the information
                       provided therein. No investigation with respect to the
                       underlying securities issuer and the underlying
                       securities guarantor (including, without limitation, no
                       investigation as to their respective financial condition
                       or creditworthiness) or of the underlying securities and
                       the guarantee has been made. You should obtain and
                       evaluate the same information concerning the underlying
                       securities issuer and the underlying securities guarantor
                       as you would obtain and evaluate if you were investing
                       directly in the underlying securities or in other
                       securities issued by the underlying securities issuer or
                       the underlying securities guarantor. There can be no
                       assurance that events affecting the underlying securities
                       and the guarantee or the underlying securities issuer and
                       the underlying securities guarantor have not occurred or
                       have not yet been publicly disclosed which would affect
                       the accuracy or completeness of the publicly available
                       documents described above.


SECTION 9.   FINANCIAL STATEMENTS AND EXHIBITS

     ITEM 9.01   FINANCIAL STATEMENTS AND EXHIBITS

           (a)   Financial statements of business acquired.

                 Not Applicable.

           (b)   Pro forma financial information.

                 Not Applicable.

           (c)   Shell company transactions.

                 Not Applicable.

           (d)   Exhibits.

                 99.1     Trustee's report in respect of the August 15, 2006
                          distribution to holders of the PreferredPLUS Trust
                          Certificates Series QWS-1.


<PAGE>

                                   SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned, hereunto duly authorized.


                                            MERRILL LYNCH DEPOSITOR, INC.

Date: 08/25/2006                            By:    /s/ Jason Liddell
                                                   -----------------------------
                                            Name:  Jason Liddell
                                            Title: Vice-President


<PAGE>

                                  EXHIBIT INDEX


99.1     Trustee's report in respect of the August 15, 2006 distribution to
         holders of the PreferredPLUS Trust Certificates Series QWS-1.
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SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D. C. 20549
                           --------------------------

                                    FORM 8-K

                                 CURRENT REPORT

                       Pursuant to Section 13 or 15(d) of
                       The Securities Exchange Act of 1934
                            -------------------------

        Date of Report (Date of earliest event reported): August 15, 2006

                          MERRILL LYNCH DEPOSITOR, INC.
                 (ON BEHALF OF PREFERREDPLUS TRUST SERIES QWS-1)
             (Exact name of registrant as specified in its charter)

            DELAWARE               001-16727                    13-3891329
        (State or other          (Commission                (I. R. S. Employer
        jurisdiction  of          File Number)              Identification No.)
         incorporation)

     WORLD FINANCIAL CENTER,                                       10080
       NEW YORK, NEW YORK                                       (Zip Code)
      (Address of principal
       executive offices)
                           --------------------------

       Registrant's telephone number, including area code: (212) 449-1000

                      INFORMATION TO BE INCLUDED IN REPORT

Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions (see General Instruction A.2.):

[  ]  Written communications pursuant to Rule 425 under the Securities Act (17
      CFR 230.425)

[  ]  Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17
      CFR 240.14a-12)

[  ]  Pre-commencement communications pursuant to Rule 14d-2(b) under the
      Exchange Act (17 CFR 240.14d-2(b))

[  ]  Pre-commencement communications pursuant to Rule 13e-4(c) under the
      Exchange Act (17 CFR 240.13e-4(c))
SECTION 1.    REGISTRANT'S BUSINESS AND OPERATIONS

              Not applicable.

SECTION 2.    FINANCIAL INFORMATION

              Not applicable.

SECTION 3.    SECURITIES AND TRADING MARKETS

              Not applicable.

SECTION 4.    MATTERS RELATED TO ACCOUNTANTS AND FINANCIAL STATEMENTS

              Not applicable.

SECTION 5.    CORPORATE GOVERNANCE AND MANAGEMENT

              Not applicable.

SECTION 6.    ASSET-BACKED SECURITIES

              Not Applicable.

SECTION 7.    REGULATION FD

              Not applicable.

SECTION 8.    OTHER EVENTS

     ITEM 8.01   OTHER EVENTS

                 99.1  Distribution to holders of the PreferredPLUS Trust
                       Certificates Series QWS-1 on August 15, 2006.

                             For information with respect to the underlying
                       securities held by PreferredPLUS Trust Series QWS-1,
                       please refer to Qwest Communications International Inc.'s
                       (Commission file number 001-15577) periodic reports,
                       including annual reports on Form 10-K, quarterly reports
                       on Form 10-Q and current reports on Form 8-K, and other
                       information on file with the Securities and Exchange
                       Commission (the "SEC"). You can read and copy these
                       reports and other information at the public reference
                       facilities maintained by the SEC at Room 1580, 100 F
                       Street, NE, Washington, D.C. 20549. You may obtain copies
                       of this material for a fee by writing to the SEC's Public
                       Reference Section of the SEC at 100 F Street, NE,
                       Washington, D.C. 20549. You may obtain information about
                       the operation of the Public Reference Room by calling the
                       SEC at 1-800-SEC-0330. You can also access some of this
                       information electronically by means of the SEC's website
                       on the Internet at http://www.sec.gov, which contains
                       reports, proxy and information statements and other
                       information that the underlying securities guarantor and
                       the underlying securities issuer has filed electronically
                       with the SEC.
Although we have no reason to believe the
                       information concerning the underlying securities and the
                       guarantee or the underlying securities issuer and the
                       underlying securities guarantor contained in the
                       underlying securities guarantor's Exchange Act reports is
                       not reliable, neither the depositor nor the trustee
                       participated in the preparation of such documents or made
                       any due diligence inquiry with respect to the information
                       provided therein. No investigation with respect to the
                       underlying securities issuer and the underlying
                       securities guarantor (including, without limitation, no
                       investigation as to their respective financial condition
                       or creditworthiness) or of the underlying securities and
                       the guarantee has been made. You should obtain and
                       evaluate the same information concerning the underlying
                       securities issuer and the underlying securities guarantor
                       as you would obtain and evaluate if you were investing
                       directly in the underlying securities or in other
                       securities issued by the underlying securities issuer or
                       the underlying securities guarantor. There can be no
                       assurance that events affecting the underlying securities
                       and the guarantee or the underlying securities issuer and
                       the underlying securities guarantor have not occurred or
                       have not yet been publicly disclosed which would affect
                       the accuracy or completeness of the publicly available
                       documents described above.

SECTION 9.   FINANCIAL STATEMENTS AND EXHIBITS

     ITEM 9.01   FINANCIAL STATEMENTS AND EXHIBITS

           (a)   Financial statements of business acquired.

                 Not Applicable.

           (b)   Pro forma financial information.

                 Not Applicable.

           (c)   Shell company transactions.

                 Not Applicable.

           (d)   Exhibits.

                 99.1     Trustee's report in respect of the August 15, 2006
                          distribution to holders of the PreferredPLUS Trust
                          Certificates Series QWS-1.
SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned, hereunto duly authorized.

                                            MERRILL LYNCH DEPOSITOR, INC.

Date: 08/25/2006                            By:    /s/ Jason Liddell
                                                   -----------------------------
                                            Name:  Jason Liddell
                                            Title: Vice-President
EXHIBIT INDEX

99.1     Trustee's report in respect of the August 15, 2006 distribution to
         holders of the PreferredPLUS Trust Certificates Series QWS-1.