<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, 2005

                          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


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.  [RESERVED]

SECTION 7.  REGULATION FD

            Not applicable.

SECTION 8.  OTHER EVENTS


<PAGE>

         ITEM 8.01 OTHER EVENTS

                  99.1  Distribution to holders of the PreferredPLUS Trust
                        Certificates Series QWS-1 on August 15, 2005.

                              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.

<PAGE>

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)  Exhibits.

                              99.1 Trustee's report in respect of the August 15,
                        2005 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: 08/25/05                     By: /s/ Stephan Kuppenheimer
                                                ------------------------------
                                            Name: Stephan Kuppenheimer
                                            Title: President



<PAGE>



                                  EXHIBIT INDEX


      99.1  Trustee's report in respect of the August 15, 2005 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, 2005

                          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

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.  [RESERVED]

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, 2005.

                              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)  Exhibits.

                              99.1 Trustee's report in respect of the August 15,
                        2005 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: 08/25/05                     By: /s/ Stephan Kuppenheimer
                                                ------------------------------
                                            Name: Stephan Kuppenheimer
                                            Title: President
EXHIBIT INDEX

      99.1  Trustee's report in respect of the August 15, 2005 distribution to
            holders of the PreferredPLUS Trust Certificates Series QWS-1.