<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): February 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 February 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 February
                                    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: February 28, 2006               By:      /s/ Stephan Kuppenheimer
                                                         -----------------------
                                               Name:    Stephan Kuppenheimer
                                               Title:   President

<PAGE>

                                  EXHIBIT INDEX


                  99.1     Trustee's report in respect of the February 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): February 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 February 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 February
                                    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: February 28, 2006               By:      /s/ Stephan Kuppenheimer
                                                         -----------------------
                                               Name:    Stephan Kuppenheimer
                                               Title:   President
EXHIBIT INDEX

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