EXHIBIT 3.93

                                     BYLAWS
                                       OF
                         BHC VALLE VISTA HOSPITAL, INC.

                  1.       Annual Meeting of the Shareholders. The annual
meeting of shareholders for the election of directors and such other purposes as
may be set forth in the notice of meeting shall be held at the time and place,
within or outside the State of Tennessee, fixed by the board of directors.

                  2.       Special Meetings of the Shareholders. Special
meetings of the shareholders may be held at any place within or outside the
State of Tennessee upon call of the board of directors, the chairman of the
board of directors, if any, the president, or the holders of at least ten
percent of the issued and outstanding shares of capital stock entitled to vote.

                  3.       Transfer of Stock. The capital stock of the
Corporation shall be transferred on the books of the Corporation by surrender of
properly endorsed certificates therefor by the holders thereof or their duly
authorized attorneys-in-fact. In case of transfer by attorney, the power of
attorney, duly executed and acknowledged, shall be deposited with the secretary.
The person in whose name stock stands on the books of the Corporation shall be
deemed by the Corporation to be the owner thereof for all purposes.

                  4.       Directors. The business of the Corporation shall be
managed by a board of directors consisting of not less than two nor more than
seven members, such number of directors within such range to be fixed by action
of the board of directors. The range of size for the board may be increased or
decreased by the shareholders. Vacancies in the board of directors, whether
resulting from an increase in the number of directors, the removal of directors
for or without cause, or otherwise, may be filled by a vote of a majority of the
directors then in office, although less than a quorum. Directors may be removed
for or without cause by the shareholders.

                  5.       Meetings of the Board of Directors. Regular meetings
of the board of directors may be held without notice of the date, time, place or
purpose of the meeting (a) at the location of the annual meeting of shareholders
immediately after the meeting in each year and (b) at such times and at such
places within or outside the State of Tennessee as shall be fixed by the board
of directors. Special meetings of the board of directors may be held at any
place within or outside the State of Tennessee upon call of the chairman of the
board of directors, if any, the president or a majority of the directors then in
office, which call shall set forth the date, time and place of meeting and, if
required by law, the purpose of the meeting. Written, oral, or any other mode of
notice of the date, tune and place of meeting shall be given for special
meetings in sufficient time, which need not exceed two days in advance, for the
convenient assembly of the directors. A majority of the number of directors of
the Corporation then in office, but in no event less than one-third of the
number of directors the Corporation would have if there were no vacancies in the
board of directors, shall constitute a quorum, and the vote of



a majority of the directors present at the time of the vote, if a quorum is
present, shall be the act of the board of directors.

                  6.       Officers. The board of directors shall elect a
president and secretary, and such other officers as it may deem appropriate. The
president, secretary, and any other officer so appointed by the board of
directors are authorized to execute certificates representing shares of the
Corporation's capital stock. Persons may hold more than one office except that
no person may serve as both president and secretary. Officers shall have the
authority and responsibilities given them by the board of directors, and each
officer shall hold office until his successor is elected and qualified, unless a
different term is specified by the board of directors.

                  7.       Committees. By resolution adopted by the greater of
(i) a majority of the directors of the Corporation then in office when the
action is taken or (ii) the number of directors required by the Charter or
bylaws to take action, the directors may designate from among their number one
or more directors to constitute an executive committee and other committees,
each of which, to the extent permitted by law, shall have the authority granted
it by the board of directors.

                  8.       Amendment of Bylaws. The bylaws of the Corporation
may be amended or repealed, and additional bylaws may be adopted, by action of
the board of directors or of the shareholders, but any bylaws adopted by the
shareholders may be amended or repealed only by the shareholders.

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