This paper presents the optimality of decay estimate of solutions to the initial value problem of 1D Schrödinger equations containing a long-range dissipative nonlinearity, i.e.,
. Our aim is to obtain the two results. One asserts that, if the
-norm of a global solution, with an initial datum in the weighted Sobolev space, decays at the rate more rapid than
, then it must be a trivial solution. The other asserts that there exists a solution decaying just at the rate of
in
.