[Maxima] "depends" problem of variables with subscripts

[Evan]

I'm using wxmaxima as the front-end of maxima

I use, for example, "x[1]" to produce a variable with subscripts
now I want to declare the dependence of "x[1]" on "t"
while "depends(x[1],t)" leads to an error as follows

The argument to depends must be a symbolic name:x[1] -- an error.  To
debug this try debugmode(true);


Should I use something else to denote subscripts?

p.s. how to produce a variable with superscripts?