hi 88,
Really, over and under watering are the major causes for drooping.. Especially if the color of the leaves is a normal green, If the leaves or the stems are changing colr from green to yellow in conjunction with drooping, the first thing you will need to check is the pH.
You know, drooping can also be caused by a saturated medium (mudding soil) which is pretty much the same as over watering.
iloveyou