The present invention relates to a spindle drive having a first load path which is formed by the spindle and having a second load path which is formed by a torsion bar which is exposed to torsion, which is arranged in the spindle and is connected to it such that a rotary movement is exerted onto the spindle in at least one state of the threaded drive by the torsion bar, with the spindle drive having a sensor unit which is made such that it detects a relative movement between the spindle and the torsion bar.