A motor-adjustable steering column for a motor vehicle has an outer casing which is held by a support unit that is attachable to a vehicle body. An actuator unit is received in the outer casing to adjust in the longitudinal direction. A steering spindle is coaxially and rotatably mounted in a casing tube in the actuator unit. An adjustment drive and an energy absorbing installation are disposed between the outer casing and the actuator unit. The adjustment drive has a spindle mechanism with a threaded spindle which is rotatably drivable by an electric servomotor engaged in a spindle nut. The energy absorbing installation has at least one energy absorbing element at least indirectly disposed between the spindle nut and the actuator unit. The spindle nut or the threaded spindle has at least one forming element which operatively engages with the energy absorbing element and is plastically deformable.