An adjustment drive for a steering column may include a drive unit having a threaded spindle that is supported in a gearbox housing at a bearing portion so as to be rotatable, with the threaded spindle including a threaded portion with a spindle thread that is axially adjoined to a shaft portion on which a gear wheel is arranged in a rotationally secure manner. The gear wheel meshes with a drive wheel that is coupled to a motor. Between the threaded portion and the gear wheel a peripheral bearing groove with a groove base may extend between groove flanks thereof. The bearing portion may be disposed in the bearing groove in a region of the groove base, and the bearing portion may be supported in a sliding manner in a bearing opening of a bearing plate that engages radially in the bearing groove.