What is the test for a defendant to be guilty of driving while under the influence of drugs in violation of Vehicle Code section 23152?

By contrast, for a defendant to be guilty of driving while under the influence of drugs in violation of Vehicle Code section 23152, subdivision (a), "`the . . . drug(s) must have so far affected the nervous system, the brain, or muscles [of the individual] as to impair to an appreciable degree the ability to operate a vehicle in a manner like that of an ordinarily prudent and cautious person in full possession of his faculties. [Citations.]'" (People v. Enriquez, supra, 42 Cal.App.4th at p. 665, 49 Cal.Rptr.2d 710 (italics in original); see also Gilbert v. Municipal Court, supra, 73 Cal.App.3d at p. 727, 140 Cal.Rptr. 897; Veh.Code, 312.) Driving while under the influence of drugs involves a greater impairment of an individual's faculties, and in that respect is not "similar" to being merely under the influence of drugs.