 Anesthetics and anesthesia are suspicious to induce dementia or aggravate preexistent cognitive deficits with or without evoking postoperative delirium. In animal trials various anesthetics induce increased levels of misfolded amyloid beta and protein tau, the molecular substance of pathophysiologic brain tissues of demented patients. The amount of those markers seems to correlate well with the degree of dementia 1. In contradiction, a single study indicates that the incidence of postoperative cognitive deficit POCD decreases if hypnotic depth is deep 2. Unfortunately the study did not sum up the amount of anesthetic drug load, since this would have clarified if the amount of anesthetics used is associated to POCD and dementia. Another possibility is that stress and noxious stimulation induced by light anesthesia results in POCD, whereas deep anesthesia protects from it or inhibits implicit memory. 