Numerous clinical trials in the 1960s and 1970s have attested to the anxiolytic efficacy of hydroxyzine and its beneficial effect on sleep, as well as in reducing stress and anxiety associated with coronary disease. Experience with hydroxyzine has also shown a lack of organ toxicity and an absence of dependency. Recent controlled clinical trials with hydroxyzine have confirmed its efficacy (at a fixed dose of 50 mg) in generalized anxiety disorder superiority over placebo on all anxiety measures from the first week with early target symptoms which are grouped in a cognitive component of anxiety. Efficacy was maintained throughout the 4 weeks of treatment and after abrupt discontinuation. In another controlled trial vs. lorazepam, hydroxyzine demonstrated greater and more rapid cognitive improvement.