Elderly insomniacs are often treated pharmacologically with benzodiazepines, antihistamines, or natural products. A double-blind, randomized, crossover, placebo-controlled study was performed to assess the comparative pharmacodynamics of single doses of temazepam (15 and 30 mg), diphenhydramine (50 and 75 mg), and valerian (400 and 800 mg) in 14 healthy elderly volunteers (mean age, 71.6 years; range, 65–89). Assessments were made at 0, 0.5, 1, 2, 3, 4, 6, and 8 hours postdosing with use of validated measures of subjective sedation and mood (visual analogue scales, Tufts University Benzodiazepine scale) and psychomotor performance (manual tracking and digit symbol substitution tests). Temazepam had dose-dependent effects on sedation and psychomotor ability with a distinct time course. Temazepam 30 mg had the most detrimental effect on psychomotor ability (p < 0.001 compared with all other treatments). Temazepam 30 mg and both doses of diphenhydramine elicited significantly greater sedation than placebo (p < 0.05, all), and temazepam had the greatest effect. There was no difference in sedation scores between 50 and 75 mg diphenhydramine. Sedative effects were slightly lesser with 15 mg temazepam and were not significant in comparison with placebo. Psychomotor impairment was evident after administration of 75 mg diphenhydramine in comparison with placebo on the manual tracking test (p < 0.05); this was less than the impairment with 30 mg temazepam (p < 0.001) but similar to that with 15 mg temazepam (NS). No psychomotor impairment was detected with 50 mg diphenhydramine. Valerian was not different from placebo on any measure of psychomotor performance or sedation. Insomnia is a common condition with debilitating effects on health and quality of life and therefore has important clinical and societal implications. In an ambulatory adult population the prevalence of insomnia is estimated to range between 10% and 30%. 1 This estimate increases to 45%–66% in elderly community residents and may be as high as 66% in elderly residents of nursing homes. 2 Treatment for short-term acute episodes of insomnia in elderly individuals is usually pharmacological and includes prescription (most commonly benzodiazepines), over-the-counter (most commonly antihistamines), and herbal remedies. For some of these treatments, there is a lack of evidence of efficacy and/or usefulness. 3,4 Benzodiazepines such as temazepam are the most commonly prescribed sedative-hypnotic compounds because they are efficacious and relatively safe for use in younger and elderly populations. 5 The sedative and psychomotor effects of temazepam have been well documented in the elderly, and several clinical studies have demonstrated that 15-mg and 30-mg doses are effective. 6 The elderly often self-medicate with antihistamine medications such as diphenhydramine that can be purchased over the counter for sleep purposes. 7,8 Although some studies with elderly subjects report adequate sedation after diphenhydramine, 9–11 others have reported a lack of soporific effect. 12,13 These medications are not generally recommended for the treatment of acute insomnia in elderly individuals, partially because of ambiguity regarding their efficacy. 3,5,14 The roots and rhizomes of Valeriana officinalis have been used for centuries for their purported sedative properties. Elderly persons often self-medicate with herbal products such as valerian for the purposes of sleep. 15 Clinical studies that have been performed with valerian at doses of 400–900 mg indicate that it may have some effects on sleep latency and night awakenings, 16,17 quality of sleep, 17,18 and/or EEG spectra, with more time in deep sleep. 18,19 Clinical studies performed to assess the utility of valerian as a sedative-hypnotic are difficult to interpret because of small sample sizes, unknown composition of valerian, unconventional and qualitatively poor assessments, and/or failure to account for possible confounding factors in study design. 20 The objective of this study was to investigate the differential human pharmacology of single doses of these three sedative-hypnotic medications in an elderly population. This study compared temazepam (15 and 30 mg), diphenhydramine (50 and 75 mg), valerian (400 and 800 mg), and placebo in healthy elderly volunteers. Primary outcome measures were subjective sedation, psychomotor performance (objective sedation), and side effects.