In a randomised, double-blind, placebo-controlled, cross-over study for patients with insomnia it was found that valerian worked efficiently in targeting insomnia.  The study consisted of short and long-term effects of placebo and valerian targeting sleep disturbance. After a single dose of valerian, no effects on sleep structure and subjective sleep assessment were observed. After multiple-dose treatment, sleep efficiency showed a significant increase for both the placebo and the valerian.  It was recorded that treatment with a herbal extract of valerian had positive effects on sleep patterns and sleep perception of the insomnia patients, and can therefore be recommended for the treatment of patients with mild psychophysiological insomnia.