Zolpidem 'as needed': methodological issues and clinical findings.

This article introduces 'as needed' hypnotic treatment as a possible option in the psychopharmacological treatment for chronic but non-daily occurring insomnia complaints. This treatment option is a well-structured regimen designed by both patient and treating physician. It aims at providing symptomatic relief for sleepless nights and preventing the development of possible dependence on the hypnotic agent. A significant amount of responsibility regarding the necessary accompanying lifestyle changes remains in the patient's hands. This paper describes three of the early experiments designed as a 'proof of concept'. All three studies demonstrated that zolpidem can be used effectively and safely on a non-daily basis in individuals with chronic insomnia. Although these studies have methodological limitations, they opened doors to well-designed clinical trials in both in and outpatients. The scientific validation of this therapeutic approach is still in progress. In addition to sleep laboratory studies, ecological studies are needed to investigate pill-taking behaviour and the risk of dependence over a long period of time in real life settings.