Modern society, with the invention of artificial light, has achieved apparent independence from the solar day, but at what cost? Chronobiologists consider our 24/7 lifestyle and lack of clear light-dark ABT 888 exposure to be the downside of temporal freedom, and that it contributes to the increasing

Inhibitors,research,lifescience,medical incidence of depressive and sleep disorders. The only way of countering a lack of temporal order is to reestablish regular synchronizing signals, the most prominent of these being light. A great deal of research shows how the timing, intensity, and spectral composition of light affects human behavior separately from vision, providing not only a new treatment, but in addition, Inhibitors,research,lifescience,medical a conceptual development in architectural lighting. The more we know about the importance of light (in particular blue wavelengths) for these “nonvisual” photic fonctions related to the biological clock, the more we can apply it to general and mental health. An exciting fast-moving field incorporates this aspect in the design of buildings with optimum daylight exposure and adequate artifical Inhibitors,research,lifescience,medical light, ranging from work and school environments to retirement homes or neonatal units and emergency rooms in hospitals. What

does this mean for everyday clinical work? First, the long-established backbone of psychiatric practice has been to develop and maintain regular patterns of sleep, mealtimes, Inhibitors,research,lifescience,medical work, and exercise in patients in order to structure the day. This can be interpreted in chronobiological terms as increasing the strength of different zeitgebers to enhance good synchronization Inhibitors,research,lifescience,medical of rhythms. Indeed, “social zeitgeber” therapy has been developed on these principles and successfully applied. Second, more attention should be paid to the environment in which patients spend their days. If

the ward or rooms are poorly lit, with small windows and facing West or North, the amount of “biologically active” no light will be too little for improving mood, cognition, and sleep. For example, depressed patients who lived on the sunny East side of a ward stayed 3 days less in hospital than those in dim room without morning light; in a prospective study, depressed patients also stayed 3 days less in hospital after lighting in bedroom, dining area, corridors and dayroom was augmented, than before the renovation. This indicates, as do investigations of the effect of light on many psychological and behavioral indices in healthy subjects, that good environmental lighting acts as a passive adjunct therapy.