“…For example, alterations in free-running circadian period have been described during chronic administration of several different classes of antidepressants (Wollnik, 1992;Klemfuss and Kripke, 1994;Rosenwasser and Wirz-Justice, 1997;Duncan et al, 1998), the anxiolytic benzodiazepine, diazepam (Subramanian and Subbaraj, 1996), the putative depressogenic agent, clonidine (Rosenwasser, 1996), and ethanol (Dwyer and Rosenwasser, 1998;Rosenwasser et al, 2005). Surprisingly, both lengthening and shortening of free-running period have been observed, even for a given agent, and these effects appear to be modulated by a variety of factors, including both lighting conditions and individual differences in baseline period (Rosenwasser, 1996;Rosenwasser et al, 2005).…”