Thus, it is of concern that a substantial percentage of ziprasidone-treated patients required benzodiazepines for the treatment of insomnia and that this percentage was not significantly lower than that for placebo-treated patients. Furthermore, the steady-state half-lives of these benzodiazepines and their metabolites are considerable: 14 hours for temazepam and 42 hours for diazepam (2). Using the general guideline that it takes about four half-lives for a drug to clear the body, these patients would have had clinically significant blood levels of these drugs during the day after evening administration. These levels could have affected several measures of efficacy and side effects. For example, they could have improved efficacy by reducing symptoms of mania or mood instability. And they could have caused side effects, for example, daytime sedation, which was a significant problem in the ziprasidone-treated group. Also, they could have reduced other potential side effects, including akathisia, acute dystonia, or parkinsonism. For these reasons, other studies will avoid sedative-hypnotics at bedtime or perhaps use a much shorter-acting agent, such as chloral hydrate.