On 2014 Aug 27, Daniel Kripke commented:

Despite much useful material, the report of Owens and colleagues about insufficient sleep was marred by insufficient evidence-based definition of insufficient sleep. “Sufficient sleep” was “defined as ≥8 hours,” but why? Consider that in a Japanese nation-wide sample of adolescents grade 7 through 12, ≥7-<8 hours was associated with the best General Health in a number of grade groups of boys and girls and overall ≥8-<9 hours was not significantly superior in predicting mental health [1]. Consider that in a unique lifetime study of mortality risk, girls sleeping 2 hours less than the average for age 16 had the same mortality as those sleeping the average, whereas mortality was about the same for boys sleeping 1 hour less than the average [2]. More evidence concerning optimal sleep durations for adolescents is needed. Should we recognize that much of the evidence-absent advocacy for children to sleep more has been financed by hypnotics manufacturers, and has been accompanied by a sharp increase in hypnotic prescriptions for children? 1. Kaneita Y, et al. J Clin Psychiatry 2007;68:1426-1435. 2. Duggan KA, et al. Health Psychol 2014, in press.

On 2014 Aug 27, Daniel Kripke commented:

Despite much useful material, the report of Owens and colleagues about insufficient sleep was marred by insufficient evidence-based definition of insufficient sleep. “Sufficient sleep” was “defined as ≥8 hours,” but why? Consider that in a Japanese nation-wide sample of adolescents grade 7 through 12, ≥7-<8 hours was associated with the best General Health in a number of grade groups of boys and girls and overall ≥8-<9 hours was not significantly superior in predicting mental health [1]. Consider that in a unique lifetime study of mortality risk, girls sleeping 2 hours less than the average for age 16 had the same mortality as those sleeping the average, whereas mortality was about the same for boys sleeping 1 hour less than the average [2]. More evidence concerning optimal sleep durations for adolescents is needed. Should we recognize that much of the evidence-absent advocacy for children to sleep more has been financed by hypnotics manufacturers, and has been accompanied by a sharp increase in hypnotic prescriptions for children? 1. Kaneita Y, et al. J Clin Psychiatry 2007;68:1426-1435. 2. Duggan KA, et al. Health Psychol 2014, in press.