It depends on the case; there is no single guideline.
Review: the need for sleep declines with age and varies between people due to genetics and other factors. General recommendations by age range are useful as a guide, but should be adjusted case by case. There is no single number valid for everyone.
View the study (study) →Lifestyle · Highest evidence: Low · 1 finding
Information, not medical advice. Prescription drugs require a doctor.
Information, not medical advice. Scientific evidence reflects the quality of the studies.