Endpoint

Total sleep time

Total number of hours of sleep in a day.

Definition from MeSH (D000094362), National Library of Medicine, read 2026-09-23. NLM revises MeSH; this copy may not reflect its current record.

CAT:outcome/total-sleep-timereported in minutes9 findings from 3 compounds

Open in the graph

What moved it

How to read these marks

9 findings · 3 compounds · 3 null · by evidence strength

Compound	Direction	Findings	Strongest evidence
zolpidem	up	1	Evidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.
melatonin	no effect 3 · up 3	6	Evidence strength: limited. Human evidence with several recorded weaknesses, or a design that tops out at limited.
caffeine	down	2	Evidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.

Reported to move it

6 findings

zolpidem — increases
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.Finding
“Meta-analysis of data from 4 studies showed that zolpidem increased total sleep time compared to placebo or no drug (MD: 0.78, 95% CI: 0.19–1.37, P =.009, I2 = 38%; Fig. 4).”
Quoted verbatim from The effect of zolpidem on sleep efficiency and obstructive sleep apnea severity in OSA patients: A systematic review and meta‑analysis..
Study

meta-analysis
Dose

10 mg, 1 to 14 days
Population

Adults with obstructive sleep apnea (AHI > 5 to > 30 events/h) in 4 pooled controlled trials of zolpidem 10 mg versus placebo or no drug; one pooled trial had all participants on CPAP, one gave atomoxetine-oxybutynin in both arms
Effect 0.78 mean difference, 95% CI 0.19 to 1.37
The effect of zolpidem on sleep efficiency and obstructive sleep apnea severity in OSA patients: A systematic review and meta‑analysis.2026PMID:42410839Permalink
caffeine — decreases
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.Findingreplicated ×1
“Random-effects meta-analysis showed that caffeine significantly reduced total sleep time (mean difference [MD] = -34.67 min), sleep efficiency (MD = -4.74 %), and slow-wave sleep proportions (SWS%) (MD = -1.01 %), while prolonging sleep onset latency (MD = +8.35 min).”
Quoted verbatim from Age- and dose-specific effects of caffeine on sleep: A meta-analysis of controlled crossover trials..
Study

meta-analysis
Population

Healthy adults; acute caffeine versus placebo, nighttime polysomnography. Overall pooled estimate across 22 controlled crossover trials, not an age or dose subgroup. Instrument: polysomnography.
Age- and dose-specific effects of caffeine on sleep: A meta-analysis of controlled crossover trials.2025PMID:41124973Permalink
melatonin — increases
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.Findingreplicated ×2
“Total time asleep increased with melatonin (19.8 +/- 61.9 minutes) as compared to placebo (-13.6 +/- 50.6 minutes; p = .01).”
Quoted verbatim from Effect of melatonin on sleep, behavior, and cognition in ADHD and chronic sleep-onset insomnia..
Study

RCT
Duration

4 weeks
Dose

3 or 6 mg melatonin (depending on body weight), or placebo, for 4 weeks
Population

children aged 6-12 years, medication-free, with ADHD and chronic sleep onset insomnia
Effect of melatonin on sleep, behavior, and cognition in ADHD and chronic sleep-onset insomnia.2007PMID:17242627Permalink
melatonin — increases
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.Findingreplicated ×2
“There was a statistically significant increase in diary-reported total sleep time (TST), which was the most commonly reported outcome for melatonin compared with placebo [pooled mean difference 29.6 minutes, 95% confidence interval (CI) 6.9 to 52.4 minutes; p = 0.01]; however, statistical heterogeneity was extremely high (97%).”
Quoted verbatim from Pharmacological and non-pharmacological interventions for non-respiratory sleep disturbance in children with neurodisabilities: a systematic review..
Study

meta-analysis
Population

children with neurodisabilities and non-respiratory sleep disturbance; pooled across a subset of 13 melatonin RCTs, TST reported by diary
Effect 29.6 mean difference, 95% CI 6.9 to 52.4
Pharmacological and non-pharmacological interventions for non-respiratory sleep disturbance in children with neurodisabilities: a systematic review.2018PMID:30382936Permalink
melatonin — increases
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.Findingreplicated ×2
“A meta-analysis of nine studies (n=541) showed that melatonin significantly improved total sleep time compared with placebo (mean difference (MD)=48.26 min, 95% CI 36.78 to 59.73, I2=31%).”
Quoted verbatim from Melatonin for the management of sleep problems in children with neurodevelopmental disorders: a systematic review and meta-analysis..
Study

meta-analysis
Participants

541
Population

Children under 18 years with neurodevelopmental disorders enrolled in randomised controlled trials of melatonin versus placebo or other intervention for sleep problems (13 RCTs, n=682 total)
Effect 48.26 mean difference, 95% CI 36.78 to 59.73
Melatonin for the management of sleep problems in children with neurodevelopmental disorders: a systematic review and meta-analysis.2018PMID:29720494Permalink
caffeine — decreases
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.Findingreplicated ×1
“Caffeine consumption reduced total sleep time by 45 min and sleep efficiency by 7%, with an increase in sleep onset latency of 9 min and wake after sleep onset of 12 min.”
Quoted verbatim from The effect of caffeine on subsequent sleep: A systematic review and meta-analysis..
Study

meta-analysis
Population

meta-analysis of 24 studies on the effect of caffeine consumption on subsequent night-time sleep
The effect of caffeine on subsequent sleep: A systematic review and meta-analysis.2023PMID:36870101Permalink

Measured, no effect detected

3 findings

melatonin — no detected effect on
LimitedEvidence strength: limited. Human evidence with several recorded weaknesses, or a design that tops out at limited.FindingNull resultreplicated ×2
“The median in-hospital sleep duration was 6.0 hours (IQR: 5.0–6.2), with slightly longer duration in the melatonin group (6.0 (5.3–6.3) vs 5.8 (5.0–6.0), p=0.136), though this difference was not statistically significant.”
Quoted verbatim from Effect of melatonin versus placebo for the prevention of delirium among medically hospitalised older patients: a double-blinded randomised controlled trial (project RESTORE)..
Study

RCT
Duration

5 days
Dose

5 mg or 8 mg oral melatonin nightly for up to 5 days (arms pooled)
Population

medically hospitalised patients aged 65 years and over; secondary endpoint, ITT; sleep duration from patient report and nursing observation, not polysomnography
Effect of melatonin versus placebo for the prevention of delirium among medically hospitalised older patients: a double-blinded randomised controlled trial (project RESTORE).2026PMID:41592826Permalink
melatonin — no detected effect on
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.FindingNull resultreplicated ×2
“Total Sleep Time (SECONDARY, minutes) -- NCT01114373: Melatonin 415.8 +/-10.9 (n=36) vs Placebo 413.4 +/-10.6 (n=36); difference 2.4; p=0.39, no significant difference”
Quoted verbatim from Melatonin and Nighttime Blood Pressure in African Americans--24 mg Study.
Study

crossover
Participants

72
Population

Hypertension; 18 Years+
Effect 2.4 mean difference
Melatonin and Nighttime Blood Pressure in African Americans--24 mg Study2015NCT01114373Permalink
melatonin — no detected effect on
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.FindingNull resultreplicated ×2
“Total Sleep Time (SECONDARY, minutes) -- NCT01114360: Melatonin 399.8 +/-11.0 (n=36) vs Placebo 412.2 +/-11.1 (n=36); difference -12.4; p=0.52, no significant difference”
Quoted verbatim from Melatonin and Nighttime Blood Pressure in African Americans-8 mg Study.
Study

crossover
Participants

72
Population

Hypertension; 18 Years+
Effect -12.4 mean difference
Melatonin and Nighttime Blood Pressure in African Americans-8 mg Study2015NCT01114360Permalink

How it is measured

Total time scored as sleep across a recording period, by polysomnography, actigraphy or sleep diary, with the instrument recorded with each finding.

Measured, not recorded

Subject: total sleep time
Measurements: 10 measurements
Recorded as a finding: No

Show what was measured

total sleep time
no effect, no evidence that melatonin altered total sleep time (as compared with baseline total sleep time), but there was a significant decrease in total sleep time while patients were taking placebo, n = 20
There was no evidence that melatonin altered total sleep time (as compared with baseline total sleep time), but there was a significant decrease in total sleep time while patients were taking placebo.
PMID:11211063 · one of two readings recorded this
Total sleep time
decreases
Caffeine typically prolonged sleep latency, reduced total sleep time and sleep efficiency, and worsened perceived sleep quality.
PMID:26899133 · one of two readings recorded this
total sleep time
increases
sleep efficiency, total sleep time, and sleep maintenance were increased
PMID:37128727 · one of two readings recorded this
total sleep time
increases, p = 0.006, n = 64
Total sleep time (h) | 6.57 ± 1.27 | 6.97 ± 1.15 |.006
PMID:38764237 · one of two readings recorded this
Total sleep time
no effect, p = 0.065
total sleep time tended to be longer on vilo-trazo (22.3 [−1.4, 46.0] min, P=0.065) compared to viloxazine alone
PMID:40360261 · one of two readings recorded this
Total sleep time
increases
Conversely, intake of 3 mg/day was shown to be effective in improving total sleep time (TST)
PMID:40507048 · one of two readings recorded this
total sleep time
decreases
Random-effects meta-analysis showed that caffeine significantly reduced total sleep time (mean difference [MD] = -34.67 min), sleep efficiency (MD = -4.74 %), and slow-wave sleep proportions (SWS%) (MD = -1.01 %), while prolonging sleep onset latency (MD = +8.35 min)
PMID:41124973 · one of two readings recorded this
total sleep time
decreases
Both high- and low-dose caffeine reduced total sleep time and sleep efficiency, and increased sleep onset latency, while high-dose caffeine additionally reduced SWS%
PMID:41124973 · one of two readings recorded this
total sleep time
decreases
Subgroup analyses showed that caffeine reduced total sleep time in both young and middle-aged groups
PMID:41124973 · one of two readings recorded this
total sleep time
increases, p = 0.009
Meta-analysis of data from 4 studies showed that zolpidem increased total sleep time compared to placebo or no drug (MD: 0.78, 95% CI: 0.19–1.37, P =.009, I2 = 38%; Fig. 4)
PMID:42410839 · one of two readings recorded this

Sources cited

9 papers

Subject: total sleep time
Findings: 9
Papers: 9

Compound

Direction

Findings

Strongest evidence

zolpidem

melatonin

no effect 3 · up 3

caffeine

down

Measured, not recorded

Subject

total sleep time

Measurements

10 measurements

Recorded as a finding

Show what was measured

total sleep time
no effect, no evidence that melatonin altered total sleep time (as compared with baseline total sleep time), but there was a significant decrease in total sleep time while patients were taking placebo, n = 20
There was no evidence that melatonin altered total sleep time (as compared with baseline total sleep time), but there was a significant decrease in total sleep time while patients were taking placebo.
PMID:11211063 · one of two readings recorded this
Total sleep time
decreases
Caffeine typically prolonged sleep latency, reduced total sleep time and sleep efficiency, and worsened perceived sleep quality.
PMID:26899133 · one of two readings recorded this
total sleep time
increases
sleep efficiency, total sleep time, and sleep maintenance were increased
PMID:37128727 · one of two readings recorded this
total sleep time
increases, p = 0.006, n = 64
Total sleep time (h) | 6.57 ± 1.27 | 6.97 ± 1.15 |.006
PMID:38764237 · one of two readings recorded this
Total sleep time
no effect, p = 0.065
total sleep time tended to be longer on vilo-trazo (22.3 [−1.4, 46.0] min, P=0.065) compared to viloxazine alone
PMID:40360261 · one of two readings recorded this
Total sleep time
increases
Conversely, intake of 3 mg/day was shown to be effective in improving total sleep time (TST)
PMID:40507048 · one of two readings recorded this
total sleep time
decreases
Random-effects meta-analysis showed that caffeine significantly reduced total sleep time (mean difference [MD] = -34.67 min), sleep efficiency (MD = -4.74 %), and slow-wave sleep proportions (SWS%) (MD = -1.01 %), while prolonging sleep onset latency (MD = +8.35 min)
PMID:41124973 · one of two readings recorded this
total sleep time
decreases
Both high- and low-dose caffeine reduced total sleep time and sleep efficiency, and increased sleep onset latency, while high-dose caffeine additionally reduced SWS%
PMID:41124973 · one of two readings recorded this
total sleep time
decreases
Subgroup analyses showed that caffeine reduced total sleep time in both young and middle-aged groups
PMID:41124973 · one of two readings recorded this
total sleep time
increases, p = 0.009
Meta-analysis of data from 4 studies showed that zolpidem increased total sleep time compared to placebo or no drug (MD: 0.78, 95% CI: 0.19–1.37, P =.009, I2 = 38%; Fig. 4)
PMID:42410839 · one of two readings recorded this