Melatonin treatment effects on adolescent students' sleep timing and sleepiness in a placebo-controlled crossover study.
Study Goal
The researchers aimed to determine whether a small afternoon dose of melatonin could advance sleep timing in teenagers with sleep-onset difficulties.
Results Summary
Melatonin significantly advanced sleep-onset times, increased sleep duration, reduced daytime sleepiness, and improved morning alertness compared to placebo. Evening melatonin levels increased and morning levels decreased, indicating a phase advance in circadian rhythm.
Population
21 students aged 14-19 years with sleep-onset difficulties during school weeks.
Effective Dosage
1 mg daily, administered between 16:30 and 18:00.
Duration
5 weeks (with melatonin administered during specific weeks).
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
melatonin (1 mg) capsules | decrease | reported sleep-onset times | students aged 14-19 yrs with sleep-onset difficulties | - | advanced | #1 |
melatonin (1 mg) capsules | increase | sleep length | students aged 14-19 yrs with sleep-onset difficulties | - | was longer | #2 |
melatonin (1 mg) capsules | decrease | sleep timing | students aged 14-19 yrs with sleep-onset difficulties | 68 min | fell asleep earlier | #3 |
melatonin (1 mg) capsules | increase | sleep duration | students aged 14-19 yrs with sleep-onset difficulties | 62 min | slept longer | #4 |
melatonin (1 mg) capsules | decrease | morning melatonin values in saliva | students aged 14-19 yrs with sleep-onset difficulties | - | diminished | #5 |
melatonin (1 mg) capsules | increase | evening melatonin values in saliva | students aged 14-19 yrs with sleep-onset difficulties | - | increased | #6 |
melatonin (1 mg) capsules | decrease | wake up | students aged 14-19 yrs with sleep-onset difficulties | - | less | #7 |
melatonin (1 mg) capsules | decrease | school daytime sleepiness | students aged 14-19 yrs with sleep-onset difficulties | - | less | #8 |
melatonin (1 mg) capsules | increase | evening sleepiness | students aged 14-19 yrs with sleep-onset difficulties | - | increased | #9 |
During the last few decades, the incidence of sleep-onset insomnia, due to delay of circadian phase, has increased substantially among adolescents all over the world. We wanted to investigate whether a small dose of melatonin given daily, administered in the afternoon, could advance the sleep timing in teenagers. Twenty-one students, aged 14-19 yrs, with sleep-onset difficulties during school weeks were recruited. The study was a randomized, double blind, placebo (PL)-controlled crossover trial, lasting 5 wks. During the first 6 d in wks 2 and 4, the students received either PL or melatonin (1 mg) capsules between 16:30 and 18:00 h. During the first 6 d of wk 5, all students received melatonin. Wks 1 and 3 were capsule-free. In the last evening of each week and the following morning, the students produced saliva samples at home for later melatonin analysis. The samples were produced the same time each week, as late as possible in the evening and as early as possible in the morning. Both the student and one parent received automatic mobile text messages 15 min before saliva sampling times and capsule intake at agreed times. Diaries with registration of presumed sleep, subjective sleepiness during the day (Karolinska Sleepiness Scale, KSS) and times for capsule intake and saliva samplings were completed each day. Primary analysis over 5 wks gave significant results for melatonin, sleep and KSS. Post hoc analysis showed that reported sleep-onset times were advanced after melatonin school weeks compared with PL school weeks (p < .005) and that sleep length was longer (p < .05). After the last melatonin school week, the students fell asleep 68 min earlier and slept 62 min longer each night compared with the baseline week. Morning melatonin values in saliva diminished compared with PL (p < .001) and evening values increased (p < .001), indicating a possible sleep phase advance. Compared with PL school weeks, the students reported less wake up (p < .05), less school daytime sleepiness (p < .05) and increased evening sleepiness (p < .005) during melatonin weeks. We conclude that a small dose of melatonin given daily, administered in the afternoon, could advance the sleep timing and make the students more alert during school days even if they continued their often irregular sleep habits during weekends.