Trouble Falling Asleep: Why It Does Not Work and What Helps You Fall Asleep Fast
You are tired, but the moment you lie down, your mind is wide awake. Falling asleep rarely fails because of too little tiredness, but because of a system that is too awake. What lies behind it, why late coffee, screen light and rumination slow falling asleep, and which levers really help.
People with trouble falling asleep often come with the assumption that they lack tiredness. The opposite is usually the case: the sleep pressure is there, but the wake-maintaining system cannot be shut down. Riemann 2009 in Sleep Medicine Reviews calls this hyperarousal, a measurably elevated overarousal from autonomic to hormonal to electrophysiological. Three everyday factors additionally fuel this system: caffeine, which according to Drake 2013 in Journal of Clinical Sleep Medicine still reduces sleep duration 6 hours before bed, evening screen light, which according to Chang 2015 in PNAS suppresses melatonin and shifts the internal clock, and rumination, which maintains sleep effort. The good news: each of these adjustment screws can be turned, and core temperature is, according to Raymann 2005 and Haghayegh 2019, a surprisingly effective lever. Falling asleep cannot be forced, but you can create the conditions under which it happens by itself.
This spoke is the sleep-onset workshop of the sleep cluster. We first clarify why tiredness and the ability to fall asleep are two different things (hyperarousal), then go through the four big disruptive factors in the evening (caffeine, light, core temperature, rumination), look at the KPNI lenses on them, sort out what does not work, and close with three concrete levers and a placement of the pharmacological and behavioral therapy options.
Why tiredness is not the same as the ability to fall asleep
Sleep arises from the interplay of two systems: the sleep pressure that rises over the day, and the internal clock that sets the right window of time. Both can be right and yet falling asleep still does not work if a third system interferes: wakefulness itself. Falling asleep means that the arousal-maintaining network in the brain is shut down. If this network stays overactive, you lie tired but wide awake.
Insomnia as a state of chronic overarousal
Review Dieter Riemann and colleagues summarized the evidence on the hyperarousal model of primary insomnia in Sleep Medicine Reviews in 2009. The core idea: problems falling asleep and staying asleep can be understood as the end point of a chronic overarousal that can be measured on several levels. Autonomic (elevated heart rate and core body temperature), neuroendocrine (elevated cortisol and ACTH release), neuroimmunological and electrophysiological (faster EEG frequencies around sleep onset). According to the model, this overarousal results from the interplay of a genetic susceptibility, psychosocial burden and maintaining factors such as sleep-disturbing behavior, learned sleep-preventing associations and a tendency to ruminate and worry.
Riemann D, Spiegelhalder K, Feige B, et al. Sleep Med Rev. 2010;14(1):19-31. doi:10.1016/j.smrv.2009.04.002 · PMID: 19481481
This overarousal is not a character weakness, but partly inherited. A family study shows how closely susceptibility and overarousal are linked.
Heritable susceptibility and cognitive-emotional overarousal
Observational study Julio Fernandez-Mendoza and colleagues examined 135 nuclear families (270 parents and one adult child each) in the Journal of Sleep Research in 2014. They estimated the heritability of stress-related insomnia susceptibility at 29 percent. Parents with high susceptibility had three- to sevenfold increased odds of also having highly susceptible children, and these children showed more arousability, more cognitive overarousal before sleep and a more emotion-oriented coping style. The message for practice: those prone to overarousal fall asleep poorly more quickly under stress, and it is precisely these maintaining patterns that treatment addresses.
Fernandez-Mendoza J, Shaffer ML, Olavarrieta-Bernardino S, et al. J Sleep Res. 2014;23(5):489-98. doi:10.1111/jsr.12168 · PMID: 24889269
The decisive question with trouble falling asleep is not "how do I get more tired?", but "how does my system get calmer?". Generating more tiredness (a long afternoon nap, going to bed very early) often makes falling asleep worse. Dampening the overarousal improves it. This is exactly what the next sections are about.
Disruptive factor 1: caffeine, longer than you think
Caffeine blocks the docking sites for adenosine, the messenger that builds up sleep pressure over the day. As a result you feel more awake, even though the sleep pressure is physiologically there. The catch: caffeine stays active for a long time. The half-life is about 5 to 6 hours, which means that about half of an espresso at 4 p.m. is still in the blood at 10 p.m. In slow metabolizers (a common variant of the CYP1A2 gene) this stretches out considerably longer.
Caffeine 6 hours before bed measurably reduces sleep time
RCT Christopher Drake and colleagues tested the effect of a fixed caffeine dose (400 milligrams) at three time points in a double-blind, placebo-controlled manner in the Journal of Clinical Sleep Medicine in 2013: directly before bed, 3 hours and 6 hours before bedtime. All three time points disturbed sleep significantly compared with placebo (p less than 0.05 in each case), measured both by self-report and objectively with a validated wearable sleep monitor. Notably: even taking it 6 hours before bedtime clearly shortened total sleep time. The authors interpret this as empirical support for the recommendation to avoid relevant amounts of caffeine for at least 6 hours before bedtime.
Drake C, Roehrs T, Shambroom J, Roth T. J Clin Sleep Med. 2013;9(11):1195-200. doi:10.5664/jcsm.3170 · PMID: 24235903
In practice this means: the last caffeinated cup by early afternoon at the latest, in sensitive people even earlier. And caffeine hides in more places than just coffee: black and green tea, cola, energy drinks, mate, pre-workout powder and dark chocolate count too. Anyone who wants a warming drink in the evening is better off reaching for caffeine-free herbal teas.
Disruptive factor 2: light and screens in the evening
The internal clock orients itself above all on light. Short-wavelength, blue-enriched light in the evening falsely signals "still daytime" to the brain, suppresses melatonin release and shifts the sleep window later. This is exactly the light that smartphones, tablets and televisions emit.
Reading on a light-emitting device lengthens sleep onset latency
Clinical study Anne-Marie Chang and colleagues compared evening reading on a light-emitting e-book device with reading a printed book in the Proceedings of the National Academy of Sciences in 2015. Those who read on the light-emitting device took longer to fall asleep, were less sleepy in the evening, released less melatonin, shifted their internal clock later and were less alert the next morning. The experiment thereby shows directly that evening device light pushes the internal clock later and acutely dampens melatonin release.
Chang AM, Aeschbach D, Duffy JF, Czeisler CA. Proc Natl Acad Sci U S A. 2015;112(4):1232-7. doi:10.1073/pnas.1418490112 · PMID: 25535358
But it is not only about the light. Content such as news, work emails, social media or gripping series keeps the arousal system busy exactly when it should be shutting down. The two together, bright light and stirring content, are the most effective brake on falling asleep that most of us set for ourselves every day. More on the topic of light and circadian rhythm is in Spoke 18.
Disruptive factor 3: core temperature as a sleep signal
Here lies one of the most underestimated and at the same time most usable levers. The body initiates sleep through a drop in core temperature. This drop succeeds when blood flow to the skin of the hands and feet increases and heat is released to the outside. Cold feet in bed or a bedroom that is too warm impede this process.
Slight skin warming shortens sleep onset latency
Clinical study Roy Raymann, Dick Swaab and Eus Van Someren controlled the core and skin temperature of eight healthy people under controlled conditions in the American Journal of Physiology in 2005 and measured 144 sleep onset latencies. A warming of the proximal (trunk-near) skin regions by only about 0.8 degrees shortened sleep onset latency by around 26 percent, which corresponds to about 3 minutes shorter around a mean of just under 12 minutes. The study was the first to show a causal contribution of skin temperature to falling asleep within the normal nightly range of fluctuation. A complementary work by the group (Fronczek 2008 in Sleep) confirmed that core and skin temperature causally influence wakefulness and sleepiness.
Raymann RJEM, Swaab DF, Van Someren EJW. Am J Physiol Regul Integr Comp Physiol. 2005;288(6):R1589-97. doi:10.1152/ajpregu.00492.2004 · PMID: 15677527
A warm bath 1 to 2 hours before bed shortens falling asleep
Meta-analysis Shahab Haghayegh and colleagues summarized 17 works on passive body heating through a warm bath or warm shower in Sleep Medicine Reviews in 2019, 13 of them with comparable data for the meta-analysis. A bath or shower of 40 to 42.5 degrees, planned 1 to 2 hours before bedtime and for only about 10 minutes, significantly shortened sleep onset latency and improved sleep efficiency and subjective sleep quality. The mechanism sounds contradictory at first: the warmth draws the blood into the hands and feet, thereby promotes heat release and subsequently accelerates the drop in core temperature, exactly the signal that initiates sleep.
Haghayegh S, Khoshnevis S, Smolensky MH, Diller KR, Castriotta RJ. Sleep Med Rev. 2019;46:124-135. doi:10.1016/j.smrv.2019.04.008 · PMID: 31102877
Concretely this means: a warm bath or warm shower in the early evening, warm socks for cold feet, and a cool bedroom of about 18 degrees. This gives the body the temperature signal it needs for sleep onset.
Disruptive factor 4: rumination and sleep effort
As soon as falling asleep becomes difficult once, a vicious circle arises: you lie awake, think about the lost sleep, calculate how few hours are left, and try all the harder to fall asleep. This very effort is the problem. In sleep medicine it is called sleep effort: the active attempt to force sleep increases tension and thereby arousal, exactly what prevents sleep. Falling asleep is a passive process that cannot be forced.
Riemann 2009 explicitly places rumination and sleep-related worry as maintaining factors within the hyperarousal model. A classic antidote from behavioral therapy is paradoxical intention: you lie down with the calm intention to simply stay relaxed and awake and precisely not to actively fall asleep. This removes the performance pressure, and the system is allowed to shut down by itself. Kierlin 2008 in Journal of Psychiatric Practice lists paradoxical intention alongside stimulus control, sleep restriction and relaxation as an evidence-based non-pharmacological technique.
"I just have to try really hard to fall asleep." That is the most reliable way to stay awake. Sleep cannot be produced by willpower, only by removing the obstacles. Anyone still awake after about 20 minutes should get up, go to another, dimly lit room and do something quiet until genuine tiredness comes. The bed thus stays linked with sleep and not with lying awake and frustration (stimulus control).
The KPNI lenses on falling asleep
In Clinical Psychoneuroimmunology we view falling asleep not in isolation, but as the result of several interlocking systems. Four lenses help to sort out the individual causes.
Lens 1: Stress axis
A still high cortisol and sympathetic tone in the evening keeps the system awake. Riemann 2009 describes elevated neuroendocrine activity as part of the hyperarousal. Daily structure, reducing stimulation in the evening and breathing or relaxation routines can lower the tone.
Lens 2: Circadian control
Light is the strongest zeitgeber. Evening screen light shifts the internal clock later according to Chang 2015. Morning daylight and dimmed light in the evening stabilize the sleep window, see Spoke 18.
Lens 3: Thermoregulation
Sleep follows the drop in core temperature. Raymann 2005 and Haghayegh 2019 show that targeted heat release through the skin may shorten sleep onset latency. A warm bath in the early evening, a cool bedroom, warm feet.
Lens 4: Cognition and behavior
Rumination, sleep effort and learned wake associations in bed maintain the overarousal. This is exactly where stimulus control, paradoxical intention and the building blocks of CBT-I come in (Furukawa 2024).
What does not work
Before we get to the levers, an honest look at widespread but unhelpful strategies.
- Drinking yourself tired. Alcohol often does shorten the time to falling asleep, but destroys the sleep architecture in the second half of the night and leads to early waking. Not a sleep aid.
- Going to bed earlier to gather more sleep. Anyone who goes to bed without sufficient sleep pressure only lies awake longer and couples the bed with being awake. This makes falling asleep worse.
- Sleep hygiene tips alone. Furukawa 2024 in JAMA Psychiatry found that sleep hygiene education as a sole building block is of little effect. The active behavioral therapy components are what help.
- Watching the clock. Calculating the remaining sleep time increases the pressure and the arousal. Turn the clock around.
The point is not to sleep perfectly, but to make falling asleep easier for the body and then to let go. Individual bad nights are normal and no cause for worry. Only when the pattern persists is a structured approach worthwhile, and for that there are effective tools.
Three levers for the next night
Defuse the evening
Last relevant caffeine dose in the early afternoon (Drake 2013). In the last hour before bed, avoid bright screens or dim them strongly and leave out stirring content (Chang 2015). This removes two accelerants of overarousal.
Set the temperature signal
A warm bath or warm shower of 40 to 42.5 degrees for about 10 minutes, planned 1 to 2 hours before bedtime (Haghayegh 2019). Afterwards keep the bedroom cool and put on socks for cold feet. This supports the drop in core temperature.
Take out the pressure
Do not want to fall asleep, but allow yourself to lie relaxed and awake (paradoxical intention, Kierlin 2008). Anyone still awake after about 20 minutes gets up and only returns when genuine tiredness comes (stimulus control). The clock is turned around.
When the pattern persists: placing melatonin and CBT-I
With occasional trouble falling asleep, the levers above are usually enough. If the problem persists stubbornly, it is worth looking at two options with different evidence bases.
Melatonin may shorten sleep onset latency a little, but the effect is modest. Ferracioli-Oda 2013 in PLoS One showed in a meta-analysis of 19 studies with 1683 people an average shortening of sleep onset latency by about 7 minutes and a lengthening of total sleep time by about 8 minutes compared with placebo, with improved subjective sleep quality. Melatonin works mainly through the timing control of the internal clock, not as a sedative. It can therefore make sense when the time of falling asleep is shifted later. Dose and timing belong in medical hands.
CBT-I shortens sleep onset latency durably
Meta-analysis James Trauer and colleagues evaluated 20 randomized studies with 1162 people in the Annals of Internal Medicine in 2015. Cognitive behavioral therapy for insomnia (CBT-I) shortened sleep onset latency on average by about 19 minutes, reduced nighttime wake time by about 26 minutes and improved sleep efficiency by around 10 percentage points, with an effect lasting over time and without reported side effects. Furukawa 2024 in JAMA Psychiatry analyzed 241 studies with over 31000 people in a component network meta-analysis and identified cognitive restructuring, third-wave components, sleep restriction and stimulus control as the most effective building blocks, especially in the personal, therapist-led format.
Trauer JM, Qian MY, Doyle JS, et al. Ann Intern Med. 2015;163(3):191-204. doi:10.7326/M14-2841 · PMID: 26054060
CBT-I is, according to current evidence, the first-line treatment for chronic problems falling asleep and staying asleep and is covered in detail in Spoke 9. The levers from this spoke combine well with it.
Falling asleep is letting go, not trying hard
Anyone who defuses the evening, sets the temperature signal and takes out the pressure creates the conditions under which falling asleep happens by itself. The goal is not the perfect night, but a system that is allowed to shut down again.
Safety note
This text serves information and orientation and does not replace a medical examination. Individual bad nights are normal. If trouble falling asleep persists for more than three months on at least three nights per week and noticeably impairs your day, or if there are signs of another cause (loud snoring with breathing pauses, a pronounced urge to move the legs in the evening, marked anxiety or low mood, new complaints after starting a medication), the evaluation belongs in medical hands. A conversation is also sensible with regular use of sleeping pills. Do not start any dietary supplement and no medication for sleep promotion without medical consultation, especially not in pregnancy and breastfeeding or with existing conditions.
Frequently asked questions about trouble falling asleep
Why can't I fall asleep even though I am tired?
Because tiredness (sleep pressure) and the ability to fall asleep are two different things. Falling asleep requires that the wake-maintaining arousal system is shut down. If this system stays overactive, it is called hyperarousal. Riemann 2009 in Sleep Medicine Reviews summarizes the evidence: in insomnia, elevated arousal levels appear on many levels, from autonomic (heart rate, body temperature) to neuroendocrine (cortisol) to electrophysiological (faster EEG frequencies before falling asleep). The system is therefore too awake to let sleep pressure take effect. This is exactly why you feel exhausted during the day but wide awake in bed at night. Treatment does not start with more tiredness, but with dampening the overarousal: reducing stimulation in the evening, a consistent wake rhythm, cognitive distance from rumination and, where appropriate, structured cognitive behavioral therapy for insomnia (CBT-I).
How long before sleep should I stop drinking coffee?
At least 6 hours, in sensitive people rather 8 to 10 hours. Drake 2013 in Journal of Clinical Sleep Medicine gave 400 milligrams of caffeine at three time points in a double-blind, placebo-controlled study: directly before bed, 3 hours and 6 hours beforehand. All three time points disturbed sleep measurably compared with placebo, and even taking it 6 hours before bedtime clearly reduced objectively measured total sleep time. Caffeine has a half-life of about 5 to 6 hours, which means that after an espresso at 4 p.m. about half is still active at 10 p.m. In slow metabolizers (a common CYP1A2 gene variant) the effect lasts even longer. In practice: the last caffeinated cup by early afternoon at the latest, and black and green tea, cola, energy drinks as well as dark chocolate count too.
Do the phone or the television really disturb falling asleep?
Yes, in two ways. Chang 2015 in PNAS compared, in a controlled experiment, reading on a light-emitting device with reading a printed book before bedtime. The screen group took longer to fall asleep, released less melatonin, shifted their internal clock later and was less alert the next morning. The first way is therefore the short-wavelength, blue-enriched light that suppresses melatonin release and pushes the zeitgeber system later. The second way is the content: news, work, social media and games keep the arousal system active, exactly what should be shutting down when falling asleep. In practice both can help: avoid bright screens during the last hour or dim them strongly and use night mode, but above all reduce emotionally stirring content in the evening.
What does body temperature have to do with falling asleep?
A great deal. The body initiates sleep through a drop in core temperature, enabled by increased blood flow to the skin of the hands and feet, that is, heat release to the outside. Raymann 2005 in American Journal of Physiology showed experimentally: a slight warming of the proximal skin regions by only about 0.8 degrees shortened sleep onset latency by around 26 percent. Haghayegh 2019 summarized 13 comparable studies in Sleep Medicine Reviews: a warm bath or warm shower of 40 to 42.5 degrees, planned 1 to 2 hours before bedtime and for only about 10 minutes, significantly shortened sleep onset latency and improved sleep quality. The mechanism sounds paradoxical: the warmth draws the blood into the skin, thereby promotes heat release and accelerates the drop in core temperature after the bath. In practice: take a warm bath or shower in the early evening, keep hands and feet warm, keep the bedroom cool (about 18 degrees).
Why do I fall asleep worse the harder I try?
Because falling asleep is a passive process that active effort disturbs. In sleep medicine this is called sleep effort: the attempt to force sleep increases tension and thereby arousal, exactly what prevents sleep. Riemann 2009 places this mechanism within the hyperarousal model, together with rumination and sleep-related worry as maintaining factors. A classic behavioral therapy tool against it is paradoxical intention: you lie down with the calm intention to simply stay awake and not actively fall asleep. This removes the performance pressure and the system is allowed to shut down. Kierlin 2008 in Journal of Psychiatric Practice names paradoxical intention as one of the evidence-based non-pharmacological techniques. In addition: if you are still awake after about 20 minutes, get up, go to another, dimly lit room and only return when you feel genuine tiredness (stimulus control).
Does melatonin help with falling asleep?
It may shorten sleep onset latency a little, but the effect is modest. Ferracioli-Oda 2013 in PLoS One summarized 19 studies with 1683 people in a meta-analysis: melatonin shortened sleep onset latency on average by about 7 minutes and lengthened total sleep time by about 8 minutes compared with placebo, with improved subjective sleep quality. The authors emphasize that the absolute benefit is smaller than with classic sleeping pills, but the side-effect profile is favorable. Melatonin works mainly through timing (shifting the internal clock), not as a sedative. It can therefore make sense when the time of falling asleep is shifted later, for example in shift work or a delayed sleep phase type. A medical evaluation is sensible, because dose and timing are decisive and melatonin does not replace sleep hygiene and does not replace behavioral therapy.
What is the most effective treatment for persistent trouble falling asleep?
Cognitive behavioral therapy for insomnia (CBT-I) is, according to current evidence, the first-line treatment for chronic problems falling asleep and staying asleep. Trauer 2015 in Annals of Internal Medicine evaluated 20 studies with 1162 people in a meta-analysis: CBT-I shortened sleep onset latency on average by about 19 minutes and improved sleep efficiency by around 10 percentage points, with a lasting effect and without reported side effects. Furukawa 2024 in JAMA Psychiatry analyzed 241 studies with over 31000 people in a component network meta-analysis and identified as particularly effective building blocks cognitive restructuring, so-called third-wave components, sleep restriction and stimulus control. Sleep hygiene education alone was of little effect and relaxation methods were rather weak in this analysis. CBT-I is covered in detail in Spoke 9. This spoke provides the quick levers that combine well with CBT-I.
When does trouble falling asleep become a case for the doctor?
Individual bad nights are normal and not a treatment case. You should have trouble falling asleep evaluated medically if it persists for more than three months on at least three nights per week and noticeably impairs your day (exhaustion, concentration or mood problems), which corresponds to the definition of chronic insomnia. Likewise if there are signs of another cause: loud snoring with breathing pauses (suspected sleep apnea), uncomfortable urge to move the legs in the evening (restless legs syndrome), pronounced anxiety or depressive symptoms, or if trouble falling asleep appears after starting a medication. A medical evaluation is also sensible if you regularly reach for sleeping pills. This text provides orientation and does not replace a medical examination. With persistent distress, a personal conversation is the right next step.
More from the cluster "Treating sleep disorders holistically"
- Pillar: Sleep disorders holistically
- Spoke 2: Trouble falling asleep and falling asleep fast (you are here)
- Spoke 8: Sleep hygiene
- Spoke 9: CBT-I for insomnia
- Spoke 18: Light and circadian rhythm
Connections to other topics
The pillar places problems with falling asleep, staying asleep and rhythm in the larger context and guides through all building blocks of the cluster.
The everyday framework conditions for good sleep: fixed times, sleep environment, caffeine and alcohol. The basis on which the sleep-onset levers build.
The first-line treatment for chronic insomnia according to Trauer 2015 and Furukawa 2024. Stimulus control, sleep restriction and cognitive restructuring in detail.
Why light is the strongest zeitgeber and how morning daylight and dimmed evening light stabilize the sleep window (Chang 2015).
Sources and further reading
- Riemann D, Spiegelhalder K, Feige B, et al. The hyperarousal model of insomnia: a review of the concept and its evidence. Sleep Med Rev. 2010;14(1):19-31. doi:10.1016/j.smrv.2009.04.002 · PMID: 19481481 [Review]
- Fernandez-Mendoza J, Shaffer ML, Olavarrieta-Bernardino S, et al. Cognitive-emotional hyperarousal in the offspring of parents vulnerable to insomnia: a nuclear family study. J Sleep Res. 2014;23(5):489-98. doi:10.1111/jsr.12168 · PMID: 24889269 [Real-World]
- Drake C, Roehrs T, Shambroom J, Roth T. Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. J Clin Sleep Med. 2013;9(11):1195-200. doi:10.5664/jcsm.3170 · PMID: 24235903 [RCT]
- Chang AM, Aeschbach D, Duffy JF, Czeisler CA. Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proc Natl Acad Sci U S A. 2015;112(4):1232-7. doi:10.1073/pnas.1418490112 · PMID: 25535358 [RCT]
- Raymann RJEM, Swaab DF, Van Someren EJW. Cutaneous warming promotes sleep onset. Am J Physiol Regul Integr Comp Physiol. 2005;288(6):R1589-97. doi:10.1152/ajpregu.00492.2004 · PMID: 15677527 [RCT]
- Fronczek R, Raymann RJEM, Romeijn N, et al. Manipulation of core body and skin temperature improves vigilance and maintenance of wakefulness in narcolepsy. Sleep. 2008;31(2):233-40. doi:10.1093/sleep/31.2.233 · PMID: 18274271 [Pathophysiology]
- Haghayegh S, Khoshnevis S, Smolensky MH, Diller KR, Castriotta RJ. Before-bedtime passive body heating by warm shower or bath to improve sleep: A systematic review and meta-analysis. Sleep Med Rev. 2019;46:124-135. doi:10.1016/j.smrv.2019.04.008 · PMID: 31102877 [Meta-analysis]
- Kierlin L. Sleeping without a pill: nonpharmacologic treatments for insomnia. J Psychiatr Pract. 2008;14(6):403-7. doi:10.1097/01.pra.0000341896.73926.6c · PMID: 19057243 [Review]
- Ferracioli-Oda E, Qawasmi A, Bloch MH. Meta-analysis: melatonin for the treatment of primary sleep disorders. PLoS One. 2013;8(5):e63773. doi:10.1371/journal.pone.0063773 · PMID: 23691095 [Meta-analysis]
- Trauer JM, Qian MY, Doyle JS, Rajaratnam SMW, Cunnington D. Cognitive Behavioral Therapy for Chronic Insomnia: A Systematic Review and Meta-analysis. Ann Intern Med. 2015;163(3):191-204. doi:10.7326/M14-2841 · PMID: 26054060 [Meta-analysis]
- Furukawa Y, Sakata M, Yamamoto R, et al. Components and Delivery Formats of Cognitive Behavioral Therapy for Chronic Insomnia in Adults: A Systematic Review and Component Network Meta-Analysis. JAMA Psychiatry. 2024;81(4):357-365. doi:10.1001/jamapsychiatry.2023.5060 · PMID: 38231522 [Meta-analysis]