Millions rely on cannabis as a nightly sleep aid, but a neurologist warns the relief is deceptive. THC helps people fall asleep faster while delivering less restorative rest, and quitting can trigger withdrawal that mimics the original problem. Here’s what actually works for insomnia instead.
The challenge is that tetrahydrocannabinol, the psychoactive ingredient in cannabis, does help people fall asleep faster — but it becomes less effective with regular use, so people need more to get the same result. In addition, falling asleep faster isn’t synonymous with sleeping well. Research has found that cannabis doesn’t consistently improve total sleep time or the restfulness of that sleep. Chronic users spend more time awake during the night and get less restorative sleep than non-users, even when they believe they’re sleeping better.
The real difficulty surfaces when chronic users try to stop. Withdrawal can bring back insomnia and disturbing dreams, alongside anxiety, depressed mood, irritability or appetite loss that can persist for weeks — luring users right back to cannabis without addressing what caused their sleep problems in the first place.
Fong-Isariyawongse is especially concerned about two groups: teens and military veterans with post-traumatic stress disorder. Brains are still under construction until our mid-20s, she explains, and regular cannabis use can interfere with healthy brain development. A 2021 imaging study of nearly 800 teenagers linked cannabis use to dose-dependent thinning of the prefrontal cortex, the region of the brain that governs judgment, decision-making and impulse control.
Moreover, veterans with PTSD who experience sleep disturbances at rates of 70% to 90% often turn to cannabis as a stop-gap while facing months-long waitlists for professional care with a Veteran’s Affairs medical centre. The trouble comes when care finally becomes available and some abruptly stop using cannabis, only to face withdrawal symptoms that closely mirror PTSD itself, including rebound insomnia, nightmares, worsening depression and in some cases suicidal thoughts. Mistaking withdrawal for relapse, many quickly return to cannabis and the cycle continues.
Credit: Annie Spratt/Unsplash
So what can people struggling with insomnia do instead? Fong-Isariyawongse’s primary recommendation is cognitive behavioural therapy for insomnia, or CBT-I. It’s research-backed and works by modifying sleep habits — resetting sleep-wake timing, lowering the body’s physical arousal and gently challenging anxious beliefs about sleeplessness. Veterans are often guided through image rehearsal therapy as part of CBT-I, rewriting the ending of a recurring nightmare and consciously replaying the new, peaceful version while awake. CBT-I is highly effective, more so than any sleep medication, including cannabis. But only trained providers can offer it, and with so few available many people who would benefit never get the opportunity.
In the meantime, experts say that a few smaller steps can help, including cutting back on screens before bed, getting checked for physical sleep disruptors like sleep apnoea or GERD, building a calming wind-down ritual, reserving the bedroom for sleep or sex only, exercising in the late afternoon and skipping caffeine, alcohol and nicotine before bed.
For millions of people, cannabis has become the unofficial prescription for lost sleep. But what feels like a solution may be quietly making the problem worse.
Consider these two cases:
She is 15 and has been lying in bed for the past hour. It is past midnight, and her brain will not quiet down. Her school bus comes at 6:20 a.m. She is getting anxious, knowing that she needs to wake up in six hours. She did all the right things: turned off her phone at 10 p.m., tried melatonin. So tonight she tries something a friend recommended: a cannabis gummy. Within 20 minutes, she’s asleep.
He is 34, a veteran who did two tours and has struggled with sleep since coming home. It takes him two hours to fall asleep, and when he does, he is jolted awake by relentless nightmares. He hasn’t slept more than three hours a night in months, and it’s catching up with him. His buddy swears that cannabis helped him, and with a six-month waiting list for a sleep consultation at the Veteran’s Affairs medical center and a cannabis dispensary six blocks away that’s open until 10 p.m., the decision doesn’t feel complicated.
Both will tell you cannabis works for their specific needs. They are not entirely wrong. But no one has told them what is actually happening inside the brain when the lights go out. It’s complex, and for them – as for many others – ultimately it’s a trap.
As a neurologist specializing in sleep and brain performance, I write this not as someone opposed to cannabis but as someone who regularly sees patients whose sleep has quietly unravelled after months or years of use, especially teenagers and veterans.
I believe the public deserves a more complete picture than they currently have due to the limited research that’s available.
A 2021 brain imaging study of 799 teenagers found that cannabis use was associated with dose-dependent thinning of the cerebral cortex – meaning the more cannabis a teenager used, the thinner their prefrontal cortex became. The prefrontal cortex is the region of the brain responsible for judgment, decision-making and impulse control. Thinning of the cortex in this region has been associated with increased impulsivity, poorer decision-making and reduced inhibitory control.
THC has a sedative effect at low doses but is stimulating at high doses. Cannabis also contains other cannabinoids – plant-derived compounds such as CBD and CBN that interact with a system in the body that produces its own cannabinoids and contributes to the sedative effects of cannabis.
In addition, falling asleep quicker is not the same as sleeping well. A 2025 review of the research to date found that cannabis does not consistently improve sleep overall, including how long people stay asleep or how restful that sleep is.
At this point many people are using cannabis not because it is working well, but because stopping feels worse.
Even when chronic cannabis users have the willpower to stop, they often face brutal withdrawal symptoms that are more severe than what drove them to cannabis in the first place. Sleep disturbance, including insomnia and disturbing dreams, is described as a common manifestation of cannabis withdrawal. In addition, two-thirds of users report other symptoms such as anxiety, depressed mood, restlessness, irritability, decreased appetite or a combination of these symptoms that often persist for weeks after stopping use.
This is the trap – it’s quiet and insidious, which makes it harder to see.
Cannabis works just enough to feel like a solution. Night after night it dulls the problem without fixing it, until stopping feels unthinkable. When someone finally tries to quit, their sleep falls apart. So they go back. The original reason they could not sleep has not been identified or treated, and it hasn’t gone away.
The developing brain is one kind of vulnerability. The traumatized brain is another.
Post-traumatic stress disorder affects an estimated 12% to 23% of post-9/11 veterans, compared with 6% to 8% of the general population. Sleep disturbances affect 70% to 90% of military personnel with PTSD. People with PTSD commonly have nightmares that are visceral, relentless and exhausting. They might be jolted awake with a pounding heart, multiple times a night, for years.
Because these withdrawal symptoms so closely mirror PTSD itself, many veterans interpret the return of symptoms as their condition worsening, not as withdrawal, so they go back to cannabis. And the cycle continues.
This therapy works by modifying sleep habits, regulating sleep-wake schedules, reducing arousal and reframing unhelpful beliefs about sleep. A form of treatment known as image rehearsal therapy, in which patients rewrite the storyline of a recurring nightmare and mentally rehearse the new version while awake, has been shown to be effective for veterans with trauma-related nightmares. But trained CBT-I providers are scarce, wait times are long, and most primary care settings do not offer it.
In other words, the people most vulnerable to the sleep-related harms of cannabis use are the least likely to have access to treatments that address the underlying problem, and the most likely to get caught in a negative cycle.
For those already caught in that cycle, quitting abruptly rarely works and often makes things worse. Research shows that CBT-I can reduce both insomnia and cannabis use at the same time – treating the root problem so cannabis no longer feels necessary.
Sleep is the foundation on which memory, mood, judgment and recovery are built.
The 15-year-old who cannot fall asleep and the veteran who wakes gasping at 3 a.m. both deserve evidence-based information about what is happening in their brains, and real access to care that treats the root cause.
Cannabis has become a common solution for sleep problems. Many users report that it “puts them to sleep” – but the medical picture regarding actual sleep quality is more complex
The natural temptation: Insomnia is one of the most common complaints in modern medicine. Against the backdrop of concern about addictive medications and side effects, cannabis is perceived by many as a more natural and safer alternative. Reports from the field are consistent – inhalation or drops before bedtime ease falling asleep and create a feeling of relaxation. However, when examining the picture through medical reports, it becomes clear that the question is not only how quickly one falls asleep, but what the sleep itself looks like.
Insomnia is one of the most common complaints in modern medicine (photo credit: SHUTTERSTOCK) Sleep physicians and neurologists describe in clinical reports that cannabis indeed shortens the time it takes to fall asleep, a phenomenon known as shortened sleep latency. This effect is mainly attributed to THC, the primary psychoactive substance in cannabis, which acts on receptors in the brain associated with calming and reducing arousal. For people who suffer from stress, anxiety, or difficulty “turning off the head,” this effect is clearly felt.
However, this is where the critical difference between falling asleep and quality sleep emerges. Normal sleep is built from sleep cycles that include different stages, foremost among them the REM stage – dream sleep, which is essential for emotional processing, memory, and mood regulation. Repeated medical reports indicate that regular cannabis use, particularly strains high in THC, reduces the duration of the REM stage. The meaning is lighter sleep, even if the total sleep duration does not shorten.
Doctors report that patients who use cannabis over time tend to wake up less refreshed, suffer from concentration difficulties the following day, and sometimes also from a decline in mood. Some do not associate this with cannabis use, because they still experience rapid sleep onset, but sleep quality is impaired beneath the surface.
Cannabis (credit: freepik)
Another problem that arises in clinical reports is the phenomenon of tolerance. As cannabis use continues, the body becomes accustomed to the effect, and the user requires a higher dose to achieve the same sedative effect. When attempting to stop or reduce use, a withdrawal syndrome sometimes appears that includes severe insomnia, frequent awakenings, intense dreams, and even nightmares. This phenomenon is well described in medical reports and reinforces the claim that cannabis is a short-term solution that may create functional dependence.
The CBD component, which is considered no less controversial, is also not free of ambiguity. Medical reports note that CBD may reduce anxiety in some people, but its direct effect on sleep is not uniform. In some users it is actually stimulating, especially at low doses, and does not guarantee consistent improvement in sleep quality.
In this context, sleep physicians emphasize that cannabis is not a first-line treatment for insomnia. It does not solve the deeper causes of the problem, such as poor sleep hygiene, mental burden, depression, or other sleep disorders. Its use may mask the real problem and make accurate diagnosis and treatment more difficult.
What can people who have difficulty sleeping and are not interested in relying on cannabis or sleeping pills do. Medical reports repeatedly return to the same basic but effective recommendations, maintaining fixed sleep hours, avoiding screens before bedtime, regular physical activity, and reducing caffeine and alcohol in the evening hours. In persistent cases, cognitive behavioral therapy for insomnia is considered one of the most effective and safest tools.
The conclusion emerging from medical reports is clear. Cannabis can help with falling asleep, but it does not guarantee better sleep, and sometimes even harms it. It is a temporary solution that may exact a price in the long term.
In the bottom line, cannabis is a loan of sleep. It may be granted quickly, but the interest, in the form of impaired sleep quality and dependence, may be revealed later.
Dr. Itay Gal is a specialist in paediatrics, a sports and aviation physician, and a researcher of infectious diseases. The health correspondent and medical commentator of Maariv and a lecturer in the fields of medicine and innovation.
