Journaling for Sleep: What One Bedtime-Writing Study Really Shows

A five-minute to-do list before bed has become one of the internet’s favourite sleep tips. The study behind it is real, randomised, and used polysomnography. It is also small, narrow, and frequently asked to prove far more than it tested.

The careful conclusion is useful enough: in one laboratory night, healthy young adults assigned to list future tasks fell asleep faster on average than those assigned to list completed activities. That makes a short to-do list a reasonable thing to try. It does not make “bedtime journaling” a treatment for insomnia, prove a working-memory mechanism, or tell us that gratitude and emotional writing have predictable opposite effects.

The study behind the headline

Michael Scullin and colleagues published the polysomnography study in 2018. Participants spent a night in a controlled sleep laboratory and were randomly assigned to write for five minutes immediately before bed.

One group listed everything they needed to remember over the next few days. The other listed tasks they had completed over the previous few days. The future-task group fell asleep about nine minutes faster on average.

That design has genuine strengths: random assignment and an objective measure of sleep onset. Its boundaries matter just as much:

• there were 57 analysed participants;
• they were healthy adults aged 18–30 rather than an insomnia sample;
• the experiment covered one night in a laboratory;
• there was no no-writing group;
• it compared two writing topics, not journaling versus no journaling;
• it did not test whether an effect persisted at home.

Within the future-list group, more specific lists were associated with faster sleep onset. That was a correlation inside a small condition, not random assignment to “specific” and “vague” lists. It cannot establish specificity as the cause.

The “offloading” explanation remains a hypothesis

The intuitive story is that unfinished tasks occupy attention, and writing them down gives the mind permission to stop rehearsing them. That may be what happened. The experiment did not measure the proposed chain from writing to working-memory load or cognitive arousal and then to sleep.

So describe the result, not a mechanism the study did not establish:

In this sample and comparison, a short future-task list preceded faster sleep onset than a completed-task list.

That sentence is less dramatic than “clear your working memory in five minutes,” but it is also more accurate.

What the gratitude research does not add

A frequently cited 2009 study by Wood and colleagues found associations among dispositional gratitude, pre-sleep cognition, and self-reported sleep in 401 adults. It did not randomly assign people to a gratitude journal at bedtime. It therefore cannot show that writing three grateful things reduces racing thoughts or improves sleep.

Other small studies have tested gratitude tasks with subjective sleep measures. They use different participants, instructions, controls, and outcomes. Taken together, they do not establish a standard gratitude-journal dose or show that gratitude and to-do lists work through two proven complementary mechanisms.

If a gratitude entry feels welcome, you can try one. Do not force positivity, and do not treat an observational association as a sleep prescription.

Emotional writing: a null result is not evidence of harm

A 2009 randomised study tested an expressive-writing task in adults with primary insomnia and did not find a clear sleep benefit against its comparison condition. That result does not show that emotional writing near bed generally worsens insomnia. Nor does research associating rumination with poor outcomes prove that a particular journal entry caused a longer sleep latency.

The practical boundary can stay personal:

• if emotional writing helps you close the day, that is useful information about your experience;
• if it reliably makes you more activated, move it earlier or choose a lighter topic;
• if writing intensifies distress, stop rather than interpreting discomfort as progress.

No evidence reviewed here establishes future-oriented or positive writing as categorically safer than open reflection.

How long and when?

The direct study used five minutes immediately before bed because that was its protocol. It did not compare five with ten or fifteen minutes, nor immediate writing with a session thirty or sixty minutes earlier. There is no research-backed “five-to-fifteen-minute window” for bedtime journaling.

For a personal test, choose a short boundary that will not displace sleep. If writing itself feels stimulating, move it earlier. If a clinician has given you stimulus-control instructions as part of cognitive behavioural therapy for insomnia, follow that individual plan rather than a blog routine.

The Sleep Foundation’s overview of insomnia treatment describes stimulus control as one component of CBT-I. General advice to reserve the bed for sleep is not evidence that every journal must be written at a desk, and sleep-hygiene tips alone are not a substitute for treatment.

Paper or phone

The Scullin study used paper. It did not compare paper with a phone.

Paper avoids notifications and emits no light, but a notebook may be inconvenient, inaccessible, or easy for someone else to find.

A phone can offer dictation, larger text, reminders, search, backup, and encryption. It can also lead to messages, feeds, and more screen time. Night mode changes the display; it does not remove every possible behavioural effect of using the device.

Choose the medium that lets you complete the intended note and disengage. If the device pulls you elsewhere, use Do Not Disturb, a direct shortcut, or paper. If paper creates privacy or accessibility problems, use a carefully configured digital option.

A modest way to test the finding

If you want to reproduce the idea rather than claim to reproduce the trial:

1. Before bed, spend up to five minutes listing future tasks you do not want to forget.
2. Write enough detail to make each item actionable, if that feels calming rather than demanding.
3. Close the list; do not turn it into a full planning session.
4. Notice whether you feel calmer, unchanged, or more alert.
5. Stop or move the exercise if it repeatedly interferes with sleep.

Your home trial cannot tell you whether writing caused a change, especially when sleep varies with stress, schedule, caffeine, light, illness, medication, and many other factors. It can tell you whether the routine is tolerable and practically useful.

Avoid promising yourself fourteen nights or combining to-do, gratitude, and future-positive prompts as if that package were validated. Test one small change first.

When to seek more than a journal

Difficulty sleeping occasionally is common. Persistent insomnia is a clinical problem with established assessment and treatment options, especially CBT-I. A notebook should not delay care for ongoing sleep problems, severe daytime impairment, breathing concerns, unusual night-time behaviour, or a mental-health crisis.

If writing raises an immediate risk of harm, close the journal and contact appropriate local emergency or crisis support.

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Frequently asked questions

Does journaling before bed help you sleep?

One 2018 laboratory study found that 57 healthy adults aged 18–30 who wrote a five-minute future-task list fell asleep about nine minutes faster on average than participants who listed recently completed activities. It did not include a no-writing group, test people with insomnia, establish a general journaling effect, or show that offloading caused the difference.

What should you write before bed?

A brief future-task list is the format with the clearest direct sleep-onset result, but only from one small study and one comparison. Gratitude and emotional-writing studies answer different questions and do not establish a second best format. Choose a tolerable topic and treat it as an experiment rather than treatment.

Is it better to journal in the morning or at night?

Research does not provide a general winner. The Scullin study only tested a future-task list immediately before a laboratory night; it cannot show that evening is better for reflection, mood, or ordinary journaling.

Can journaling at night make insomnia worse?

Writing can feel activating or distressing for some people, but evidence does not prove that open emotional writing generally worsens insomnia or that structured writing is safer. If a bedtime entry repeatedly leaves you more awake, move it earlier, change topic, or stop. Persistent insomnia deserves evidence-based care.

Is paper or a phone better for bedtime writing?

No head-to-head study establishes one journal medium as better for sleep. Paper avoids notifications and screen light; a phone may offer accessibility, reminders, and secure storage. Choose based on your actual response rather than a universal rule.

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Further reading

• Morning Pages — claims and evidence around the morning counterpart
• Can Journaling Support Mental Health? — what broader writing research can support
• How to Start a Gratitude Journal — no universal frequency, timing, or format
• The 5-Minute Journaling Method — an editorial routine, not a sleep dose
• The Best Journaling Apps for Anxiety and Depression — app features without treatment claims