A note on what follows: we are writers and editors reading the research, not clinicians or psychologists. These are patterns measured across thousands of people, and one of the studies below is a survey rather than an experiment. A pattern in a crowd is not a prescription for any one reader’s inner life.
Gratitude journaling has an image problem.
It tends to sit on the same self-help shelf as vision boards and manifestation, and often the reaction to being told to list three good things before bed is a raised eyebrow. That scepticism is healthy. Most wellness advice is untested, and the burden of proof sits with the claim, not the doubter.
So does it survive a proper trial?
The 2025 PNAS review on the topic was a large cross-cultural meta-analysis, pooling results from 145 studies and 24,804 participants from 28 countries. Its conclusion was that gratitude interventions did produce a benefit for well-being, but a small one — a Hedges’ g of 0.19, which in plain terms means the average person who tries a gratitude practice ends up slightly better off than the average person who doesn’t. Not nothing, but nowhere near the transformation the wellness industry sells. The size of the benefit also varied from country to country rather than working like a fixed dose.
A separate 2023 review of controlled trials found a more positive result. Looking at 25 trials with 6,745 participants, Abdurrahman Kirca, John Malouff and Jai Meynadier reported that “expressed gratitude interventions had a significant effect on psychological wellbeing relative to neutral comparison groups, Hedges’ g = 0.22”.
The well-being result gets most of the attention. Two other threads run quieter through the research.
On sleep, a survey of 401 people by Alex Wood and colleagues found that “gratitude predicted greater subjective sleep quality and sleep duration, and less sleep latency and daytime dysfunction.” This was a one-time snapshot, not an experiment, so it shows a link, not proof. Grateful people tended to sleep better. The study cannot tell us which came first.
On helping others, the evidence is quite direct. In a 2006 experiment, Monica Bartlett and David DeSteno of Northeastern University found that “gratitude increases efforts to assist a benefactor even when such efforts are costly (i.e., hedonically negative), and that this increase differs from the effects of a general positive affective state.” In plain terms: the helping was not simply a side effect of being in a good mood. Grateful people took on a real cost to help. DeSteno has since described his own work in stronger terms, writing that gratitude makes people “not only more willing to repay debts or favors to previous benefactors, but also to pay such favors forward to strangers.” That is one researcher summing up his own line of work, best read as a well-supported hunch rather than settled fact.
Why a small effect can still be worth the minutes
A Hedges’ g of 0.19 (for wellbeing) sounds like almost nothing, and for a single practice it nearly is. The reason it may still matter is simple. Gratitude journaling is close to free. It costs a few minutes, needs no equipment, and you can do it as often as you like.
Think of it like a small, easy habit whose value comes from repetition rather than from any single session. Sit down a few times a week. Write down a handful of things you are grateful for. Stop.
The evidence doesn’t promise a gratitude list will make you happy or fix your sleep. What it supports is narrower and steadier: across tens of thousands of people in dozens of countries, the practice tends to shift these measures a little, at almost no cost. Whether a small, reliable nudge is worth a few minutes several times a week is a question the data can inform but not answer for you.
If low mood or poor sleep is weighing on you, a qualified counsellor or doctor is the right person to talk to.
