‘This groundbreaking tool will change your life,” claims MindJournal, a £9.99 collection of quizzes and writing exercises that it claims will “encourage you to be more honest with how you’re feeling”. Aimed at a male audience, it has a testosterone-fuelled tagline: “Become a stronger version of the man you already are.”

It’s not unique; in bookshops, it has quickly evident that the humble notebook is having an overhaul. Prescriptive travel diaries (“Enjoy the lightly guided prompts for agendas, lists and observations”) bump up against journals claiming to focus on inner truth (“Featuring over 70 thought-provoking quotes from fellow self-improvers, this journal is great for both perfectionists and failures!”), while the latest fad for bullet journalling – a convoluted to-do list system – has swept the internet, inundating Instagram with a pages of artfully annotated checklists.

The simple act of putting pen to paper to record one’s daily thoughts and reflections, it would appear, has been commercialised and disrupted. But does keeping a journal offer any tangible rewards? It’s a promise that is often claimed to be rooted in research – MindJournal’s website, for one, points out “there’s a shedload of scientific evidence to support the power of writing”.

The premise that keeping a journal is good for you often comes back to the seminal work of American social psychologist James Pennebaker, based at the University of Texas at Austin. In the 1980s, Pennebaker revealed that, compared with writing about a trivial topic, writing about important emotional events for a set period was linked to study participants being emotionally churned up in the short term but making fewer visits to health professionals in the six months that followed. The practice has since been linked by researchers around the world to myriad health benefits, from improving mental health to helping wounds heal faster.

Known as “expressive writing”, the approach is based on individuals writing about their deepest thoughts and feelings for 15 to 30 minutes a day and is usually carried out on only a handful of occasions over a period of days or weeks. Its effects appear impressive. A meta-analysis of 146 expressive writing studies, carried out by Joanne Zinger (nee Frattaroli) of the University of California, Irvine, found benefits across psychological health, physical health and even specific disease-related symptoms.

In one study, researchers found that 11 days after having a punch biopsy, 76% of those who carried out expressive writing in the two weeks before the biopsy were found to have completely healed wounds, compared with 42% who wrote about time management. Other research has further revealed that the benefits are greater in those who undertake expressive writing before receiving such a wound, compared with after, possibly, at least in part, due to the reduction in levels of stress hormones, which affect the immune system.

But not every trial into health impacts shows a benefit. John Weinman, professor of psychology as applied to medicines at King’s College London, is among those to have carried out research into the impacts of expressive writing.

“We know it is not a universal thing,” he tells me. “We know there are quite a few studies where it hasn’t been shown to be effective and certainly when you look at cohorts of people, some people seem to gain a lot more benefit than others.”

In one study by Elizabeth Broadbent from the University of Auckland, patients about to undergo weight-loss surgery participated in an expressive writing trial. But the team found that those who had written factually about their daily activities fared better than those who had recorded their deepest thoughts and feelings. “We think that writing emotionally before surgery was not helpful because patients were writing about an upcoming stressor – surgery – rather than past stressors, so it did not make them feel better,” Broadbent explains.

Zinger also admits that the practice doesn’t help everyone. “This type of intervention may be more helpful for certain types of individuals, such as those who don’t have much social support,” she tells me. “In my 2006 meta-analysis, I found that participants who were higher in stress and/or who were more pessimistic benefited from expressive writing more than participants who were lower in stress and/or who were more optimistic.”

Pennebaker is also aware of the issue of predicting who will benefit. “I think this is one of the biggest challenges facing the expressive writing literature,” he says. According to Pennebaker, the lack of benefit in some trials might also be a consequence of the intervention lasting for such a brief period: “Even most medical procedures take more time and also have very, very low effect sizes over weeks or months.”

A journal by Instagram user @janiegirlcrafts. Photograph: @janiegirlcrafts/Instagram

But even if expressive writing can offer benefits, to what extent can such research, based on a very specific format, be used to support the idea that keeping a journal is good for you?

Pennebaker is cautious, pointing out that studies have focused on expressive writing regimes rather than general journal keeping. “My view is a bit more sceptical. Show me the data and I’ll believe it,” he said. “I haven’t seen the data yet, because to my knowledge, no one has tested it.”

Broadbent agrees: “To my knowledge, we cannot extrapolate the effects of expressive writing to journal keeping.”

But Annette Stanton, professor in health psychology at the University of California, Los Angeles, is more equivocal, pointing to a study from her team that found some benefits for women with breast cancer who took up blogging, including improvement in depressive symptoms and life appreciation.

However, she also warns that benefits can be dependent on circumstances, with one of her studies finding that the impact of expressive writing was different for women who had recently received a diagnosis of breast cancer compared with those who had known their diagnosis for some time. “It is not that this is good for everybody all the time,” she said. “There is some consistent evidence from scores of studies that it can be helpful – it is not truly hit and miss, but again, there are boundary conditions.”

Stanton adds that some studies have suggested that expressive writing can be useful when combined with talking therapies and that “the great majority of evidence suggests that keeping a journal can’t hurt”.

Ollie Aplin is the founder of MindJournal. He is confident his journal can help men, pointing out that journalling has helped him to cope with anxiety, panic attacks and even PTSD. He was advised to pick up a pen, he reveals, while recovering from a breakdown following his mother’s suicide.

“When I was first ‘prescribed’ [journal keeping], if you like, I was a bit cautious – I immediately thought it was just going to be a diary thing and therefore it just felt a bit more feminine to do. But I was also struggling to talk, so I was like, ‘Well, I need something’.”

Journalling allowed him to start sharing his experiences, offering a way to explore his thoughts and to communicate with his therapist when talking was impossible. “Even though she was dead, I was paranoid that [my mother] would storm in and find me talking to a therapist,” he says. “Journalling gave me that ability and that safe place, to learn how to express and to feel what I was feeling so I could talk about it in my therapy sessions; also, I could talk about it to my dad and I can talk about it to my partner.”

Aplin later developed MindJournal. Initially, the project was aimed at everyone, but Aplin soon found that men didn’t feel it was for them. “I think that, sometimes, guys just don’t like the idea of looking after themselves. If you look at journalling as being a self-help thing, I think guys still feel that self-help – apart from exercise – is not a manly pursuit,” he says. “What I have been trying to do with MindJournal is to say, ‘Well, that is a load of crap’.”

The journal is guided, full of prompts asking men to consider their goals, asking them to think about what their role as a man is. “I feel with expressive journalling, almost like emotional therapeutic journalling, you need a sense of guidance and framework,” says Aplin. “You don’t even have to have a mental health problem to be using this thing. It is a healthy habit to track everything you are feeling and going through, just as a way of processing stuff that happened in everyday life.”

Straight, gay and transgender men have all embraced the journal, Aplin says. “I only journal when I am having panic attacks or an anxiety attack; if I am not getting those symptoms, then I don’t journal,” he adds. “But I am also aware of the fact that if I don’t journal, I usually end up having more anxious days and more panic attacks.”

While guided journals such as MindJournal encourage reflection, the explosion of bullet journalling is rooted in the rather broader attempt to Organise Life.

Invented by Ryder Carroll, a Brooklyn-based digital product designer, the Bullet Journal, or BuJo, was unveiled in 2013. As well as Carroll’s commercial journal, he has created free accompanying YouTube videos, meaning anyone can give it a go with a basic notebook. It’s a combination of short-form note taking, drawing and detailed planning and its success is palpable: a glimpse at Instagram reveals page after page of beautifully illustrated, multicoloured and intricately coded charts and calendars detailing tasks, recording emotions and offering an apt quote.

“The Bullet Journal is actually years-worth of me dealing with my own organisational challenges, stemming from suffering from attention deficit disorder from a very young age,” says Carroll. Only after showing his system to a colleague who was struggling to plan her wedding was Carroll encouraged to share his approach with the world.

“It never occurred to me that this would help anyone else, because I designed it specifically for myself,” he admits. “I had to have something that was as flexible as the way that I thought. A lot of times when I have an idea, it starts as an image or feeling or something like that; there was no note-taking system that I have ever been exposed to that not only allowed me to capture the information, but also to find it again later.”

Ryder Carroll: ‘It never occurred to me that this would help anyone else, because I designed it specifically for myself.’

In a nutshell, the basics of bullet journalling lie in creating an indexed breakdown of the year – each month and each day – with tasks jotted down daily and then either checked off, scheduled or relocated into other parts of the journal. Notes on everything from reading lists to life goals can also be taken and cross-referenced, with a selection of symbols used to add extra meaning to thoughts or events. After the system has been mastered, individuals can tune it to their own needs.

“It encourages people not only to write things down as they happen, but later on to reflect on these items they are working on,” says Carroll. “What starts to happen is you surface the things that do have meaning, that are relevant to your life, which is really the whole purpose of bullet journalling – it is living a lot more intentionally, because of this practice of living with your thoughts, not just writing stuff down and walking away from it.”

It is a curiously analogue approach for someone who spends his time building apps, but Carroll says his offline system is necessary. “As much as technology helps us look outward, it comes at the expense of our ability to look inward,” he says, adding that he also uses the journal for long-form writing. That said, Carroll reveals that there is an app to help enthusiasts catalogue their journals and offer tips.

Turning to pen and paper avoids privacy pitfalls, but if the convoluted designs uploaded by bullet journallers to social media are anything to go by, it is also an excellent way to procrastinate. “Sometimes, that is what people need,” Caroll argues. “Are there people who spend way too much time bullet journalling to no end? I am sure there are,” he adds. “But in my community, a lot of people suffer from depression and anxiety and generalised human conditions and when they spend an hour on their bullet journal they feel better.”

The success of bullet journalling has taken some by surprise, neuroscientist and author Daniel Levitin among them. “One thing I’ve noticed is that the complexity of a system is inversely related to the number of people who will adopt it,” he tells me. “That is, the more complicated something is, the less likely people are to stick with it.”

L evitin suspects the system’s popularity might lie in its power to help individuals externalise their memory. “We used to think that you could pay attention to five to nine things at a time. We now know that’s not true – it’s a gross overestimate. The conscious mind can attend to about three things at once. Try to juggle any more than that and you’re going to lose some brain power,” he says.

Is an in-depth approach such as the bullet journal an advanced tool in the quest for productivity or simply a baffling and unnecessary attempt to make paper, used for several millennia, appear “rediscovered”?

EJ Masicampo, a psychology professor at Wake Forest University, North Carolina, is among those who have looked into the cognitive effects of planning tasks. In one multi-part study, probing the so-called Zeigarnik effect – the phenomenon whereby unfulfilled goals often linger in the mind longer than fulfilled tasks – the team found that those who made a plan for a goal were less likely to be distracted on another task than those who had been asked to think about unfulfilled tasks without coming up with a plan of action.

“If you just take a moment to make a specific plan for a goal that was previously unresolved and worry-inducing, then it gets rid of that stickiness,” Masicampo explains.

While he points out that no studies have yet been carried out on bullet journalling, it is possible that the approach could prove powerful. “There are all sorts of benefits from journalling, from writing things down – certainly from organising your life and making plans and clarifying goals for yourself,” he says.

Masicampo believes bullet journalling – or even simply making canny use of a calendar, as he does – has the advantage over to-do lists of not just coming up with a plan, but assigning exactly when and where a task will be tackled. “The danger of to-do lists is that on any given day you get to pick which things you do. Often, you are picking the easiest things off the list and there is a section of the list that stagnates, so you do the hardest, most undesirable things later,” he says. “Specific is better than vague and having a time set aside is better than leaving it up in the air.”

Levitin adds that the flexibility of a blank notebook might also be part of its appeal. “Research tells us that if you can take time off from your workflow and let your mind wander – maybe doodle, listen to music, draw pictures or even just stare out the window – those periods of inactivity are actually essential to having productive periods of activity,” he says. “When you’ve got a piece of paper in front of you, it sort of encourages you to expand your visual field and expand your imagination.”

That said, he warns that bullet journalling won’t work for everyone. “There is no organisational system on Earth that will,” he says.

But Aplin believes the flexibility of a notebook is what makes journal-keeping so valuable. “That is the great thing about journalling – it is whatever you want it to be,” he says. “MindJournal is literally a notebook with questions in. It is as simple as it gets, but I think sometimes the most powerful tools are the most obvious ones that we are already using.”