Can writing a diary protect your mental health?

When the government's chief scientific adviser started a "brain dump" of diary entries on the Covid crisis in 2020, he says he did not expect - or want - it to be published.

The high-profile scientist is far from alone among diarists in predominantly writing for themselves as a kind of therapeutic ritual.

In the modern world - often seen as overly fast-paced and digital - could something as simple as keeping a handwritten diary help clear our heads?

Julia Samuel, a psychotherapist and author of Grief Works, believes so.

She told BBC Radio 4's Today programme on Tuesday: "It's very well evidenced that when we write what we feel we release our emotions as we would when we talk.

"In fact, writing a journal is as effective as talking therapies - it helps regulate emotions, anxieties and stress, it even improves our immune system, our mood and it often problem-solves."

Ms Samuel added that whether diaries are meant to be read subsequently or not, "it is the release of emotion and the clarification by writing that calms us".

That would suggest that diarists writing in the knowledge - or perhaps hope - that their thoughts will be read by others can also benefit from the soothing effect it can have.

Yet former doctor Adam Kay says writing for a wider audience changes the way you explain things.

"My diaries are now an awful lot better written, but they are less helpful for me psychologically because I know full well that at some point I am going to be emailing them off to a publisher," he told Today.

His entries, which he first tentatively read out at the Edinburgh Festival Fringe in 2016, have since been turned into a book called This Is Going to Hurt and an award-winning TV series with the same name.

The author began writing a diary with the intention of his thoughts remaining private. Mr Kay believes the diary was his way of coping amid the pressures of a hectic working life.

He joins a long line of diarists who have captured the public imagination, from Samuel Pepys' works in the 1600s to the likes of Anne Frank, Alan Clark, Tony Benn, Sasha Swire, Alan Rickman, Captain Scott, Nella Last and Lena Mukhina.

The late Queen's private diary, were it ever to be published, would undoubtedly cause a huge stir, particularly since she reportedly placed significant importance on the entries.

Travis Elborough, the author of Our History of the 20th Century: As Told in Diaries, Journals and Letters, told BBC News that writing diaries can offer society, as well as individuals, benefits now and in the future.

Alongside "being an outlet for creativity" for writers, he says diaries of the past can offer lessons about original responses to previous innovations.

Mr Elborough says that often includes points "that more official sources fail to notice or simply neglect to mention."

Exeter University historian Alun Withey believes diaries can be "extraordinarily rich historical sources", useful records of daily life or a reminder of memorable personal events.

But there can also be negatives, like feeling guilty when you haven't kept up to date, as Kathryn Carter explains to BBC News.

The Wilfrid Laurier University professor, who teaches courses on autobiography and life writing, argues that diaries are not really ever private, regardless of what the author intends.

"I would suggest that, quite aside from the long history of diary writing as a fairly public activity, it is not always intended to remain private even in contemporary times," she explains.

Mr Elborough also highlights how people reading a diary critical of them can be upset, a point echoed by Dr Withey, who adds that regular writing requires effort and discipline.

The historian also cautions that some diaries can deliberately exclude or include things for the author's own ends.

But Sir Patrick explained to the Covid inquiry that he felt a few minutes jotting down some thoughts each evening helped him "concentrate on the following day".

He said he then put his diary in a drawer and "never looked" at it again.

Yet his notes ended up adding to a host of disclosures at the Covid inquiry, with those personal thoughts morphing into damning public criticisms of the government's pandemic response.

Whether he found that transformation therapeutic or not may be something he only tells his diary.

How does keeping a diary help you? Share your experiences by emailing haveyoursay@bbc.co.uk.

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