IT’S the third Monday of January, which of course means it’s Blue Monday.

Much is made of the supposedly dreariest day of the year but experts refute whether the term is true at all.

The history behind the phrase also calls into question whether it's a real phenomenon, or a simple marketing ploy.

What is Blue Monday?

Blue Monday is said to be the saddest day of the year.

The idea is that the post-Hogmanay period provides the perfect petri dish of stress, worry and sadness to create a day that is bluer than any other.

It appears to make sense that after Christmas, when wallets are strapped, and  Hogmanay's resolutions are guiltily tossed out the window, people's moods would be lower.

And on top of a return to work, winter sees a decreased level of sunlight reaching our eyes which can lead to seasonal affective disorder - commonly abbreviated as SAD - in many people.

READ MORE: Top 10 tips to beat Blue Monday - See the full list here

But with December 21 being the winter solstice in the Northern Hemisphere (meaning the days are already getting longer and brighter), and most people already having been back at work for weeks, is January 17 just an arbitrary date?

Where did it come from?

The idea was apparently coined by psychologist Cliff Arnall in 2004. He was asked to come up with a “formula” for January blues by the holiday firm Sky Travel.

The company then used the term in a press release to promote its upcoming deals. The term itself is still often used by companies to promote deals, with much of the marketing aimed at easing winter blues.

The formula looked at a number of factors contributing to low mood. They included weather, debt, monthly salary, time since Christmas, time since failing new year’s resolutions, low motivational levels and feeling a need to take action.

Is there any evidence it is real?

In short, no. Mental health charity Samaritans has gone as far as to call the entire concept a “myth”.

And even Arnall himself later retracted the idea, urging people to “refute the whole notion” of Blue Monday.

He told The Telegraph in 2013: “I was originally asked to come up with what I thought was the best day to book a summer holiday but when I started thinking about the motives for booking a holiday, reflecting on what thousands had told me during stress management or happiness workshops, there were these factors that pointed to the third Monday in January as being particularly depressing.

“But it is not particularly helpful to put that out there and say 'there you are'.”

He also added that there are fears Blue Monday could act as a self-fulfilling prophecy.

Christopher Hand, a senior psychology lecturer at Glasgow University, told The National that there “isn’t compelling evidence for specific days, or even particularly predictable patterns at when collectively, people would really experience this type of thing”.

The National:

Experts say there is no evidence Blue Monday exists

He said it is normal for people to have peaks and troughs in their mood throughout the year.

“The concept of Blue Monday in itself is problematic,” he said. “Because it maybe suggests that there is one specific factor that may be driving people’s mood and their wellbeing.

“This idea of there being one particular focal point in Blue Monday is not supported, and is not scientific at all.”

Rachel Cackett, executive director of Samaritans Scotland agreed. She told The National: “We know that Blue Monday is a myth invented by some very clever travel company to sell holidays.

"And while winter can be tough, with long dark nights and cold or dreary weather, the truth is any of us can struggle with our mental health, at any time of year, for a wide range of reasons."

What if my mood is low on Blue Monday?

Samaritans encourage people to change Blue Monday to Brue Monday – a time to catch up with friends and family over a cup of tea or coffee.

READ MORE: Nearly a third of calls to NHS Scotland’s mental health crisis hub abandoned

“At Samaritans we know there’s no such thing as ‘Blue Monday’,” the mental health charity said. “We all have our good days and our bad days, and those aren’t for the calendar to decide.”

The National: Exercise need not be expensive

Scots are advised to get outside and receive as much sunlight as possible during the dark winter months

Cackett continued: "Our Brew Monday campaign isn’t about beating ‘Blue Monday’ or the ‘January Blues’; instead, it’s about encouraging everyone to make time to talk and to listen.

"By making time to connect over a cuppa and a chat, catching up via video call or even dropping someone a text just to check in, we can all show that we’re there to listen and support mental wellbeing, not only on Brew Monday but throughout the year.”

Hand said we must look after our mental health all year round, but had some tips for people who may be feeling low.

Getting more daylight, improving your diet, exercising, getting proper sleep and asking for help when appropriate are all things people can do to help their mental health.

Where to get help

SAMH gives mental health information and can direct you to local services.

Call 0141 530 1000 or email enquire@samh.org.uk If you need to talk, call Breathing Space on 0800 83 85 87 or see www.breathingspace.scot

Families who need support after being bereaved by suicide can contact Petal on 01698 324 502 or email info@petalsupport.com

Call Samaritans for free on 116 123 or email the charity at jo@samaritans.org.