When you begin to sink into a prolonged depression, a number of things can be seen, by others, to happen.

Most notably, you withdraw from your social contacts and become more physically stuck in place. In a bed or on a couch. Little physical activity, if any, can be observed.

Leading up to this, you’ve been suffering from poor sleep.

Naturally, when you eventually turn to your GP or psychologist for help they encourage you to make regular contact with friends and family.

And you’re urged to restore a sleep pattern that is consistent and features seven to nine hours of rest.

It’s terrific advice for everybody

In a November 2020 study,  UAE researchers investigated the effects of social isolation and troubled sleep during the early days of the pandemic.

They found: “The risk for elevated levels of depression symptoms was 63 per cent lower in individuals who reported higher levels of social support compared to those with low perceived social support.

“Similarly, those with high social support had a 52 per cent lower risk of poor sleep quality compared to those with low social support.”

But, of course, it’s very hard to pick up the phone and call your mates when you’re sleep-deprived and stuck in a hole (see here for common traps that can keep you in depression).

Prevention is so important

In the past three weeks, we’ve published several pieces that looked at how modifiable lifestyle factors can have an out-sized effect on preventing or aggravating our most serious health conditions.

In one of these we reported that more than half of all heart diseases worldwide were linked to poor lifestyle. Turn that around: Improve your level of physical activity and quit smoking, for example, and you may avoid a heart attack, stroke or debilitating chronic heart disease.

In another, lifestyle factors were found to predict your chances of developing dementia.

Another advised that lifestyle factors can predict your chances of ending up in a nursing home sooner than later.

And most recently, we reported on eight lifestyle changes that could add 24 years to your lifespan.

In all of these, the message was clear: The earlier you start to clean up your lifestyle, the sooner and greater the benefits.

What is depression?

A multi-faceted study from the University of Cambridge found that seven lifestyle behaviours can increase or reduce our risk of depression.

The study also found that while our DNA – genetic makeup – has an impact on our risk of depression, lifestyle factors are “potentially more important”.

This means moderating your risk of depression is probably more in your hands, than the hand you were dealt with via your genetics.

Good news, right?

The lifestyle behaviours that reduce the risk of depression are much the same as those in the reports I wrote about preventing heart disease, dementia, and living longer.

They are as follows:

• Moderate alcohol consumption
• A healthy diet
• Regular physical activity (exercise)
• Healthy sleep
• Frequent social connection
• Avoiding smoking like the plague
• Limiting your sedentary behaviour (sitting around for hours on end, also known as the new smoking).

To identify these behaviours the researchers examined data from almost 290,000 people from the UK Biobank – of whom 13,000 had depression – followed over a nine-year period.

The factors that matter most

The two factors that made the biggest difference in reducing depression risk were – surprise, surprise! – having a good night’s sleep, and frequent social connection.

When people slip into depression, their contact with friends and family ebbs away.

Sleeping between seven and nine hours a night reduces the risk of depression. This included single depressive episodes and treatment-resistant depression, by 22 per cent.

Frequent social connection reduced the risk of depression by 18 per cent. It was also the most protective against recurrent depressive disorder.

How the other behaviours pay off

According to a statement from Cambridge, in order of effect:

• Never smoking decreased the risk of depression by 20 per cent
• Regular physical activity by 14 per cent
• Low-to-moderate sedentary behaviour by 13 per cent
• Moderate alcohol consumption by 11 per cent
• Healthy diet by 6 per cent.

Of course, the more of these behaviours you adopt or modify, the greater the benefit. Participants who adopted the most number of healthy behaviours were 57 per cent less likely to develop depression than participants who adopted few or no changes.

What about genetics?

So, which has the greatest impact on you developing depression: Your lifestyle, or whatever genetic risk you might carry?

The researchers examined the DNA of the participants, assigning each a genetic risk score. This score was based on the number of genetic variants an individual carried that have a known link to the risk of depression.

Those with the lowest genetic risk score were 25 per cent less likely to develop depression when compared to those with the highest score – which indicated “a much smaller impact than lifestyle”.

And regardless of people being at high, medium, and low genetic risk for depression, “the team further found that a healthy lifestyle can cut the risk of depression”.

Professor Barbara Sahakian, from the Department of Psychiatry at the University of Cambridge, said: “Although our DNA – the genetic hand we’ve been dealt – can increase our risk of depression, we’ve shown that a healthy lifestyle is potentially more important.

“Some of these lifestyle factors are things we have a degree control over, so trying to find ways to improve them – making sure we have a good night’s sleep and getting out to see friends, for example – could make a real difference to people’s lives.”

Professor Jianfeng Feng, from Fudan University and Warwick University, added: “We know that depression can start as early as in adolescence or young adulthood, so educating young people on the importance of a healthy lifestyle and its impact on mental health should begin in schools.”