As the days get shorter and the afternoons get darker, hundreds of people run the risk of sinking into depression.

But health bosses are ploughing millions of pounds into tackling the problem.

Today is World Mental Health Day, and activities are taking place across the West to raise awareness of the issues that affect so many people.

It is estimated that one in four will suffer with depression at some point in their life.

This sometimes manifests itself as Seasonal Affective Disorder (Sad), when a lack of sunshine pushes people into the doldrums.

But figures released this week show that more than half of workers in Bristol would not tell their employer if they had a mental health condition.

And only one in five would feel comfortable revealing their problem to a colleague.

The majority of those questioned said they would feel ashamed or worried that they would be treated differently.

Tim Cooper, spokesman for the Shaw Trust, which carried out the study, said: "Our research illustrates that people in Bristol are still very reluctant to reveal such a condition, particularly in the current economic climate in which workers are concerned about showing any sign of perceived weakness."

The Avon and Wiltshire Mental Health Partnership (AWP) is urging people not to ignore their mental health and is working to break down the stigma attached to conditions such as depression, anxiety and schizophrenia.

It is also working to provide a range of treatments, from classical music workshops to help with depression and anxiety, to anger management classes.

A spokesman for AWP said: "We are increasingly living busier lives. Forgetting to take time out for ourselves can impact on our mental health and wellbeing."

In Somerset this week, people have been taking part in Soul Walks that aim to boost mental wellbeing.

Walks of between 30 minutes and two hours have already taken place in Yeovil, Taunton, Bridgwater, Frome, Wells, Chard, Minehead and Burnham-on-Sea, with two more scheduled to take place at 10.30am today at Westhay Moor and Steart nature reserves.

Louise Finnis, of Somerset Primary Care Trust, said: "There is good evidence to show that getting out of the house and walking with others helps relieve conditions such as stress and depression. Walking is a great way to lift your spirits, reduce stress, improve sleep, reduce your blood pressure and increase your overall level of energy."

The British Acupuncture Council (BAC) says more people are turning to the practice to help them deal with everyday stresses and strains.

A spokesman for the BAC said: "With people working longer hours and dealing with the economic and social pressures of today, many are finding it hard to cope."

Research by BAC suggests that the top three emotional issues for which acupuncture treatment is sought are depression, anxiety and insomnia, followed by stress.

Acupuncturist Gisela Norman is offering free consultations between 10am and 6pm at the Kingswood Natural Health Centre today.