Seasonal affective disorder (SAD) is thought to affect millions of people in the UK every year and may well be at the root of an annual slump in productivity across the country. What can you do to help your staff beat the winter blues?

Every winter, workplaces across the UK experience a decline in performance, a rise in sickness absence and a subtle shift to a more sombre mood. Millions of people struggle to keep their spirits up during the shorter, darker days of winter – they oversleep, they are lethargic during the day; they feel tense and irritable, they crave carbohydrates.

Seasonal affective disorder (SAD), linked to lack of sunlight between September and April, is thought to be related to a chemical imbalance in the hypothalamus, the part of the brain that controls metabolism, body temperature and blood sugar levels. It is said to affect ten per cent of the population of northern Europe; for most, the symptoms of SAD are relatively mild, but for around two per cent of the population, the condition is so debilitating it can drive them to despair.

In the workplace, SAD can have a serious impact on productivity, morale and individual and team performance. It would be easy to shrug your shoulders and accept the problem; but, with a little imagination, you can help to relieve the symptoms of sufferers at work – and boost the morale of other staff who may also be feeling a little worn out by winter.

Get a lightbox. Light therapy, involving exposure to light around ten times the intensity of ordinary domestic lighting, relieves symptoms in more than 80 per cent of cases. If you have a private space where sufferers can go for half an hour at a time, then a lightbox could be a worthwhile investment. Prices start at around £140, but Lightbox UK also offers a range of other light-related solutions. www.sadbox.co.uk

Encourage winter flexible working. Allow staff to work extra hours during lunch breaks, early in the morning or late in the afternoon, so they can leave the office after lunch on Friday.  The extra few hours of light over a slightly longer weekend could make a significant difference to their mood.

Organise exercise. Daily exercise is an excellent way to give your metabolism a kick and lift the spirits. Organise subsidised gym membership and encourage staff to take classes at lunchtimes or early in the day. You could even organise lunchtime yoga or pilates classes at the office.

Maintain a comfortable environment. Keep your staff are kept in a constant, comfortable temperature. 20-24 degrees Celsius is best. Make sure all areas of the office are well-lit and allow SAD sufferers to sit by windows wherever possible, to maximise the light they receive.

Arrange on-site health screenings. Health checks send out a message to staff that you take their well-being seriously. A check-up can also identify hidden health problems, including SAD.

Give your staff free fruit. SAD sufferers tend to have weakened immune systems and are prone to infections during winter. It is important for them to balance their carbohydrate cravings with plenty of fresh fruit and vegetables. Vitamin B12, found in meat, dairy products and eggs, is also said to be helpful.

Put off major upheavals until the summer. Stress is thought to be a major trigger of SAD and winter is a terrible time for sufferers to experience an upheaval. If you are about to undergo a major change in your workplace, such as a restructure or a move to new premises, consider putting it off until the spring or summer.

• Find out more about SAD from the Seasonal Affective Disorders Association (SADS)
• Mind, the mental health charity, has an informative leaflet about SAD on its website