IF you’ve noticed your mood slipping as the dark nights draw in, be reassured, you are not alone. Between the months of October to February, up to one in five individuals will suffer with winter blues to some degree. At its’s worst this condition is classified as Seasonal Affective Disorder (SAD) with symptoms as severe as those of depression.

Winter blues and SAD share the same features as depression, including low mood, irritability and tearfulness, and a lack of interest in things which usually are a source of pleasure.

Whereas those with depression typically suffer reduced appetite and difficulty sleeping, persons with SAD may find themselves comfort or even binge eating, as well as sleeping excessively. It is often a struggle to get out of bed in the morning.

However as spring arrives, persons with SAD may dramatically improve, sometimes within the space of just a week.

We aren’t exactly sure what causes SAD, but reduced amounts of light have been linked to an increase in the chemical melatonin in the brains of those with the disorder.

Excess melatonin makes you sleepy. Similarly lower levels of light may also result in a decreased amount of the chemical serotonin, which is involved in controlling your mood, appetite and sleep pattern.

First line antidepressants work to promote the activity of this chemical in the brain.

THE dark nights may also make you more prone to unhealthy behaviours such as craving comfort foods which leave you feeling sluggish.

You may be more reluctant to get out and exercise. Any weight gain can have you feeling guilty and less in control.

It is important not to ignore these signs. If you know you are going to struggle during the winter months, particularly if this is a recurrent issue, it may help to have a plan beforehand.

As with any mental health illness, the basics always apply.

Try to get up and go to bed at the same time each day to regulate your body’s internal clock.

During the daylight hours, aim to get as much light exposure as you can, for example sitting near a window, or going out for a walk at lunch time. Although it’s tempting to comfort eat, maintaining a healthy diet will make you feel better in the long run.

Regular exercise can help, indeed group sports may provide a lot of pleasure.

Evidence suggests that regular exercise also gives you better control over your dietary choices.

Light boxes have become quite popular, although they are not currently available on prescription.

They work by exposing you light, ideally early on in the day, typically for between one and three hours, at intensities several times that of traditional light bulbs. If this therapy is going to work for you, you should notice an improvement fairly rapidly, although you would need to continue it daily during the entire winter.

If you are really struggling, there is never any shame in discussing it with your GP, especially as winter can sometimes feel like it lasts half of the year in the UK.