Those with dark-coloured eyes at higher risk of Seasonal Affective Disorder (SAD)

Feeling blue in winter? It may be due to Seasonal Affective Disorder (SAD). Do you have dark coloured eyes? You are at a greater risk of suffering from SAD. A new research published in Open Access Journal of Behavioural Science & Psychology has shown how people who have dark/brown eyes ‘demonstrate higher levels of SAD‘ when compared with those with light/blue eyes. The study notes that ‘an individual’s mood varies with the seasons such that the sufferer is often ‘up-beat’ in summer, being high spirited and full of energy but, in contrast, depressed in winter with low spirit and lethargy.’ The study examined ‘the relationship between eye colouration and levels of reported mood variability with the seasons.’ With regard to eye colouration, ‘a significant difference was uncovered between blue/light eyed and brown/dark-eyed individuals across the samples with the latter self-reporting higher levels of mood variability with the seasons. The possible reason could be due to the possibility of blue eye colour having evolved to ameliorate the effects of living at latitudes away from the equator.

What is Seasonal Affective Disorder?

According to the research, Seasonal Affective Disorder (SAD) is a form of recurrent depression which has a seasonal pattern. In the most common form, winter SAD, periods of low mood occur during the winter months, accompanied by an increase in sleepiness, a shift to high starch foods and social withdrawal. In contrast, during the summer, such sufferers are frequently described as upbeat and demonstrate insomnia and high levels of activity. Winter SAD occurs in between 1-10% of the population depending, in part, on the latitude at which the sufferer lives. In the case of summer SAD, low mood occurs during the summer months, although this tends to be an anxious form of depression rather than a lethargic one and there is remission during the winter. Summer SAD is only observed in about 10% of the proportion of winter sufferers, says the study.

Symptoms of Seasonal Affective Disorder

Some of the symptoms of SAD are sad mood and low energy, irritability, frequent crying, feeling tired and lethargic, having difficulty concentrating, sleeping more than normal, lacking energy, decreasing their activity levels, withdrawing from social situations, craving carbohydrates and sugars, and tendency towards weight gain weight due to overeating.

How to treat Seasonal Affective Disorder

Light therapy which seeks to replace the diminished sunshine with bright artificial light, also known as Bright Light Therapy (BLT) or phototherapy is popular. Antidepressant medication is a viable and often convenient treatment for SAD. Taking Vitamin D before winter darkness sets in may help prevent symptoms of depression. Exercise could also play a vital role.