Seasonal Affective Disorder is a form of depression, but it is different to other forms in three distinct ways, says Priory consultant psychiatrist Dr Natasha Bijlani.

Dr Bijlani spoke ahead of the clocks changing later this month (2am on last Sunday in October – 31 October), and as preparations are made for a second ‘Covid’ winter. Dealing with SAD in the middle of a pandemic can seem like a double burden when someone is already feeling isolated, lonely and anxious.

Working from home, and Covid concerns, may well increase the depressive aspects of SAD as staying indoors and avoiding venturing outdoors limits our exposure to natural light, says Dr Bijlani.

And while many won’t welcome the idea of winter, snow (if it comes) can actually help, she says, because it has the effect of reflecting what natural light there is.

Dr Bijlani says the difference between SAD and other forms of depression are distinct: “You can usually predict its onset according to the seasons, patients report sensitivity to environmental light, and they respond favourably to bright light therapy.” Bright light therapy is the main method used to treat SAD and is meant to replicate the effect of sunlight on the human circadian rhythm – you can find out more on a site like Luxe Luminous where it goes into more detail.

SAD is a mental health condition, which affects up to 9% of the British population. It can have a significant and detrimental impact on a person’s quality of life. SAD is about four times more common in women, and this is thought to be related to the cyclical secretion of female sex hormones, oestrogen and progesterone,’ says Dr Bijlani.

Dr Bijlani, of Priory’s Roehampton Hospital in south-west London, says: “It is well recognised that SAD may be related to changes in the amount of daylight during autumn and winter months, which can affect the levels of serotonin and melatonin in the brain that influence mood.
“During the night, the brain releases melatonin which contributes to making us feel drowsy and induces sleep. At daybreak, the effect of bright light, coupled with the natural rhythms of the brain, suppresses melatonin. In those susceptible to SAD, not being exposed to sufficient light, on dull winter days, can lead to the development of the symptoms of SAD.”

Last year was a particularly gruelling winter, with national lockdowns enforced at Christmas and again in early 2021. Some of those already suffering with SAD saw their symptoms exacerbated, fuelled by an increase in feelings of uncertainty and less opportunities to get out in search of sparse daylight hours. Whilst working from home afforded some people more flexibility, social isolation, no necessity to travel and the lack of a normal routine may have triggered the condition in those who were predisposed to SAD, and made a pre-existing condition worse or harder to manage. Light therapy is effective in up to 85 per cent of diagnosed cases of SAD, says Dr Bijlani.

Light boxes come in different strengths or lux – the measure of light flow. The lux on a very sunny day is more than 200 times greater in intensity than the light indoors from artificial light on a dark day.

‘A powerful light box might only require the patient to sit for half an hour, whereas a less powerful one might require them to use it for four or five hours a day.’

Dr Bijlani says:

For some people with mild symptoms, these can be alleviated by working in more brightly-lit areas, and keeping blinds wide open during the day
People with “SAD” sometimes need four hours a day of special bright light at 10 times the intensity of ordinary lighting. It’s a very simple treatment, but when used regularly throughout the winter months, it can take away the worst of the feelings. Some people also add things like CBD oils UK to their treatment plan so that they can help distinguish the negative emotions they are having and give their mind a sense of calm, especially on the more dark and difficult days.
Make time for exercise outdoors such as cycling or regular walks. So make sure to exercise outdoors where able, and eat well – foods that are rich in a variety of vitamins are helpful in warding off symptoms of depression. Exercising produces endorphins in the brain (which stimulate feelings of happiness), so try to take a walk at lunchtime, play a sport with family – be active in a way which you enjoy
Be sociable where you can, even if that means remotely. Planning evenings or an afternoon talking with a friend, even if on the phone or Zoom, can be a way to give structure to your day and avoid loneliness and negative thoughts or feelings
Don’t sleep in too late. Staying in bed too long will limit your exposure to light and excessive sleeping contributes towards lethargy
Psychological treatment focusing around cognitive behaviour therapy – a talking therapy – can also be helpful. Priory Connect is an online video therapy which can be accessed from home
If problems persist and you are concerned about symptoms of depression, talk to your GP or contact the Priory. Doctors may also prescribe selective serotonin reuptake inhibitors (SSRIs)

My Possible Self is a free mental health app, with information provided by Priory mental health experts, which is available here https://www.mypossibleself.com/