SAD: Tips for a Happier and Healthier Winter
At this time of year, as the days become darker, many of us find that we are travelling to and from work in the dark. This lack of sunlight can have a tremendous effect on us, affecting our mood and appetite, and creating a greater need for sleep. These symptoms are typical of Seasonal Affective Disorder (SAD), a mood disorder affecting around 1 in 15 of us in the UK.
SAD is caused by a lack of sunlight, which in turn affects the body’s production of mood-balancing hormones melatonin and serotonin. These hormones also affect our sleep cycle and appetite, leaving those affected feeling tired and prone to weight gain.
While anti-depressants are sometimes prescribed for SAD, there are a number of natural measures thought to be effective in addressing SAD.
1. Vitamin D and Omega-3
Vitamin D and omega-3 are commonly in low supply in the UK diet. The British National Diet and Nutrition Survey indicates that 25 per cent of British adults have low vitamin D status (1). Low levels of vitamin D have been linked to depression, because this vitamin helps to regulate levels of both serotonin and melatonin.
SAD has been found to be less common in people who have a higher intake of omega-3, present in fish oils and some plant oils. Icelandic and Japanese populations have a high intake of fish, and a low prevalence of SAD. Seafood consumption has also found to be linked to lower rates of major depression (2). Like vitamin D, omega-3 helps to modulate the mood hormone serotonin.
2. Physical Activity
Exercise is well-known to boost levels of endorphins, lower stress levels and improve sleep quality. Regular exercise is therefore recommended. A recent Cochrane review concluded that exercise is effective in reducing symptoms of depression, with aerobic exercise being particularly effective. Michael J Rice, a professor of psychiatry at Nebraska Medical Centre, advises that those with SAD should make a concerted effort to exercise throughout the winter months, and that exercising outdoors is particularly beneficial (3).
3. Light Therapy
Thought to be the most effective treatment for SAD, light therapy has a beneficial effect on levels of melatonin, and increases blood flow to areas of the brain affected by SAD. Light therapy is also thought to affect levels of serotonin and the stress hormone cortisol. There have been more than 60 randomized, controlled trials of light therapy for SAD, and almost all of these studies have shown positive benefits.
Light boxes can be bought for home use, and are most effective when used daily and in the morning for around 30 minutes. For those experiencing SAD, the positive benefits should be felt after just a couple of weeks.
Anyone choosing light therapy should ensure that they are using an effective device, as some devices may not emit light at an effective intensity. In light therapy treatment, the intensity of the light is directly linked to the effectiveness of the treatment. Compared with placebo, bright light at levels of 6000 lux was found effective for patients with depression. Patients received bright light for 1.5 hours each day, while the placebo group used a sham device. More recently, a randomized trial published earlier this year found that just 30 minutes exposure to a bright light device is effective in treating depressive symptoms (4).
For anybody experiencing SAD, the dietary, lifestyle and light therapy measures above are possibly the safest and most natural ways of bringing the body back into balance. For those beginning to feel the winter blues this month, taking action early can help to ensure a happier and healthier winter.
1. National Diet and Nutrition Survey (NDNS) Rolling Programme. May 2014. Food Standard Agency.
2. Hibbelm JR (1998) Fish consumption and major depression. Lancet 351:1213
3. SAD no more: preparing for seasonal affective disorder. www.everdayhealth.com. Visited 31/10/2016.
4. Lam et al (2016) Efficacy of bright light treatment, fluoxetine, and the combination in patients with nondeasonal major depressive disorder. A randomised clinical trial.