That time of year is upon us. The days are shortening and the evenings are getting longer, darker and more oppressive. For some, this welcomes the arrival of roaring fires, oversized knitwear and the anticipation of the Christmas festivities. For others, it arrives with a sense of trepidation and a mourning of al fresco dinners and lazy days in the sunshine.
It’s common for people to feel a little low as the winter months creep in, but what’s the difference between this and actually suffering from Seasonal Affective Disorder, a variant of depression? As with many mental health illnesses, people tend to self- diagnose and label themselves nonchalantly as having SAD, which can undermine the severity of the disease for those who it truly affects. I thought I’d take the opportunity to raise awareness about SAD. As always, if you’re concerned you may be affected, please see your doctor.
So, what is SAD?
SAD is a condition that affects you, as the name suggests, within a certain season- usually Winter. It involves some of the common symptoms of depression such as low mood, loss of energy and tiredness, but also includes some of the less common symptoms such as increased appetite, craving carbohydrates and weight gain. The official criteria for diagnosing SAD include an onset of these depressive symptoms in Autumn or Winter, which completely resolve at a predicted time of year, such as Spring. The person should have had had two such episodes in the last two years, and if they have a history of depressive episodes, the seasonal symptoms should significantly outweigh episodes at other times of year. Episodes generally last about 4 months, and up to 60% of patients will suffer in the longterm. Some patients will have complete resolution of symptoms a few years after diagnosis.
It affects around 6% of adults in the UK, with it being much more common in women of reproductive age. There’s also thought to be a genetic link.
What Causes SAD?
There are a few theories about the cause of SAD. A genetic element could affect the production of serotonin, often known as “the happy hormone”, with less production in the Winter months. It’s also thought that the hormone melatonin, which controls the daily sleep-wake cycle, known as the circadian rhythm can be altered in patients with SAD; the less sunlight there is, the more melatonin is produced.
So, How Can It Be Treated?
Fortunately, there are several treatment options which have been found to help those that suffer from SAD.
I’m sure most of you have heard of this one. It’s possible to buy fluorescent light boxes to help with SAD for around £200, but they’re not available on the NHS. It’s not quite understood how they work, but it’s thought that the morning bright light helps to balance the disturbed circadian rhythm in people with SAD. The light box is set to a particular schedule where the brightness of the light box gradually increases over 90 minutes while the patient is sleeping. It’s hard to know what the best “dosage” is or how well it truly works, given it’s hard for the clinical trials to account for placebo effect. Generally, the dosage will be a result of individual trial and error. The light box is usually used until the time when the depressive episode usually ends, and if episodes occur every year, it’s common to start using it before symptoms appear.
It can cause some unwanted side effects, such as headaches, visual disturbance and nausea, but the benefits of treatment usually outweigh the side effects.
Cognitive Behavioural Therapy (CBT)
CBT is the cornerstone of treatment for depression, so unsurprisingly has a role in the treatment of SAD. A clinical trial actually showed that a year following treatment with CBT, none of the patients had a relapse in symptoms compared to a staggering 62% relapse rate in the patients that only received light therapy. Other trials , however, have reported a similar improvement with both light therapy and CBT.
As mentioned before, one of the possible causes of SAD is altered production of the hormone, serotonin. As with depression, the use of a medication called selective serotonin re-uptake inhibitors (SSRIs) which help stabilise serotonin are often used in SAD, especially in those that have long term symptoms. It often takes up to 6 weeks for an SSRI to improve symptoms, which means it may not be that useful as light therapy or CBT as a short term treatment option.
Often the simplest changes in lifestyle can result in huge benefits, and this certainly applies to both depression and SAD. Taking regular exercise, getting as much sunlight as possible and eating a healthy diet can all help improve the symptoms of SAD.
Seasonal Affective Disorder can be debilitating for the sufferer and is more than just feeling a little glum when the weather changes. Fortunately, there are treatments which are proven to work, so it’s worth getting help sooner rather than later. If you think you may be affected by SAD, talk to your GP for advice or head to The Seasonal Affective Disorder Association for more information and support.
Reference: BMJ 2010;340:c2135