The shorter daylight hours in winter bring the prospect of seasonal affective disorder for some people. Nerys Hairon outlines how nurses can help affected patients
Keywords: mental health, management, seasonal affective disorder
Hairon, N. (2007) Helping patients to cope with seasonal affective disorder. Nursing Times; 103: 46: 25-26.
The changing of the clocks bringing shorter days and reduced hours of sunlight means that some patients will start reporting symptoms of seasonal affective disorder.
SAD is a type of depression or mood disorder with a seasonal pattern. The most common form is also known as ‘winter depression’. Symptoms usually develop some time between September and November, tend to be worse when the days are shortest (in December, January and February) and generally last until March or April, improving in the spring.
There is also a summer version of seasonal affective disorder. However, this is far less common and has different causes and symptoms from the winter form of SAD.
Around one in 50 people in the UK has SAD (CKS Library, 2007; NHS Direct, 2007). It is more common in women than in men and most often starts between the ages of 18 and 40. CKS Library and NHS Direct explain that up to one in eight people in the UK experience milder symptoms of ‘winter blues’ (sub-syndromal SAD).
Studies around the world have indicated that SAD becomes more common the further people are from the equator. This suggests that SAD is linked to the changes in the number of daylight hours through the year.
The Seasonal Affective Disorder Association (SADA) explains that for many people, SAD is a ‘seriously disabling illness’, preventing them from functioning normally without continuous medical treatment (SADA, 2007). It adds that for others it is a mild but debilitating condition causing discomfort although not severe suffering (sub-syndromal SAD).
Causes of SAD
The exact causes of SAD are not completely clear but the condition appears to be related to changes in the amount of daylight during autumn and winter, which affects the levels of certain chemicals and hormones in the brain. The hypothalamus, which controls mood, appetite and sleep, is also thought to be involved.
Serotonin is thought to play a role in the condition, as reduced sunlight means that less serotonin is produced and people with SAD usually have lower levels than average in winter.
Melatonin, which affects sleeping and waking patterns, is also thought to be a contributory factor as it is produced in higher levels in the dark. People with SAD tend to have much higher levels than average of melatonin in winter.
Research suggests that there are genetic factors behind SAD, as people who have a close relative with the condition are at an increased risk of developing this form of mental ill-health.
Symptoms and diagnosis
SAD is characterised by a wide range of symptoms that can affect people to varying degrees. SAD symptoms usually recur regularly each winter, starting between September and November and lasting until March or April.
NHS Direct (2007) says that diagnosis will depend on whether patients have experienced symptoms during the same seasons for two or more consecutive years. The symptoms of SAD are outlined in box 1, p26. Diagnosis will also depend on whether periods of depression are followed by periods without depression, and if there are no other obvious explanations or causes for the seasonal change in mood.
NHS Direct adds that some of the symptoms associated with SAD are atypical to those that are reported in depression. With depression patients normally lose weight, lose appetite and have trouble sleeping. People with SAD tend to eat more, put on weight and sleep excessively. These symptoms may help to distinguish SAD from other conditions.
Possible treatments for the condition include light therapy, antidepressants and various forms of psychological therapy.
Light therapy – a popular way of treating SAD – involves daily exposure to artificial bright light. This means sitting in front of a specially designed light box, which produces light that is similar to daylight and much stronger than light from a normal light bulb. Ordinary light bulbs emit an intensity of 200–500 lux but, for effective treatment of SAD, a light that produces a minimum intensity of 2,500 lux is needed.
Patients are advised to start treatment in the autumn or winter, as soon as symptoms begin, by sitting a metre away from the box, facing the light but not looking directly at it. The length of light therapy needed varies, depending on the strength of the light – this can range from 30 minutes a day to three or four hours. It is best not to use light therapy late in the evening. Patients should carry on with normal, everyday activities while sitting in front of the light box. Visors and dawn simulators are also available.
According to SADA (2007), light therapy has been shown to be effective in up to 85% of diagnosed cases, while NHS Direct (2007) states it works for two-thirds of people with SAD.
Light boxes are not available on the NHS and have to be bought from specialist retailers. SADA recommends trying before buying and several companies offer home trial or hire schemes. Treatment for SAD should be supervised by a GP or clinic and side-effects, though rare, should be reported to a GP.
Antidepressants and therapy
If a patient’s symptoms are particularly severe, their GP may prescribe antidepressants. Drugs used to treat SAD are usually only prescribed during the winter months, as symptoms tend to improve naturally during the spring.
According to SADA (2007), tricyclic antidepressants are not usually helpful for SAD as they exacerbate the sleepiness and lethargy that characterise the condition. It adds that SSRIs, such as sertraline, paroxetine and fluoxetine, are effective in alleviating the depressive symptoms of SAD and combine well with light therapy.
Counselling, psychotherapy or cognitive behavioural therapy may also be useful in helping patients to manage their symptoms and identify negative thoughts and feelings that may compound symptoms of SAD. Patients should ask GPs about availability.
There are several self-help strategies that nurses can suggest to help patients cope with SAD, especially those with a milder form of the condition.
The following simple lifestyle changes may help to improve symptoms:
Sources: NHS Direct (2007); Mind (2007).
It is clear that many people experience symptoms of seasonal affective disorder to varying degrees in winter.
By understanding the causes of the condition and knowing about the range of treatments and self-help measures, nurses can help patients by improving management of symptoms.
BUPA (2007) Seasonal affective disorder (SAD). www.bupa.co.uk
Clinical Knowledge Summaries (CKS) Library (2007) http://cks.library.nhs.uk
Mind (2007) www.mind.org.uk
NHS Direct (2007) www.nhsdirect.nhs.uk
Patient UK (2007) www.patient.co.uk
Seasonal Affective Disorder Association (2007) www.sada.org.uk