Seasonal Affective Disorder

Seasonal Affective Disorder SAD is characterised by recurrent depressive episodes occurring during (mainly) the winter months. Patients may also experience symptoms of mania and hypomania during episodes of SAD, although this is more rare.

What is seasonal affective disorder?

We all feel a little more tired when the dark nights draw in and many of us feel like ‘hibernating’ but for some people the changing seasons can have a serious effect on their moods and this is known as seasonal affective disorder.

Women are much more likely to get seasonal affective disorder than men.

Short days, low levels of sunlight and winter grey skies deprive the brain of the light it needs; for some people this can have a serious effect on their mental wellbeing. It is thought as many as 30%¹ people are particularly sensitive to low light levels, which can result in SAD.

Seasonal affective disorder is most commonly associated with the winter months, however some sufferers develop low moods at the onset of summer.

¹ Sloane, P.D., (2003)

Causes of seasonal affective disorder

SAD appears to develop due to reactions to the amount of light available. Reduced light levels has an effect on the brain in terms of:

• circadian rhythm (the body’s internal clock) It is thought that patients with SAD generate a biological signal of change of season, that is absent in non-suffers².
• serotonin levels (serotonin is a chemical in the brain that is linked to feelings of happiness)
• melatonin levels

² Wehr, T. (2002)

Seasonal affective disorder symptoms

People with seasonal affective disorder will experience the onset of a lowering of mood around October, with symptoms that last until about March.

Not everyone experiences severe symptoms, there are thoughts that SAD is like a spectrum – some people will get very ill and won’t be able to do the things they normally do, whilst others will have less severe symptoms but feel more tired, moody and want to withdraw a bit more.

Below are some of the common symptoms of seasonal affective disorder.

• Irritability
• Low energy
• Tiredness and oversleeping
• Hypersensitivity / sense of rejection
• Heaviness in limbs
• Weight gain, craving of certain food groups

Seasonal affective disorder treatment

It is important to obtain a proper diagnosis for seasonal affective disorder to rule out other forms of depression or health issues.

Once seasonal affective disorder is diagnosed, treatments can involve medication, talking therapies and light therapy.

1. Medication: antidepressants can be used in patients who have severe seasonal affective disorder. It is important to see a qualified and experienced clinician, who understands SAD well in order to find the right medication option for you as the symptoms will often diminish in the summer months.
2. Talking therapies: talking therapies, such as CBT, can help the individual work through their low mood and anxieties as well as learning new and healthier ways to cope with the symptoms. Once learnt, these skills will last a lifetime.
3. Light therapy: the treatment includes topping up on light exposure via high intensity light sources such as light boxes and light visors. The source and intensity of the light needs to be carefully managed which is why this disorder and its treatment should be supervised by a specialist who has training and experience with it.
   For example the timing of the light exposure appears to be crucial, and there is some evidence that using high intensity lights at dawn appears more helpful than at other times of the day. Most patients usually respond within 1-2 weeks of therapy.

One recent study found that patients who had light therapy and CBT were more likely to have full remission from their symptoms than light therapy or CBT alone³.

³ WebMD