Season Affective Disorder – What is it?

Seasonal affective disorder (SAD) is a form of depression that people experience at a particular time of year or during a particular season. It is a recognised mental health disorder.

Most of us are affected by the change in seasons – it is normal to feel more cheerful and energetic when the sun is shining and the days are longer, or to find that you eat more or sleep longer in winter.

However, if you experience SAD, the change in seasons will have a much greater effect on your mood and energy levels, and lead to symptoms of depression that may have a significant impact on your day-to-day life.

Frequency

Most people experience SAD during the winter. Less commonly, some people find they experience SAD in reverse – with depressive symptoms occurring in summer.

SAD is most common in countries like the UK where there are large changes in the weather and daylight hours in the different seasons.

Cause and symptoms of it

The exact cause of SAD isn’t fully understood, but it’s often linked to reduced exposure to sunlight during the shorter autumn and winter days. The main theory is that a lack of sunlight might stop a part of the brain called the hypothalamus working properly.

Symptoms of SAD can include:

  • a persistent low mood
  • a loss of pleasure or interest in normal everyday activities
  • irritability
  • feelings of despair, guilt and worthlessness
  • feeling lethargic and sleepy during the day
  • sleeping for longer than normal and finding it hard to get up in the morning
  • craving carbohydrates and gaining weight

For some people, these symptoms can be severe and have a significant impact on their day-to-day activities.

Treatments

The main treatments are:

  • lifestyle measures, including getting as much natural sunlight as possible, exercising regularly and managing your stress levels
  • light therapy – where a special lamp called a light box is used to simulate exposure to sunlight
  • talking therapies, such as cognitive behavioural therapy (CBT)
  • Medication such as antidepressants in severe cases