27 November 2018

Spotting the Signs: Seasonal Affective Disorder (SAD)

Seasonal affective disorder (SAD) is a form of depression which is estimated to affect around one in every fifteen people in the UK between the months of September and April.

The exact cause isn’t fully understood, but it’s thought to be linked to reduced exposure to sunlight. It can have a significant impact on mood.

For some people, SAD is so disabling that they cannot function in winter without continuous treatment. Others may experience a milder version called sub-syndromal SAD or 'winter blues.

What causes SAD?

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, which may affect the:

  • production of melatonin – melatonin is a hormone that makes you feel sleepy; in people with SAD, the body may produce it in higher than normal levels
  • production of serotonin – serotonin is a hormone that affects your mood, appetite and sleep; a lack of sunlight may lead to lower serotonin levels, which is linked to feelings of depression
  • body's internal clock (circadian rhythm) – your body uses sunlight to time various important functions, such as when you wake up, so lower light levels during the winter may disrupt your body clock and lead to symptoms of SAD

What are the symptoms?

According to the mental health charity MIND, symptoms of SAD can include:

– feeling sad, low, tearful, guilty, like you have let others or yourself down; sometimes feeling hopeless and despairing, sometimes apathetic and feeling nothing anxiety

– tenseness and inability to cope with everyday stresses panic attacks mood changes

– in some people, bursts of hyperactivity and cheerfulness (known as hypomania) in spring and autumn overeating

– particularly 'comfort eating' or snacking more than usual being more prone to illness

– some people with SAD may have a lowered immune system during the winter, and may be more likely to get colds, infections and other illnesses loss of interest in sex or physical contact social and relationship problems

– irritability or not wanting to see people; difficult or abusive behaviour greater drug or alcohol use

When to see your GP

You should consider seeing your GP if you think you might have SAD and you're struggling to cope.

Your GP can carry out an assessment to check your mental health. They may ask you about your mood, lifestyle, eating habits and sleeping patterns, plus any seasonal changes in your thoughts and behaviour.


Information from: https://www.nhs.uk/conditions/seasonal-affective-disorder-sad/