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Seasonal Affective Disorder (SAD)

Seasonal affective disorder (SAD) is a specific type of depression that one experiences during specific seasons or times of the year. Depression is a low mood that lasts for a long time and affects everyday life.  

SAD is thought to affect around 2 million people in the UK and 12 million people across Northern Europe. It can affect people of any age, including children, although symptoms are most likely to begin between the ages of 18 and 30. Women are reported to be three times more likely to be affected than men. SAD  

SAD begins and ends at about the same times every year. If you are like most people with SAD, your symptoms start in the fall and continue into the winter months, sapping your energy and making you feel moody. SAD is sometimes referred to as ‘winter depression’ or ‘winter blues’ however this is not totally true as less often, SAD causes depression in the spring or early summer too.  


What causes SAD? 

The full causes of SAD are still unknown; however, research suggest the causes of depression are same to for SAD and they are a few other contributors too.  

Weather and temperature: 

We all cope differently to changes in weather, temperatures and seasons. Some people struggle more, and this can lead to depression. There might be some times/occasions of the year others may find difficult due to upsetting memories like anniversaries around death, abuse, money problems. There is new research suggesting of link between higher temperatures and SAD. More work is still needed.  

Effects of light: 

Scientist believe SAD sufferers may have reduced activity of the brain chemical serotonin, which helps regulate mood. They also suggest sunlight controls the levels of molecules that help maintain normal serotonin levels, but in SAD sufferers, this regulation does not work properly resulting in decreased serotonin levels in winter.  

High melatonin levels: 

Another finding suggests SAD sufferers produce too much melatonin. A hormone that is central for maintaining the normal sleep-wake cycle. Over production of melatonin can increase sleepiness.   

Disrupted body clock: 

Both serotonin and melatonin help maintain the body’s daily rhythm which is tied to the seasonal day and night cycle. In SAD sufferers this function is disrupted which leads to sleep, mood and behaviour changes.  

Vitamin D Deficiency: 

May exacerbate these problems because Vitamin D is believed to promote serotonin activity. The body gets vitamin D from diet as well as producing its own vitamin D when exposed to the sunlight in the sun. With less sunlight in the winter, SAD sufferers may have less vitamin D which in turn hinders the serotonin activity.  

What are the symptoms of SAD? 

As SAD is a type of depression, the symptoms of SAD include those associated with clinical depression and on top of that specific symptoms to winter or summer pattern SAD. Presentation differs from individual to individual. 

  • Feeling worthless  
  • Feeling depressed nearly everyday  
  • Having low energy  
  • Feeling like hope is gone.  
  • Loss of interest in things you used to enjoy.  
  • Unable to concentrate 
For Winter-Pattern SAD-some specific symptoms:  
  • Oversleeping  
  • Overeating  
  • Isolating self  
  • Weight gain
For Summer-Pattern SAD-Some specific symptoms:   
  • Poor appetite, leading to weight loss  
  • Anxiety  
  • Restlessness/Agitation  
  • Poor sleep  
  • Episodes of violent behaviors

Moving out of SAD

Many people make their own diagnosis and treat themselves but talking to your GP will give you a proper diagnosis, further information and medically supervised treatment options.

What sort of treatment is there? As with any type of depression the following may all be helpful in reducing or controlling symptoms:

  • Talk to someone
  • Keep a diary
  • Learn ways to relax
  • Try peer support
  • Look after your physical health
  • Plan for more difficult times considering it its Summer/Winter SAD
  • Cognitive behavioural therapy
  • Counselling
  • Psychotherapy
  • Antidepressants may be prescribed by your GP to help relieve symptoms
  • Light therapy
  • Vitamin D

Getting Support

Wellbeing and Student Support are available for students at the University of Warwick:

Medical support can be obtained through your GP.

Useful sources for information on SAD:
Self-help References:
  • Winter Blues: Everything You Need to Know to Beat Seasonal Affective Disorder. Norman E. Rosenthal The Guildford Press
  • Seasonal Affective Disorder for Dummies. Laura L. Smith and Charles H. Elliot (2007). Wiley Publishing Inc.
  • The Light of Day: A Mindbody Approach to Overcoming Seasonal Affective Disorder. Lawrence Hayes (2008) Trafford Publishing
  • Help is on the Way: Saying Farewell to Seasonal Affective Disorder. Raymond Bloom (2012) Ellipsis Books
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