People can get sad about summer coming to an end, with the return of school, the end of beach days and long summer evenings. But, what happens when this sadness turns to something more? ‘Seasonal affective disorder’ (SAD), also known as ‘winter depression’ affects approximately 1 in 15 people according to the NHS.

There are two types of SAD. One being a milder version called ‘sub-syndromal SAD’, which is also known as the ‘winter blues’. However, for those with full-blown SAD, it can make daily life almost impossible through winter without treatment – mainly December through to February. SAD is a type of depression that comes and goes with changes in season. The symptoms of SAD may begin in autumn, when the days start getting shorter and the nights longer. It is not uncommon for it to improve and completely disappear during spring and summer. However depression returns during the colder months each year.

The symptoms of SAD are relatively similar to typical depression. The signs to look out for may include:

• A persistent low mood
• Not finding pleasure in activities that were once enjoyable
• Irritability and/or frustration
• Feelings of guilt and worthlessness
• Lack of energy, feeling extremely tired all day
• Sleeping too much and finding it difficult to get out of bed in the morning
• Changes in appetite, not having an appetite or overeating
• Thoughts of self-harm or suicide

If you are experiencing any of the above symptoms and have had them for longer than two weeks, visit your GP. If you experience the symptoms all year round and it is not affected by the seasonal changes, you may be suffering from depression, so a trip to see a mental health professional would be worth it.

The precise causes of SAD are unknown, however there are a few things which are assumed to be linked (according to the NHS). The main theory is that lack of sunshine may stop a part of the brain (hypothalamus) from functioning properly. The hypothalamus is responsible for a range of different things including hormones which make you feel sleepy. In people with SAD, more of this hormone may be released, which makes them feel more tired than usual. Another hormone which can be impacted by that particular part of the brain is responsible for emotions, appetite and sleep – meaning all of these things can be affected from simply lack of sunlight. Finally, SAD may be passed down in the genes.

So how is it treated?

Seasonal affective disorder can be treated in a number of ways ranging from lifestyle changes including trying to get as much natural light as possible, exercising regularly, eating well and managing stress. Another form of treatment is light therapy. Light therapy is a lamp which exposes you to artificial sunlight, which in turn should trigger the part of the brain affected to improve. Finally, other forms include types of therapies such as CBT (cognitive behavioural therapy) or medication to help with depression.

For more information, you can visit the Seasonal Affective Disorder Association.