Seasonal affective disorder (SAD), also called major depressive disorder with seasonal pattern, is a type of depressive disorder related to the change in seasons. It is common to feel down or low over the winter as it gets colder and darker. However, when this change in mood starts to impair your daily functioning and overall wellbeing this may be SAD.
SAD is characterised by a pattern of depressive symptoms which start and end around the same time each year. Symptoms tend to last for 4 to 5 months over the winter. In New Zealand this is usually between May and September. Some people experience the opposite pattern, with depression over the summer months, but this is rare.
It has been proposed that SAD is related to changes in sunlight and the effect this has on chemicals within the brain. The neurochemicals proposed to be involved in SAD are serotonin, which is involved in mood, sleep and appetite, and melatonin, which is involved in mood and sleep. Less sunlight over the winter means we get less vitamin D and there is a decrease in serotonin activity leading to low mood. Less sunlight also means an increase in melatonin production which makes us feel more tired. The changes in the levels of these neurochemicals has an impact on the body’s internal clock.
The role of sunlight in SAD is supported by differences in the percentage of the population who have SAD in different places around the world. SAD is more common in areas further from the equator which get less sunlight over the winter months. SAD is also more common in those with a family history of depression, or a personal history of depression or bipolar disorder.
- Feeling sad or low nearly all day every day over the winter season.
- Loss of interest in things you used to enjoy
- Fatigue and low energy
- Feeling worthless, hopeless.
- Feeling irritable, anxious.
- Difficulty concentrating
- Becoming isolated, withdrawing from family/ friends.
- Changes in sleep - sleeping too much or too little.
- Changes in appetite - eating too much or too little.
- Changes in weight - losing or gaining weight.
- Thoughts of harming yourself
- Thoughts of suicide or death
There are effective treatments available for SAD. Treatment usually involves a combination of psychological therapy (talk therapy), medication, and light therapy.
Psychological Therapy:
Psychological therapy or counselling can benefit those with SAD.
Cognitive behavioural therapy (CBT) is a structured form of talk therapy which has been shown to help those with SAD. CBT explores how our beliefs, thoughts, and actions are related and impact each other. Through CBT those with SAD learn how to identify and change negative thoughts and behaviours, learn coping skills, and find ways to improve mood and reduce stress.
Medication:
Antidepressants, such as selective serotonin reuptake inhibitors (SSRIs), may be prescribed to treat SAD. Ideally medication is used in combination with talk therapy.
Light Therapy:
Light therapy has been shown to reduce the symptoms of SAD and improve mood. The treatment involves sitting by a light therapy box or special lamp for 30 to 60 minutes each morning over the winter months. The light emitted is 10 to 20 times more intense than normal indoor lighting to mimic natural sunlight. Light therapy changes the levels of certain neurochemicals in the brain, such as serotonin and melatonin, to improve mood and sleep and reduce SAD symptoms.
Other ways to manage SAD and improve your mood over winter:
- Get lots of sunlight - Try to spend time outside each day, ideally within the first few hours of waking up. When you are inside, try to sit by the windows and let as much sunlight into the room as possible.
- Prepare for the winter months - SAD symptoms follow a predictable seasonal pattern meaning you know roughly when symptoms will start and so you can prepare. It might help to plan therapy appointments over the winter and make a list of things you can do over the winter to improve your mood.
- To improve your general wellbeing over the winter months… - Keep up regular exercise and physical activity, maintain a regular sleep schedule, eat a healthy diet, spend time outside, and stay connected with family and friends.
‘Beating the Blues’ is an online cognitive behavioural therapy (CBT) program for New Zealanders experiencing depression and/or anxiety. The program contains 8 weekly 50 minute sessions which can be completed at anytime. These session aim to help you better understand depression and anxiety, change negative thinking patterns, learn coping strategies, and improve your mental health.
Take a look at the website for more detailed information on the program.
Depression NZ provides information on depression and anxiety to help you recognise the symptoms and develop a better understanding of the conditions. The website outlines how to access help, how to support others, and provides stories from those with lived experience.
The information about depression on depression.org.nz is about more general depression but is still relevant and helpful for those with SAD.
This video provides an overview of the symptoms of SAD and some treatment and prevention strategies.
Note: The prevalence rates given in this video are for Canada. The general information on SAD is still relevant to other countries.
This TED-Ed ‘What is depression?’ video provides an easy to understand overview of the symptoms of depression, treatment options, and how to help if someone you know is suffering with depression.