Video: What is Seasonal Affective Disorder? (SAD)
This video may take a few moments to load.
(NHS 24, UK 2022)
Low or no data? Visit zero.govt.nz, scroll down the page then click on our logo to return to our site and browse for free.
This video may take a few moments to load.
(NHS 24, UK 2022)
Researchers think that a lack of sunlight might stop a part of the brain called the hypothalamus from working properly. This affects:
It's possible that some people are more vulnerable to SAD because of genes inherited from their whānau/family.
You may have SAD if during the winter months you:
If you have symptoms of SAD, it’s important to see your doctor before they get worse. Your doctor will ask you about your mood, sleep, eating, thoughts you’ve been having and whether you’ve had depression before. They may also recommend some blood tests. Because it is common for people who have had depression to get it again, it can take a few years for you and your doctor to work out if your symptoms are seasonal.
Your doctor will probably recommend antidepressant medication, psychological therapy or a combination of both. If your symptoms are more severe, they may also recommend light therapy.
Cognitive Behavioural Therapy (CBT) is a type of talking therapy that helps you to use activities and thoughts to improve your mood. Research shows that CBT is an effective treatment for SAD. Ask your doctor to refer you to a psychologist or counsellor who is trained in the use of this effective therapy. Most New Zealand trained clinical psychologists are trained in CBT. You can search for a clinical psychologist(external link) near you.
Otherwise, you can use an online therapy programme like Beating the Blues or Just a Thought to beat SAD.
In light therapy, you sit by a special lamp called a light box for about 30 minutes to an hour each morning, shortly after waking, so that you're exposed to bright light. Light therapy mimics natural outdoor light and appears to cause a change in brain chemicals linked to mood.
The recommended light boxes have filters that remove harmful ultraviolet (UV) rays, so there's no risk of skin or eye damage for most people. Research shows that light therapy is an effective treatment for SAD.
When light therapy has been found to help, most people notice an improvement in their symptoms within a week or so. Ask your doctor about whether light therapy is an option for you and how to get a light box.
Another type of light therapy is called dawn stimulation. It involves a special kind of light that gradually brightens your room, mimicking the light at sunrise. This has also been found to work well for SAD.
Antidepressants are often prescribed to treat depression, and they may also sometimes be used to treat severe cases of SAD.
There are many different types of antidepressants, but the selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine, citalopram, escitalopram or paroxetine are preferred for treating SAD. They increase the level of the hormone serotonin in your brain, which can help lift your mood.
If you're prescribed antidepressants, you should be aware that:
Once you know that your symptoms of depression follow a seasonal pattern, you can use medication to prevent further bouts in winter. Research shows that the medication Bupropion is the most effective for preventing SAD before it kicks in during the winter months. Read more about antidepressants.
Read more tips for managing SAD.
In the summer months, develop habits that you can carry over even in winter that make sure you spend time outside in daylight each day, particularly in the first half of the day. This could be to exercise outside when you get up in the morning, walk part of the way to work, go for a walk at lunchtime or have lunch outside wherever possible. On the weekend, keep up a regular outdoor activity, such as sport, gardening, going for a bike ride with a friend or playing in the park with your children. Bupropion is the only medication found to reliably prevent SAD.
Depression self-test(external link) The Low Down, NZ
Seasonal affective disorder (SAD)(external link) NHS Choices, UK, 2015
Seasonal affective disorder(external link) Patient Info, UK, 2016
Tell me everything I need to know about seasonal affective disorder (SAD)(external link) PsyCom, US, 2021
Beating the blues(external link) Online CBT programme, NZ
Small Steps(external link) Online resources for helping you to manage stress, calm your mind and lift your mood, NZ
It can take several years to diagnose seasonal affective disorder (SAD). However, as it is considered a type of recurring major depression with a seasonal pattern, this does not affect treatment.
According to the Diagnostic and Statistical Manual of Mental Disorders DSM-V, the criteria for Major Depressive Disorder with a seasonal pattern include having depression that begins and ends during a specific season every year (with full remittance during other seasons) for at least two years and having more seasons of depression than seasons without depression over a lifetime. Seasonal pattern disorders occur most frequently in winter although they can also occur in summer.
The patient should be assessed for other psychological conditions, including:
The Seasonal Pattern Assessment Questionnaire(external link) is a commonly used assessment tool for SAD. While it’s not sensitive enough for diagnosis on its own, it is seen as valid as a screening tool. Scoring information(external link) is available but note that there is an error – the 4th bullet point says “A GSS of 11 or higher and a score on Q.11 of moderate or greater is indicative of SAD” when it should say “A GSS of 11 or higher and a score on Q.17 of moderate or greater is indicative of SAD” as it mentions Q17 in the previous bullet point.
SSRIs are particularly effective for women with depression.
Credits: Healthify editorial team. Healthify is brought to you by Health Navigator Charitable Trust.
Reviewed by: Kris Garstang, Clinical Psychologist, Life Mind Psychology
Page last updated: