Seasonal Affective Disorder

Seasonal affective disorder (SAD) is a form of depression that's related to the change of season from summer to winter, and which affects people through the winter months.

For some, SAD may be mild and doesn’t interfere too much with their daily functioning. But for others SAD is seriously disabling and prevents them from functioning normally without continuous medical treatment.

You may hear it called depressive disorder with seasonal pattern, and you may have even heard of people talking about the ‘winter blues’. It’s all the same thing. It is less likely to occur in New Zealand than in countries who have little sunlight in winter.

Like depression, SAD can affect how you feel and behave for weeks or months at a time. When you are depressed, your low mood lasts, affecting your sleep, energy levels, relationships, job and appetite. The difference between depression and SAD is that if you experience SAD your symptoms will appear around the end of autumn, and continue through until the days get longer and sunnier in spring.

You should not ignore SAD, as it can be effectively treated.

If you think you are experiencing SAD, talk to your doctor. Treatment may be as simple as staying out in the sun for a time each day, or it may mean being treated for depression through the winter months.

It’s important that you take SAD seriously as it can get worse and lead to other problems such as substance abuse, school or work problems, loss of interest in relationships and even suicidal thoughts.

The risk of suicide in people experiencing any form of depression is significant.

The exact cause of SAD is unknown. It may be that the drop in sunlight hours affects the body’s chemical balances and make our body clock go out of step. These changes in the brain can make some people vulnerable to SAD.

Symptoms of SAD usually build up slowly through late autumn and winter months. Symptoms are usually the same as with other forms of depression and can include:

There is no test to diagnose SAD. A diagnosis is made by your doctor based on whether you have some or all of the typical symptoms. 

For a diagnosis of SAD, the pattern of symptoms starting during autumn/early winter and reducing in spring/early summer must have occurred during at least a two-year period, with no other episodes of depression during that same timeframe.

For this reason it’s important that your doctor spends time with you to get a full understanding of the difficulties you have had, both from you and your family’s perspective.

While SAD could be responsible for the symptoms listed above, the same picture can be seen with the depressed phase of bipolar affective disorder and in some medical conditions.

This is why your doctor may do tests necessary to rule out these conditions.

Your doctor may prescribe antidepressants. Finding the right medication can be a matter of trial and error – there is no way to predict which medication will be effective and tolerated (have fewer troublesome side effects) by any one person. 

If you are breast feeding no medication is entirely safe. Before making any decisions about taking medication at this time you should talk with your doctor about the potential benefits and problems. 

If you are prescribed medication you are entitled to know:

The term complementary therapy is generally used to indicate therapies and treatments that differ from conventional western medicine and that may be used to complement and support it. 

Certain complementary therapies may enhance your life and help you to maintain wellbeing. In general, mindfulness, hypnotherapy, yoga, exercise, relaxation, massage, mirimiri and aromatherapy have all been shown to have some effect in alleviating mental distress.

It is also really important to look after your physical wellbeing. Make sure you get an annual checkup with your GP. Being in good physical health will also help your mental health.

Thanks to Janet Peters, registered psychologist, for reviewing this content. Date last reviewed: 2014.