Seasonal affective disorder (SAD)
Some of us notice that we
don't feel so good in the winter months, particularly if we live
somewhere where the climate changes a lot and it is dark during the
This feeling can interfere with your life - some people say that
it feels "like hibernation".
This is what we call
Seasonal Affective Disorder (SAD). The term "Winter Depression" and
"Winter Blues" has also been used to describe this.
What is seasonal affective
SAD has a lot in common
with depression. Have a look at our general leaflet on
reading this leaflet.
The main symptoms of
SAD are similar to those of depression, but happen in the
- low mood
- lack of interest and
enjoyment in life
Often also these symptoms occur also:
- low energy
- being less sociable
- being less irritable
- less interest in sex.
Common symptoms of SAD which
are different from those in most depression
- sleeping more
- eating more.
If you have SAD, you
may find it hard to wake up on a winter's morning and can often
feel sleepy during the day. You may crave chocolate and high
carbohydrate foods, such as white bread or sugary foods. You might
find you put weight on.
SAD gets better in the
spring. Indeed, around a third of people with SAD have a time when
they feel more energetic than usual during the spring and
Who is affected by
Like other types of
depression, SAD is most common in women during the years when they
can have children. It is about three times more common in
women than it is in men. SAD is less common in children and
in older adults, affecting men and women equally.
How common is
Many of us will feel
different in the winter with symptoms of feeling slightly
tired, sleeping a bit more and perhaps gaining some weight.
It is a bit like hibernation in animals. If your symptoms are bad
enough to interfere with your life, you may well have SAD. In
the UK, about 3 people in every 100 have significant winter
We do not fully understand
what causes SAD, but the reduced amount of light in the winter
seems to be important. It is more common where it is dark in the
winter. There has been a lot of research exploring how daylight can
influence appetite, wakefulness and mood.
However, people living in
very northern areas do not appear to suffer more SAD than people
living further south, so other factors may be important. Also, some
people report that they feel depressed in the summer instead.
SAD can be treated in the
same way as depression. Treatment usually includes self-help and
lifestyle changes, talking therapies and antidepressant medication.
Light box treatments are also popular and have some evidence.
Some symptoms of SAD can
create extra problems which make you feel even worse – 'vicious
- If it is dark and you feel tired all the time, you will
probably do less – and this can make SAD worse. Try to get as much
natural sunlight as possible. Take a walk during daylight hours or
carry on any exercise you would normally do. Remind yourself that
days will get longer again in the spring.
- If you are eating more, you may put on too much weight which
makes you feel worse. Remind yourself that most people put on
weight in autumn and early winter.
- Sleepiness, lack of motivation and irritability can all cause
problems at home, with your friends, and at
work. The feelings of not getting things done can make you
feel stressed. Tell your family and friends so that they can
understand what is happening and be supportive.
The idea is to try
to provide extra light and to make up for the shortage of
daylight in winter. A "light box" is used. Its light
is like sunlight, but without the ultraviolet rays, so it
is not harmful to the skin or the eyes. It may help tell the brain
to make less of a hormone, melatonin.
A light box is usually
used for 30 minutes to an hour each day. It is most helpful if
you use it at breakfast time. Light therapy works quite
quickly. If it is going to help, most people will notice some
improvement in the first week.
side-effects are usually mild. They include headache, nausea
or blurred vision. It is usually best not to use a light box
after 5.00 pm because you may then find it hard to get to
alarm clocks are also used. These come on dimly about
an hour before waking up time and gradually get brighter. They
can be helpful if you find it hard to wake up on winter
be helpful in SAD. Any medication which would make people
more tired or sleepy should be avoided, and so SSRI antidepressants
are usually used (more details in our leaflet on antidepressants).
The best evidence is for the use of sertraline, citalopram or
fluoxetine. In SAD, it is usual to start antidepressants in
the autumn and stop them in the spring. A recent review of the
evidence did not find a large effect, but you ask your doctor.
Cognitive behavioural therapy (CBT)
There is some evidence that CBT can help winter depression and
may prevent it coming back in future winters. CBT is a treatment
for anxiety and depression in general. You have weekly sessions
with a therapist and do some homework, like keeping a diary. Have a
look at our leaflet on
What is the best
For mild symptoms, the
self-help measures described in this leaflet will usually
If your symptoms are worse, the first choice is usually between
a light box and antidepressants. The choice will often depend on
what is available, what is convenient and what you prefer.
There are numerous companies selling
light boxes, and some will offer a trial-and-return so you can
return it if it is not helpful. Search on the internet or contact
Anonymous (2009) Management of seasonal affective disorder.
Drugs and Therapeutic Bulletin, 47, 128-132.
Golden, BN et al (2005) The efficacy of light
therapy in the treatment of mood disorders: a review and
meta-analysis of the evidence. American Journal of
Psychiatry, 162, 656-662.
Eagles, JM (2009) Light therapy and seasonal
affective disorder. Psychiatry, 8, 125-129.
Thaler K, Delivuk M, Chapman A, Gaynes BN, Kaminski A,
Gartlehner G. Second-generation antidepressants for seasonal
affective disorder. Cochrane Database of Systematic Reviews 2011,
Johnsen et al.: Is there a negative impact on mental distress
and sleeping problems in the sub-arctic? Findings from the
cross-sectional Tromsø Study. BMC Psychiatry 2012
Produced by the Royal
College of Psychiatrists' Public Engagement Editorial Board.
Series editor: Dr Philip Timms
Original author: Professor John Eagles
Reviewed by Dr Wojtek Wojcik and Dr Robin
Service user/carer input: Depression Alliance
Illustration: Lo Cole: www.locole.co.uk
This leaflet reflects the best available evidence available at
the time of writing.
© April 2015. Due for review: April 2018. Royal
College of Psychiatrists.
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