Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

beginning of content

Seasonal affective disorder (SAD)

7-minute read

If you need to talk to someone about your mental health, call Beyond Blue on 1300 22 4636.

Key facts

  • Seasonal affective disorder is a type of depression that comes at certain times of the year, usually in winter.
  • Seasonal affective disorder is very rare in Australia.
  • Symptoms can include lack of energy, overeating and sleeping too much.
  • It is thought to be caused by the changes in light exposure in different seasons.
  • Treatment includes antidepressant medicines, light therapy, vitamin D and counselling.

What is seasonal affective disorder?

Seasonal affective disorder is a type of depression that comes and goes according to the season. People with seasonal affective disorder experience symptoms of depression or mania at roughly the same time each year.

Seasonal affective disorder usually develops in autumn and winter and then disappears in spring and summer. In some people, the symptoms develop in spring and early summer.

What are the symptoms of seasonal affective disorder?

Symptoms of seasonal affective disorder in winter include:

  • low mood
  • sleeping too much
  • lack of energy and fatigue
  • craving carbohydrates and sugary foods
  • gaining weight
  • losing interest in normal activities

Symptoms of seasonal affective disorder in summer include:

Symptoms usually start out mild and get worse as the season progresses. When the season changes, people normally become well again.

People with a mental health disorder might find that their symptoms change at different times of the year. For example, some people with depression or bipolar disorder find that their symptoms of depression get worse in different seasons.

CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.

What causes seasonal affective disorder?

The cause of seasonal affective disorder is not clear. It is thought to be caused by changes in light exposure, which lead to changes to the body’s circadian rhythms (its 'body clock'). At different times of the year, the body produces different amounts of melatonin and serotonin, which affect mood.

You are at higher risk of having seasonal affective disorder if you:

  • are female
  • are young
  • live further from the equator
  • have a family history of seasonal affective disorder or depression

When should I see my doctor?

Seasonal affective disorder is very rare in Australia. If you have symptoms that don’t go away and are affecting your everyday life, it’s important to see a doctor. They can help you build a mental health care plan and refer you to a mental health professional if needed.

ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.

How is seasonal affective disorder diagnosed?

Seasonal affective disorder can be difficult to diagnose, as it can be confused with other mental health conditions. You may not be diagnosed until you have experienced the same symptoms during winter for at least 2 years.

Your doctor ask questions about how you feel and how long you have been feeling that way. Your doctor may refer you for tests to rule out medical conditions that could be causing your symptoms.

How is seasonal affective disorder treated?

The first step of treating seasonal affective disorder is to talk to a doctor or a mental health professional.

Once you are diagnosed, treatment options can include:

It’s a good idea to make your house as light as possible during autumn and winter, and to sit close to windows as often as you can.

Getting outside as much as possible and exercising regularly can also help lift your mood and reduce symptoms of seasonal affective disorder.

Resources and support

There are Australian organisations that offer help and resources for people with depression.

If you need to speak with someone, you can call theses helplines for general mental health support.

  • healthdirect helpline - 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available 24 hours a day, 7 days a week.
  • Sane — talk to a mental health professional on 1800 187 263
  • Beyond Blue — 1300 22 4636 for phone counselling or chat online
  • Suicide Call Back Service (for anyone thinking about suicide) — 1300 659 467
  • Lifeline (for anyone having a personal crisis) — call 13 11 14 or chat online

Do you prefer to read in languages other than English?

Looking for information for Aboriginal and/or Torres Strait Islander people?

  • Yarn Safe and Wellmob have mental health information and resources for Aboriginal and/or Torres Strait Islander people.


Beyond blue (A guide to what works for depression in young people), Wayahead (Seasonal Affective Disorder), Beyond Blue (Types of depression)

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: February 2024

Back To Top

Need more information?

These trusted information partners have more on this topic.

Top results

Seasonal affective disorder -

Seasonal affective disorder is a type of depression striking in the autumn and winter months. Symptoms include difficulty waking up, extreme tiredness and lack of energy.

Read more on MyDoctor website

Seasonal Affective Disorder - WayAhead

Seasonal Affective Disorder, or SAD, is a mood disorder that occurs in people who display no other mental health symptoms or issues throughout the year.

Read more on WayAhead Mental Health Association NSW website

Light Therapy - BluePages

Find out if light therapy is likely to help.

Read more on e-hub Web Services - Australian National University (ANU) website

Types of depression - Beyond Blue

Depression is a serious condition that affects 1 in 7 Australians. Explore the types of depression and support available.

Read more on Beyond Blue website

Complementary therapies

The facts Many people use complementary therapies to support medical treatment. Complementary therapies are not a replacement for adequate medical tre...

Read more on SANE Australia website

Complementary Therapies - Finding North

Complementary therapies don't treat mental health conditions but are used to help improve our overall health and well-being, for example to help feel better physically and emotionally.

Read more on Finding North website

Depression and Sleep | Sleep Health Foundation

This is a fact sheet about Depression and Sleep. Depression and sleep are closely intertwined: depression can affect sleep and vice versa.

Read more on Sleep Health Foundation website

Everything you need to know about Depression | Depression

Learn more about depression, the symptoms of depression & learn how to deal with depression in our guide. Remember, you're not alone & help is available.

Read more on website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Queensland Government logo Government of South Australia, health department logo Tasmanian government logo Victorian government logo Government of Western Australia, health department logo

Healthdirect Australia acknowledges the Traditional Owners of Country throughout Australia and their continuing connection to land, sea and community. We pay our respects to the Traditional Owners and to Elders both past and present.