For some people, low mood arrives like clockwork with the shorter, darker days — and lifts again in spring. This is seasonal affective disorder (SAD), a recognised pattern of depression tied to the seasons. It’s real, and it’s treatable.
What SAD is
SAD isn’t a separate illness but a seasonal pattern of depression — most commonly, depressive episodes that begin in autumn or winter and ease in spring and summer. A smaller number of people experience the reverse, with symptoms in the warmer months. In Australia, with milder winters than the Northern Hemisphere, SAD is less common than in colder climates, but it does affect people here — particularly in the southern states.
Signs of winter-pattern SAD
Alongside the usual symptoms of depression, winter SAD often has a distinctive flavour:
- Low mood and loss of interest that track with the season
- Low energy and sleeping more than usual
- Increased appetite, cravings for carbohydrates, weight gain
- Difficulty concentrating
- Social withdrawal — “hibernating”
Why it happens
The leading explanation involves reduced daylight affecting the body clock and the brain chemicals that regulate mood and sleep. Less light in the mornings and evenings appears to disrupt circadian rhythms in susceptible people.
Treatment
SAD responds to treatment, and there are some season-specific options:
- Light therapy — daily use of a specially designed bright light box has good evidence for winter-pattern SAD.
- Getting outdoor light — especially in the morning.
- Psychological therapy — CBT adapted for SAD helps.
- Medication — antidepressants may be appropriate, as for other depression, guided by your doctor.
When to seek help
If your mood reliably drops with the seasons and affects your life, you don’t have to just wait it out. Try our depression self-check, read about our depression care, or book an appointment with a referral.
This article is general information, not medical advice. In a crisis, call Lifeline on 13 11 14 or 000.