Seasonal affective disorder (SAD) is a type of depression that follows a seasonal pattern — most commonly occurring in autumn and winter when daylight hours shorten, then lifting in spring. It affects around 2 million people in the UK and a further 10% experience a milder form. It is a real, recognised condition — not just "winter blues" — and responds well to several specific treatments.
See therapies that may helpSAD is classified as a subtype of recurrent depressive disorder with a seasonal pattern. For most people, symptoms begin in October or November, worsen through December and January, and lift naturally in spring. A smaller number experience summer SAD — a less common pattern where symptoms occur in the warmer months.
The cause is not fully understood, but the leading theory involves reduced sunlight affecting the hypothalamus, leading to disrupted production of melatonin (the sleep hormone) and serotonin (a neurotransmitter that affects mood, appetite and sleep). Circadian rhythm disruption also plays a role.
SAD is more than simply disliking winter. When it is clinical SAD, it involves the full symptom picture of depression, recurring predictably each year and significantly affecting quality of life.
SAD symptoms typically mirror those of depression but with some distinctive features:
SAD has several treatment options, often used in combination:
Talking therapy — CBT, counselling or mindfulness-based approaches — can help address both the acute seasonal episodes and the underlying vulnerability to SAD.
If you experience significant mood changes that predictably worsen each winter and improve in spring, and this has happened for at least two consecutive years, it is worth speaking to a GP or therapist. SAD is well recognised and there are effective treatments.
A light therapy lamp can be purchased without a prescription and is a reasonable first step to try. Your GP can assess whether antidepressants are appropriate and can refer to psychological therapies.
Showing 8 therapies linked to Seasonal affective disorder (SAD).
| Therapy | Evidence | Notes |
|---|---|---|
| Cognitive Behavioural Therapist |
strong
|
CBT helps you challenge the low mood and withdrawal that set in over winter and rebuild activity as daylight fades. |
| Mindfulness Practitioner |
strong
|
Mindfulness practice can ease the rumination and flat mood of darker months, helping you notice seasonal shifts without being overwhelmed. |
| Psychotherapist |
strong
|
Talking therapy offers space to explore how shortening days affect your mood and to develop coping strategies for the winter slump. |
| EMDR Practitioner |
moderate
|
EMDR may help where past difficult experiences feed the winter low, though for SAD it is best used alongside established treatments. |
| EFT Practitioner |
moderate
|
EFT's tapping is used to ease seasonal low mood, but evidence is limited and it should support, not replace, proper care for SAD. |
| Herbal Medicine Practitioner |
moderate
|
Some herbal remedies are used for winter low mood, but evidence is limited and they are no substitute for appropriate care for SAD. |
| Hypnotherapist |
moderate
|
Hypnotherapy is offered to support relaxation and mood through the darker months, as a complement to recognised treatments for SAD. |
| Yoga Therapist |
moderate
|
Yoga therapy may lift energy and mood during winter through movement and breathwork, alongside proven treatments for SAD. |
SAD is a clinical condition involving the full symptom picture of depression recurring predictably each winter and lifting in spring. It is distinct from simply finding winter difficult or preferring summer. If low mood, increased sleep, carbohydrate cravings and withdrawal are significantly affecting your life each winter and have done for at least two years, SAD is worth discussing with a GP.
Yes — light therapy has good evidence for SAD and is recommended by NICE as a treatment option. Around 50–80% of people with SAD respond to light therapy. The key is using a lamp with a minimum 10,000 lux rating for around 30 minutes each morning, ideally within an hour of waking.
Yes, though it is much less common. Summer SAD typically involves insomnia, reduced appetite, weight loss, agitation and anxiety — a different profile from the more common winter SAD. It is thought to be triggered by heat and humidity rather than light changes.
SAD is a subtype of recurrent depression with a seasonal specifier. The key distinguishing features are the predictable seasonal pattern, the tendency towards increased rather than decreased sleep, and increased appetite particularly for carbohydrates. These features mean the treatment approach is somewhat distinct from non-seasonal depression.
Not necessarily. With appropriate treatment and management — including light therapy, maintaining activity through winter, and therapy — many people reduce the severity of seasonal episodes significantly. Understanding and preparing for the seasonal pattern, rather than being caught off guard each year, makes a meaningful difference.