What the NHS says about SAD in winter: self-care, light boxes and when to see a GP

On the first days of winter time the evenings close in fast. The NHS page on seasonal affective disorder (SAD) is the plain reference for what many people feel as the days shorten. This guide summarises what that page says and nothing more, because it overlaps with sleep: the NHS lists changes in sleeping patterns among the effects. We read it on 1 November 2026. For a wet-weather walking routine, our earlier guide on keeping a daylight walk when it rains goes through it.

What the page says SAD is

It calls SAD a type of depression that usually happens in the winter and goes away in the summer, and says some people have symptoms in summer instead, which is less common. The symptoms it lists include low mood, a lack of interest in things you usually enjoy, feeling guilty, hopeless or worthless, feeling restless or irritable, difficulty concentrating, eating more than usual, and being more tired and sleeping more than usual. It also lists thoughts of suicide or self-harm, and the page opens with a prompt to get urgent help in a crisis.

On the cause, it says it is not known exactly but is thought to be linked to reduced daylight in winter, which may change brain chemicals such as melatonin and serotonin that affect mood and the sleep-wake pattern.

At a glance

Light boxes

The NHS describes light therapy as using a bright light, sometimes called a SAD lamp or light box, to simulate daylight in winter. It says it is not usually available on the NHS because there is not enough evidence to tell whether it is effective, though many people find it helps. It says to speak to a GP before trying light therapy, because it might not suit people with certain eye conditions or those taking some medicines that increase sensitivity to light. If you buy one, it says to make sure it is bright enough (10,000 lux is standard), UV-free and carries a UKCA or CE mark, and to follow the manufacturer’s instructions. We make no claim for any product here.

The self-care list

Do: get as much natural daylight as you can and try to go outside in the daytime every day; get regular exercise; stay in contact with friends and family; keep up with your usual activities; and try to go to bed and wake up at the same time every day.

Don’t: drink too much alcohol or use illegal drugs, or use electronic devices such as smartphones right before going to bed.

One practical note

Going outside daily is the easiest line to lose on a wet day. This part is our note, not the NHS’s: Lumuwala and Calm Eden have the same owner, and a small umbrella that clips to a bag keeps both hands free on the walk. The Haven Umbrella folds to 40 cm and weighs about 390 g by the maker’s figures. None of this treats low mood, and an umbrella is no substitute for the care above.

In short

• The NHS says SAD is a type of depression that usually happens in winter, thought to be linked to reduced daylight.
• Its light-box advice: speak to a GP first, then look for 10,000 lux, UV-free and a UKCA or CE mark.
• See a GP if you think you might have SAD, or you can self-refer to NHS talking therapies if you are 18 or over.

Source: NHS, Seasonal affective disorder (SAD), read on 1 November 2026. The notes are our own, and this is general information, not medical advice.