Seasonal Affective Disorder (SAD): Care Staff Guide

Seasonal affective disorder, often shortened to SAD, is a type of depression that follows a seasonal pattern. For most people it begins in the autumn or winter and eases in the spring and summer. It is easy to dismiss as "winter blues", but for some people it is a serious condition that affects their mood, sleep, appetite and ability to cope. This guide, based on NHS information reviewed in December 2025, explains the symptoms, how SAD is treated and what care and support staff can do to help. It should be read alongside our guide to depression screening for older adults in care homes.

What is seasonal affective disorder?

The NHS describes SAD as depression with a seasonal pattern, most often starting in autumn or winter and lifting in summer. Less commonly, some people become depressed in the summer instead. The exact cause is not explained on the NHS pages, so staff should avoid assuming a single reason for a person's low mood.

A diagnosis usually depends on a pattern repeating over time. The NHS says a diagnosis usually needs the same pattern for at least two years, which is why a GP will ask about previous winters and summers.

Symptoms to look out for

According to the NHS, symptoms of SAD can include:

• feeling down for much of the day, and losing interest in usual pleasures
• feelings of guilt, hopelessness or low self-worth
• restlessness or irritability
• trouble concentrating
• a bigger appetite and overeating
• extra tiredness and sleeping more than usual
• thoughts of suicide or self-harm

The NHS also notes that some people feel an energy surge in early spring or summer. That change is worth noticing and recording, because it can be part of the seasonal pattern. If you support someone whose mood seems to swing in a way that goes beyond the seasons, our guide to bipolar disorder for care staff explains why a clinician should assess it.

Why this matters in care settings

People who receive care often spend more time indoors, may have mobility problems and may have fewer chances to go outside in winter. Staff are often the people who see a person day in and day out, so you may be the first to notice a change in mood, appetite, sleep or interest in activities as the weather turns. This is a practical observation rather than a clinical finding, and every person is different, but it is a good reason to pay particular attention to wellbeing in the darker months.

How SAD is treated

The NHS lists several treatment options. A GP or mental health professional will advise on what is suitable for the individual.

• Talking therapy: cognitive behavioural therapy (CBT) and other talking therapies may be offered.
• Medicines: antidepressants may be prescribed.
• Light therapy: this uses a bright lamp, often called a SAD lamp or light box, to mimic winter daylight. The NHS says it does not usually offer light therapy because the evidence of effectiveness is limited, although many people find it helpful. A GP should be consulted first, because a lamp may not suit some eye conditions or some medicines that increase light sensitivity. If a lamp is bought, the NHS suggests one rated at around 10,000 lux, free of UV and carrying a UKCA or CE mark.

Many people need treatment each winter to stop symptoms coming back, so staff should not assume that a person who has recovered is "cured" for good. Planning ahead for the autumn can make a real difference.

Practical support for care staff

Alongside treatment, the NHS suggests a number of self-help measures. Care staff can support people to follow them where they choose to.

• Get as much daylight as possible. Where it is safe, encourage time outdoors each day, and consider seating arrangements that make the most of natural light.
• Support regular exercise and social contact. Keep up usual activities and contact with friends and family.
• Keep sleep routines steady. A consistent bedtime and wake time helps, and so does avoiding screens right before bed.
• Be mindful of alcohol and drugs. The NHS advises limiting alcohol and avoiding illegal drugs.
• Record changes. Note mood, appetite, sleep and participation, and share them with the person's GP or care team.

When to get help

The NHS advises seeing a GP if you think you may have SAD, or if you have been diagnosed and treatment is not helping. Adults aged 18 or over can also self-refer to NHS talking therapies without a GP referral, and in some areas the age is 16. Under-18s should look at NHS children and young people's mental health support.

If a person talks about suicide or self-harm, take it seriously, follow your organisation's procedures and get urgent help straight away. Our guide to suicide and self-harm awareness for care staff explains how to respond. In an emergency, call 999.

Frequently asked questions

Is SAD just feeling low in winter?

No. Feeling a bit flat in winter is common, but SAD is a form of depression that affects daily life and needs support.

Can SAD happen in summer?

Yes, although it is less common. The NHS notes that some people have depression that starts in the summer.

Are light boxes safe for everyone?

Not necessarily. The NHS advises speaking to a GP first, as light therapy may not suit some eye conditions or some medicines.

How can staff keep learning?

Explore the health and social care learning available through Learnsignal CPD to build your confidence in recognising and responding to mental health needs.

This article is general information for care staff, based on NHS information, and does not replace the advice of a person's own clinicians. If you are worried about someone's health right now, contact their GP, NHS 111 or, in an emergency, call 999.