People should look out for signs of depression and dementia among older family members and friends over Christmas, a health chief has said.
Professor Alistair Burns, NHS England's national clinical director for dementia and older people's mental health, said problems that may have previously been hidden can come to the surface or be easier to spot as friends and families get together over the festive season.
Depression should not be written off as inevitable in old age and can be treated effectively, while emotional changes can also be the first indication that someone has dementia, he said.
Anyone who is concerned about a friend or loved one should listen carefully and sympathetically to their concerns, and encourage them to seek help and get checked out by their GP, who can provide reassurance and ensure they get the treatment and support they need.
Prof Burns said: "Dementia is an insidious disease that develops slowly and may go unnoticed in people we see every day.
"As families and friends get together over Christmas, there is an opportunity to spot warning signs that may have been missed.
"There are lots of reasons why people might be forgetful or absent-minded at such a busy time of the year but it could also be the sign that something can be wrong.
"Getting a diagnosis - whether it is for depression or dementia - is the first step in accessing the best help and support."
It is estimated that around 676,000 people have dementia in England and one in three of us will care for someone with the disease at some point in our lives.
While it mainly affects people over 65, for some dementia can develop earlier, presenting different issues for the person affected, their carer and their family.
The condition costs the country £26 billion a year.
Prof Burns went on: "We often put mood changes in loved ones down to normal ageing, more so for people in long-term relationships.
"Symptoms often develop very slowly so it is easy to regard them as being a normal part of ageing, but this is not always the case.
"A lot of people in long-term relationships might think that their partners are simply in a mood.
"The important thing is to look for changes in normal behaviour. If your partner is down and forgetful or feels they may not be able to cope with the thought of Christmas, it would be worth getting them checked out by their GP."
Awareness-raising by NHS England has helped to diagnose 175,000 more people with dementia over the last few years, while the forthcoming NHS long-term plan will set out increased support for patients and their families.
Prof Burns said there is a range of NHS services to help people with dementia along with support for their family and carers.
As well as treatment from GPs and hospitals, other types of healthcare include community mental health nurses, physiotherapy, hearing care, optometry, foot care, speech and language therapy, and mobility specialists.