UK charities say they are “hugely thankful” to Bruce Willis for publicly sharing his diagnosis of frontotemporal dementia, as it will help raise awareness of the condition.

The announcement by the 67-year-old Hollywood actor’s family will help “shine a light” on the disease, also known as FTD, and “encourage others to seek advice”, the charities said.

Last year Willis’s family revealed he had been diagnosed with the cognitive condition aphasia, and would be stepping back from his acting career.

In a post shared on Instagram on Thursday, his daughter Rumer offered an update on her father’s health, confirming his condition had “progressed” and he had been given the “more specific” diagnosis of FTD.

In a statement to the PA news agency, Alzheimer’s Society chief executive Kate Lee said: “We’re sending our thoughts to Bruce Willis and his family following their announcement that Bruce is living with frontotemporal dementia.

“Speaking publicly about his diagnosis will help so much to shine further light on the condition, for which we are hugely thankful.”

A spokesperson for Dementia UK said: “We’re sorry to hear that Bruce has been diagnosed with frontotemporal dementia.

“By choosing to speak publicly about his diagnosis, more awareness can be raised about FTD and hopefully it will encourage others to seek advice if they are experiencing concerns about their brain health.”

FTD is an umbrella term for a group of dementias that mainly affect the frontal and temporal lobes of the brain, which are responsible for such things as personality, behaviour, language and speech, according to Dementia UK.

It is caused by an “abnormal build-up of proteins within the brain” which damages the cells, although the reason this occurs is not known.

Willis’s family expressed their “deepest gratitude” for the “outpouring of love” they had received since the announcement about his aphasia diagnosis.

His daughter Rumer, who Willis shares with his former partner, actress Demi Moore, wrote: “Our family wanted to start by expressing our deepest gratitude for the incredible outpouring of love, support and wonderful stories we have all received since sharing Bruce’s original diagnosis.

“In the spirit of that, we wanted to give you an update about our beloved husband, father and friend since we now have a deeper understanding of what he is experiencing.

“Since we announced Bruce’s diagnosis of aphasia in spring 2022, Bruce’s condition has progressed and we now have a more specific diagnosis: frontotemporal dementia.

“Unfortunately, challenges with communication are just one symptom of the disease Bruce faces. While this is painful, it is a relief to finally have a clear diagnosis.”

According to the NHS, frontotemporal dementia is an “uncommon” form of the disease, and mostly affects people aged between 45 and 65.

The family statement added: “Bruce always believed in using his voice in the world to help others, and to raise awareness about important issues both publicly and privately.

“We know in our hearts that – if he could today – he would want to respond by bringing global attention and a connectedness with those who are also dealing with this debilitating disease and how it impacts so many individuals and their families.”

The statement was signed by members of Willis’s family, including his wife Emma Heming, former wife Moore and his daughters.

Willis has starred in hit films including the Die Hard series, Pulp Fiction, Armageddon, Moonrise Kingdom, 12 Monkeys and Looper.

He has five daughters, sharing his three eldest – Rumer, Scout and Tallulah – with Moore who he married in 1987.

Despite separating in 2000, the pair remain on amicable terms. Willis went on to marry actress Heming in 2009.

They have two daughters, Mabel and Evelyn.