The Carter family has said that former First Lady Rosalynn Carter has dementia, The Carter Centre announced on Tuesday.

“She continues to live happily at home with her husband, enjoying spring in Plains and visits with loved ones,” said a statement from the think tank founded by former president Jimmy Carter, 98, and his wife.

The centre noted that Mrs Carter, 95, has been a leading mental health advocate for much of her life, working to improve access to care and decrease stigma about mental illness.

The family says it is sharing the news hoping to prompt conversations at kitchen tables and in doctor’s offices that could help people and their families get the support they need, the statement said.

Married nearly 77 years, the Carter are the longest-married first couple in US history. They were married on July 7, 1946.

“Mrs Carter often noted that there are only four kinds of people in this world: those who have been caregivers; those who are currently caregivers, those who will be caregivers, and those who will need caregivers,” the centre’s statement reads.

“The universality of caregiving is clear in our family, and we are experiencing the joy and the challenges of this journey.”

“We do not expect to comment further and ask for understanding for our family and for everyone across the country serving in a caregiver role,” the statement said.

The Carters have been visiting only with family and close friends since the former president’s announcement in February that he would forgo further medical intervention after a series of short hospital stays.

The family has not disclosed any specific diagnosis for either the former president or the former first lady.

The Carters have described themselves as “full partners” throughout his political career and their long public life that followed.

Rosalynn Carter campaigned vigorously for her husband in his bids for Georgia governor and the presidency. She used her platform to prioritise mental health awareness, working to address the stigma attached to the condition.

That emphasis became part of The Carter Center’s expansive public health platforms.

Eleanor Rosalynn Smith was born in Plains, Georgia on August 18, 1927. It was Jimmy Carter’s mother, a nurse, who delivered her in her family’s home.

Lillian Carter brought her young son back a few days later to visit, allowing the future president and first lady to meet as preschooler and newborn.

Jimmy Carter enjoyed telling everyone that his wife was “more political” than he was, a point she did not protest.

“I would be out there campaigning right now if Jimmy would run again,” she wrote just a few years after his defeat. “I miss the world of politics.”