Former Teen Idol & Broadway Alum David Cassidy Reveals He's Battling Dementia

Following a perplexing concert performance in Agoura Hills, CA over the weekend, former teen idol David Cassidy revealed to PEOPLE that he is battling dementia. On video shared by audience members from the recent performance, the singer is seen struggling to recall lyrics and even falling off the stage.

The 66-year-old actor, perhaps best known for his starring role as Keith Partridge on the 1970s series THE PARTRIDGE FAMILY, tells PEOPLE that he has decided he will no longer tour and instead, concentrate on his well being and happiness. "I want to focus on what I am, who I am and how I've been without any distractions," he says. "I want to love. I want to enjoy life."

In addition, Cassidy reveals that his grandfather and mother also suffered from the debilitating disease, sharing "I was in denial, but a part of me always knew this was coming." He says of his mother's battle, "In the end, the only way I knew she recognized me is with one single tear that would drop from her eye every time I walked into the room. ... I feared I would end up that way."

In a show of support, actor and radio personality Danny Bonaduce, who portrayed younger brother Danny Partridge on the '70's sitcom, took to Twitter yesterday to send his former co-star his good wishes:

In addition to his TV and music career, Cassidy has appeared on Broadway in 1993's BLOOD BROTHERS, 1982's JOSEPH AND THE AMAZING TECHNICOLOR DREAMCOAT and 1969's THE FIG LEAVES ARE FALLING. He is the son of Jack Cassidy and step-son of theater actress Shirley Jones.

Photo Credit: Linda Lenzi