David Cassidy Opens Up About His 'Beautiful' Son — and Why He Doesn't Have a Relationship with His Daughter

After revealing that he has been battling dementia since 2015, David Cassidy is opening up about his complicated relationships with his two children – Beau and Katie.

“I’ve never had a relationship with her,” Cassidy, 66, exclusively tells PEOPLE of his only daughter — who has appeared on Gossip Girl and Arrow.

“I wasn’t her father. I was her biological father but I didn’t raise her,” he says. “She has a completely different life.”

Though Cassidy says he and his daughter, whose mom is former model Sherry Williams, are no longer in contact, he is impressed with the woman she has become.

“I’m proud of her,” adds Cassidy. “She’s very talented. It’s hard for me to even accept how old she is now, like 30.”

While the Partridge Family star has previously admitted that his struggles with alcohol abuse throughout the years have affected his personal relationships, Cassidy says he still “very much” has a relationship with his only son, Beau.

“He’s just one of the best people you’ll ever meet in your life and it’s that that I’m proud of,” says Cassidy.

• For more on how David Cassidy is coping with his dementia diagnosis, pick up this week’s issue of PEOPLE, on newsstands Friday

Though former the teen idol has admitted to having kept his diagnosis a secret, he says Beau, whose mother is Cassidy’s ex-wife Sue Shifrin, has been fully aware.

“He knows that I’m just a little off,” he says. “Sometimes he cocks his head at me a little bit and goes, ‘Dad do you remember?’ and I say, ‘No, I know I do, I remember.’ He’ll give me reminders once in a while.”

“He just turned 26,” he adds. “He’s such a beautiful person.”

Now, as Cassidy — who will also be sitting down with Dr. Phil McGraw on March 1 — comes to terms with his condition, he has made the decision to stop touring as a musician to concentrate on his health 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.”

Cassidy will appear on Dr. Phil to discuss his diagnosis in a special episode airing Wednesday, March 1.