Hilary Duff mourns Robert Carradine, her ‘Lizzie McGuire’ on-screen dad

Hilary Duff has expressed her heartbreak following the death of her former Lizzie McGuire co-star Robert Carradine, who passed away at the age of 71.

Carradine, best known for playing Sam McGuire, Hilary’s on-screen father in the Disney teen hit, took his own life after a nearly two-decade battle with bipolar disorder, his brother Keith Carradine confirmed. Bipolar disorder is a mental health condition characterized by extreme mood swings.

"This one hurts. It’s really hard to face this reality about an old friend. There was so much warmth in the McGuire family and I always felt so cared for by my on-screen parents. I’ll be forever grateful for that. I’m deeply sad to learn Bobby was suffering. My heart aches for him, his family, and everyone who loved him," she captioned the post.

"It is with profound sadness that we must share that our beloved father, grandfather, uncle, and brother Robert Carradine has passed away. 

In a world that can feel so dark, Bobby was always a beacon of light to everyone around him. We are bereft at the loss of this beautiful soul and want to acknowledge Bobby’s valiant struggle against his nearly two-decade battle with bipolar disorder. We hope his journey can shine a light and encourage addressing the stigma that attaches to mental illness."