Robin Williams' son Zak has paid tribute to his late father on what would have been his 70th birthday.
Taking to Instagram, Zak, 38, shared a sweet black and white photo of his dad to mark the milestone.
He captioned the snap: "Dad, on what would be your 70th birthday, I would want you to know that your incredible spirit lives within us. Our family will be celebrating you and your memory today. We miss you and love you always!"
Zak also spoke about how being misdiagnosed with Parkinson's disease affected his father's mental health shortly before he took his own life in 2014.
As opposed to Parkinson's disease, the beloved comedian had actually had been contending with Lewy body dementia - unbeknownst to him. The correct diagnosis was made posthumously.
Lewy body dementia is a disease that can affect an individual's thinking, movement, behavior, and mood. It's the second most common type of dementia after Alzheimer's.
Speaking to Max Lugavere on an episode of his podcast The Genius Life released on Wednesday, July 21 - Robin's birthday - mental health advocate Zak recalled, per the Daily Mail: "What I saw was frustration."
He added: "What he was going through didn't match one to one [with what] many Parkinson's patients experience. So, I think that was hard for him."
Father-of-two Zak continued: "There was a focus issue that frustrated him, there were issues associated with how he felt, and also from a neurological perspective he didn't feel great... He was very uncomfortable."
The doting son also called into question the medication that his father had been prescribed as it appeared to have an adverse effect on his health. "Those drugs are no joke," he explained. "They're also really hard on the mind and the body."
"I couldn't help but feel beyond empathy. I couldn't help but feel frustrated for him," Zak added. "It can be really isolating even when you're with family and loved ones."
Robin's son also opened up about how he initially dealt with the loss of his famously kind-hearted father.
He shared: "I was heavily drinking to manage my mental health where it created very harmful issues. For me personally, I was having health issues.
"I was experiencing some psychosis and when I spoke with a psychiatrist I was diagnosed with Post Traumatic Stress Disorder. I was self-medicating through the trauma using alcohol."
Zak received treatment in a 12-step program in addition to group therapy, which he says was helpful in allowing him to come to terms with the passing of the widely-adored Mrs. Doubtfire star.
