Robin Williams’ son wished his dad a happy 70th birthday on Instagram Wednesday July 21st). 

Zak Williams wrote in a caption, "Dad, on what would be your 70th birthday, I would want you to know that your incredible spirit lives within us.”  

The 38-year-old discussed his father’s death in more detail on an episode of The Genius Life podcast, released the same day.  According to People, he told the outlet that his father not only struggled with focus and other neurological symptoms, but that his medications were “really hard on the mind and body. 

After Robin's suicide, Zak says he was diagnosed with post-traumatic stress disorder and turned to alcohol to cope.  However, he has gone through a 12-step program for addiction recovery and is now working as a mental health advocate. 

Robin committed suicide in 2014, two years after being misdiagnosed with Parkinson’s disease. It was discovered during his autopsy that he was suffering from Lewy body disease.