I've also been treated for depression in the past though feel I'm winning these days. You would think someone like Robin Williams had it all in terms of lifestyle, money, a career he can be immensely proud of, but it's just not that simple.
The genie in Aladdin, Mrs Doubtfire, Mork... all great childhood memories.
I don't remember him much from his acting career in Mork & Mindy because I have never even seen the show. However he was a great acting talent that is truly irreplaceable because of the acting he portrayed in many of the movies that I have enjoyed over my childhood.
All I can say is Rest in Peace Robin. We will miss you big man.