According to The Independent, Robin Williams' Parkinson's medications have played a part in causing the actor to kill himself, as stated by the actor's good friend, Rob Schneider.

The SNL comedian tweeted his insight about the cause of his friend's unexpected death, saying:

Now that we can talk about it, Robin Williams was on a drug treating the symptoms of Parkinson's,"

"One of the side effects is suicide!"

Schneider had maintained a friendship with Williams for 20 years. The Mirror reported that the deceased actor's friends were worried his medications had adversely affected his mental condition.

Parkinson's is developmental disease cause nerve cells damage in the brain, which causes eventual problems in physical mobility or movement.

Experts think that depression become severe as Parkinson's progresses, however, further studies are still underway.

Actor Michael J Fox, was also diagnosed with the same illness since 1991. He was surprised to have heard Williams suffering from the same illness.

The star said he didn't expect the Robin Williams Parkinson's news, as it didn't cross his mind his friend would keep his struggle a secret from friends.

The deceased actor's wife said was quoted as saying Williams was "not yet ready to share publicly" his Parkinson's diagnosis.

Robin Williams Parkinson's revelation should serve as an inspiration to others. It should inspire others to not let the side effects of the medication of the disease overwhelm them.