In many cases severe depression is linked to the mis-use of drugs. Robin Williams, as brilliant as he was, was a cocaine user. The drug use sometimes precedes the depression, and contributes to it's onset, but often, the depression comes first and then the person turns to drug use to self medicate to try and shake off the depression. Drugs are a scourge. I know someone who is taking drugs and drinking and suffering from severe depression. He has attempted suicide on more than one occasion....and he will succeed one day, because no-one can help a person on this road. They have to want to help themselves. Poor Robin.....such a sad end to a brilliant life..........well, we thought it was brilliant, but it probably wasn't so brilliant for him.