Tony Calder has it wrong about Nico. She didn't "top herself". She suffered a brain hemorrhage while riding a bicycle in Ibiza, and several factors led her to die from this. First, it was some time before she was found, by the side of the road. Second, after being taken to hospital she was not given priority treatment, as she should have been given in that situation, largely because she was not recognized and it was assumed that she was just some old bag lady, so she was sidelined for a long and crucial interval.
Had there not been this neglect and had she been discovered sooner, she might still be alive today. She had stopped using heroin by this time, and had been off drugs for about a year.