Southwark Coroner's Court was told that Mr Edwards - whose colourful life and role in the robbery was made into the 1988 film Buster - suffered from acute depression and had a serious drink problem. He had made two previous suicide attempts.
Sir Montague Levine, the coroner, said that Mr Edwards, 62, who spent three years on the run in Europe and Mexico before serving nine years for his part in the £2m raid on the Euston-to-Glasgow train in 1963, drank a bottle of vodka a day.
Medical reports showed his family had "been at the end of their tether" trying to stop him drinking. But a report from one specialist noted he doubted that Mr Edwards really wanted to stop.
When Mr Edwards's brother, Terence, discovered him hanging from a metal girder in the garage near his flower stall at Waterloo station, he had enough alcohol in his body to kill someone unused to drink, the court was told. A small bottle of vodka - one-third full - was found discarded by his body. The pathologist, Dr Vesna Djurovic, said he had died just before he was discovered.
Sir Montague said the "enormous quantity of alcohol" in his blood - more than four times the drink-drive limit - cast doubt on his ability to form the intent to take his own life. But he added he was certain no other person was involved.
Mr Edwards's wife, June, was too distressed to attend the hearing but his daughter, Nicola, was present. She left the room during the pathologist's evidence. Sir Montague said the family could take comfort from the knowledge that Mr Edwards must have lost consciousness quickly and suffered no pain.
The hearing was a quieter affair than the elaborate send-off for Mr Edwards in December which was attended by a number of superannuated career criminals, including two of the nine surviving train robbers and Charlie Kray, elder brother of the Kray twins.
But there was still a touch of style. The family was collected from court by a chauffeur-driven Rolls-Royce with heavily tinted windows.
A family friend, who was allowed to ask questions of witnesses, provided the only excitement when he was chased by photographers after becoming rather camera shy outside the court.
In court, Terence said his brother had been depressed that his business was losing trade because of the extension to the London Underground Jubilee Line. But he added he was sure the depression and drinking stemmed from his nine years in prison.
Mr Edwards opened the stall after being released from prison in 1975. In a magazine interview the man who was played on screen by Phil Collins gave an insight into the predicament of going straight.
"I know I'm lucky to have got a chance to have this stall and be my own boss but it's so dreary compared with the life I used to lead," he said.
"It wasn't even the money. I've been on jobs that haven't netted me a penny but, oh, does the adrenaline flow."