Many of Jimmy Savile's victims were ignored or laughed at when they revealed at the time that he had sexually abused them.
Others stayed silent because they were convinced they would not be believed as the British radio and TV presenter was such a powerful and influential character.
Some victims were even told they were "lucky someone like Savile had paid them attention", according to the report by UK children's charity NSPCC.
A significant number of the men and women interviewed have still not confided in friends and family about the abuse, it said.
Savile died aged 84 in October 2011 - a year before allegations that he had sexually abused children were broadcast in an ITV documentary.
The revelations about the former BBC presenter of Top Of The Pops and Jim'll Fix It prompted hundreds of victims to come forward with claims that they were attacked at BBC premises or in other institutions, including hospitals.
According to the report, Would They Actually Have Believed Me?, some of the victims, who were aged between eight and 26 when Savile assaulted them, told hospital staff, who dismissed their claims.
One of the 26 victims interviewed by NSPCC counsellors went to the police but no action was taken. The vast majority were children when they were abused but four were adults.
The NSPCC said the research, which was commissioned by Her Majesty's Inspectorate of Constabulary, highlighted the "devastating scars" that victims had suffered from the abuse, with some turning to drink and drugs to cope.
Others have suffered mental illness, had poor relationships or contemplated suicide, it said.
"The responses these victims received when they first revealed Savile's sickening crimes makes heart-rending reading," said Peter Watt, the NSPCC's director of national services.
"They were ignored, dismissed, not believed, laughed at and, astonishingly, told in some cases they should feel lucky he had paid them attention.
"Half a century on, the world finally discovered just how dreadful his crimes were - something these men and women had known all that time but felt powerless to do anything about.
"The anger, frustration and sheer helplessness of the situation obviously damaged their lives in various ways. But they showed true courage in coming forward once more to talk about their experiences and hopefully they can now start to put the terrible trauma behind them."
