Researches point that women are more prone to addiction than men. But what makes young women vulnerable and increases their chances to experience rape or serious sexual assault? A new study made by the Forensic and Legal Medicine team at the University of Ulster, Northern Ireland, has discovered that the answer can be women's binge drinking.

They team checked toxicology results coming from victims of alleged sexual assaults during 1999-2005. The average alcohol amounts at the time of the alleged assaults were about three times higher than the drink/driving threshold.

This challenges the opinion that the consumption of 'date-rape' drugs or 'spiking' of drinks would be the main factor involved in such events. The researchers did not find any record of date rape drugs like GHB, Rohypnol or ketamine, but they warned that delays in reporting the assaults or sample taking could have provided enough time for the drugs to be expelled from the organism.

The samples revealing alcohol, drugs or the presence of both rose from 66% in 1999 to 78% in 2005; also the cases of high or very high alcohol amounts consumption increased significantly in the same time interval.

The presence of drugs, other than alcohol, doubled in the same time interval, but how they were connected to the events was unclear. Many of these drugs were both prescription or recreational drugs. Drugs employed for spiking drinks were also detected, but they were willingly consumed by the victim.

"This research confirms the findings of other studies in the UK, US and Australia - that alcohol is a major contributor to vulnerability to sexual assault in social situations and acquaintance rape." said co-author Dr Janet Hall.

"Given the very high levels of alcohol consumption by some alleged victims, the findings also raise the question of what constitutes valid consent to sexual activity. The capacity to give informed consent at these levels of alcohol consumption is very questionable." she said.

"Further study is now required to give a more accurate picture of the involvement of alcohol and drugs in cases of alleged sexual assault." said lead researcher Dr. Tara Moore.

"Avoidance of mixing different alcoholic drinks in one sitting and avoidance of mixing alcohol with other substances such as prescription medications or recreational drugs, will help reduce the vulnerability, in social settings, to sexual assault or even rape," wrote the authors.