Women with severe mental illness are up to five times more likely to be victims of sexual assault, a new study suggests.

The study, conducted by researchers at the University College London and King's College London, also found that women with mental problems are two to three times at a greater risk of suffering from domestic abuse.

The study was based on data from 303 psychiatric outpatients. Around 60 percent of the patients had schizophrenia. The study also included 22,606 respondents from general population. Women in the test group were in contact with community services for a year.

The researchers found that 40 percent of the women with mental illness were victims of rape or attempted rape in adulthood. Around 53 percent of this group had attempted suicide due to sexual assault. This compared to seven percent of women in the general population who were victims of rape.

The study also shows that 12 percent of men with severe mental illness were sexually assaulted compared to 0.5 percent of the general population.

"The number of rape victims among women with severe mental illness is staggering," said lead author Dr Hind Khalifeh of UCL's Division of Psychiatry.

 "At the time of the survey, 10% had experienced sexual assault in the past year, showing that the problems continue throughout adulthood. Considering the high rate of suicide attempts among rape victims in this group, clinicians assessing people after a suicide attempt should consider asking them if they have been sexually assaulted. Currently this is not done and so patients may miss opportunities to receive specialist support," said Khalifeh in a news release.

Domestic violence was also high among people with severe mental illness. Around 69 percent of women and 49 percent of men in this group reported domestic violence.

The researchers said that there is a strong link between psychiatric issues, sexual assault and domestic violence. However, they haven't established a cause and effect relationship. According to the study authors, violence might have contributed to the mental illness.

Medical Research Council and the Big Lottery funded the study and it is published in the journal Psychological Medicine.