Campaigners have called for types of psychological abuse to be made a crime in a bid to save more victims of domestic violence.
Three groups have urged the Government to criminalise "coercive control", patterns of abusive behaviour and causing psychological harm to make it easier to prove long-running abuse.
Coercive control was included in the Home Office definition of domestic violence last year, but it is not an arrestable offence.
It can include being excessively jealous, isolating your partner from family and friends, controlling what they wear or deliberate sleep deprivation and threats.
Two women in the UK each week are killed by their partners and campaigners from Women's Aid, the Sara Charlton Charitable Foundation and stalking advice service Paladin said the most dangerous cases involve domestic violence, stalking and this type of control.
Antonia Packard, from the foundation, said: "The Home Office domestic violence definition was amended in March 2013 to include coercive control.
"Without a legal framework to support it, this definition is largely ineffective and isn't yet meaningfully impacting victims' lives.
"In the absence of an effective statutory framework, domestic violence is not seen as a pattern of abuse that leads to two homicides every week."
The campaign groups carried out an online survey of 258 abuse victims between December 2013 and February this year and 88% said the criminal justice system did not take psychological harm into account. A total of 94% (243) felt that mental cruelty could be worse than physical violence.
Of those questioned, 88% (228) had experienced domestic violence for more than a year.
Paladin director Laura Richards said: "It is possible for the law to criminalise a course of conduct and move beyond physical injury; stalking laws now allow the criminal justice system to take account of patterns of controlling behaviour after a relationship has ended, but often this is far too late for victims as the behaviour has been allowed to escalate.
"We now need to apply the same standard to domestic violence.
"The legislative framework must change to take account of a course of conduct, target patterns and address a broad range of harm and focus more on early intervention and prevention and to better protect victims."
The groups said that current laws focus too much on individual criminal acts rather than a long-running pattern of behaviour.
Polly Neate, chief executive of Women's Aid, said: "These survey results clearly reflect what our member services have been telling us for a long time: that the criminal justice focus on individual incidents of physical violence cannot reflect the ongoing psychological harm caused by coercive control in intimate relationships.
"We welcome the Government's recognition of coercive control in the Home Office definition of domestic violence and the renewed focus Parliament is giving to this issue.
"Currently two women a week die at the hands of a partner or ex-partner; the next step to preventing these deaths is reform to allow the criminal justice system to take account of patterns of controlling and violent behaviour."