A new law making coercive control a criminal offence here has been hailed as a life-changer for women in abusive relationships.
Women's Aid said Westminster's extension of the legislation to Northern Ireland was a "very welcome but long overdue move".
Coercive control includes psychological abuse and non-violent intimidation. It has been a crime in England and Wales for four years, and is also outlawed in the Republic.
The chief executive of Belfast and Lisburn Women's Aid, Kelly Andrews, said: "Coercive control is a subtle and insidious form of abuse.
"It may be less visible than a broken nose but it can totally erode the person's core sense of self and identity. They may present to their GP suffering from depression and anxiety, and be prescribed medication while the root cause goes unaddressed."
Ms Andrews said it could be 18 months to two years before the new law comes into force here.
"There will have to be training for PSNI officers and the judiciary, but this law will change lives," she said.
Last year, the PSNI responded to almost 32,000 incidents of domestic abuse, the highest number on record.
Ms Andrews added: "While we are encouraged that more people are coming forward to report to police, we understand that domestic violence still remains massively under-reported.
"It is hoped that this legislation will encourage more victims to come forward to seek the help they need."
Former justice minister Claire Sugden, who campaigned for changes to the law, said: "My heart is bursting."
She said it was to the Government's "hidden shame" that it had done little to address the issue for so long.
"During my time in office, I made tackling domestic abuse my overarching priority. My biggest regret of the Stormont collapse is not fulfilling my promise to get domestic abuse law onto statute while minister," she said.
"Coercive control is constructed through psychological abuse. It's usually the reason why victims don't just leave and also the beginning of physical violence. An accurate description is feeling like always 'walking on eggshells'."
Ms Sudgen said she dedicated the legal change to domestic abuse survivors. "It's their honesty of horrific experiences and their strength telling their stories that will hopefully stop others becoming victims," she said.
"They have started the journey of eradicating domestic abuse in Northern Ireland."
Labour MP Stella Creasy said she was proud of the organisations that had worked for the law change.
"Finally, finally, the voices of women in Northern Ireland are starting to be heard as equals, not afterthoughts," she added.
Ulster Unionist leader Robin Swann welcomed the new law and said it had been "totally unacceptable" that Northern Ireland was the only part of the UK where victims were not protected from coercive control.
"We have led the calls for Westminster to step in, in the absence of a functioning local Assembly and Executive, and I wrote to the Secretary of State in February urging her to act," he said. "People need protecting and the police and courts need powers to take action. Nobody in Northern Ireland should be made to suffer because certain political parties cannot agree to share power and work in the best interest of all our people."
DUP MP Gavin Robinson said it was "clearly in the public interest" for Northern Ireland provisions to be included in the draft legislation, adding: "On this issue, there is a complete political consensus in Northern Ireland."
He urged ministers to go further and include protections against stalking in the new law.
Department of Justice permanent secretary Peter May said: "Any form of domestic violence is completely unacceptable. The new domestic abuse offence will criminalise patterns of coercive and controlling behaviour. This will make it an offence for someone to engage in a course of abusive behaviour (on at least two occasions) against a partner, ex-partner or close family member." He added: "The department has worked closely with the voluntary, community and statutory sectors to prepare an offence that meets the specific needs of people in Northern Ireland."