Mental health services across Norfolk and parts of Suffolk are to be provided by one organisation.
The change will affect the mentally ill and their families and carers.
Council social services and the NHS had each been providing separate programmes to patients in the past.
The Norfolk Mental Health Care NHS Trust will be in charge of the new integrated service, with Norfolk and Suffolk county councils offering assistance.
The service, aimed at people with mental health problems, their families and other carers, is to be launched on 1 April following a consultation period.
Amanda Hedley, the trust's director of service, said: "Staff across health and social care already work together in many areas so this is the next logical step."
Staff and people who use the services in Norfolk and Waveney in Suffolk will be asked for their input on the decision during a consultation process, which will be held over the next few months.
When the merger takes place, about 130 Norfolk social services staff will be moved to the new organisation. No jobs will be lost.
Chris Mowle, the cabinet member responsible for social services in Norfolk, said eventually budgets from both areas will be merged.
Services have already been integrated in West Norfolk, where social services joined up with West Norfolk Primary Care Trust earlier this year.