Mental health service users are still being treated like "second-class citizens" according to the annual report of the Mental Health Commission.
The independent body said the basic human rights of many residents in mental health settings continue to be overlooked.
The 2019 report shows that compliance around the Rules on Seclusion in settings fell by 12%, which was already at a low level of compliance at 33% in 2018.
There was also a decrease in compliance with the Code of Practice on the Admission of Children.
The main reasons reported were adult approved centres not having age-approved facilities or activities for child residents.
The report states that children and young people in crisis are left the unacceptable "choice" between an emergency department, general hospital, children's hospital or an adult inpatient unit.
The commission said they should not be admitted to adult units except in exceptional circumstances.
In 2019, 65% of all child admissions were female. The youngest resident was aged 11. There were 208 instances of overcapacity in 2019.
The majority were due to more emergency admissions. Other reasons included voluntary or involuntary admissions, no available discharges and returns from leave.
There were increases in compliance with the Rules on Mechanical Restraint and the Codes of Practice relating to Physical Restraint and Admission, Transfer and Discharge.
In 2019, the commission took 40 enforcement actions in relation to incidents, events and serious concerns.
The Mental Health Commission said that to make a real and lasting difference in service standards, the mental health system needs to be tackled in a unified way.
It has called on the Government, individual ministers and the Health Service Executive to take up the baton.
MHC Chief Executive John Farrelly called for leadership in the HSE to improve the system.
Speaking on RTÉ's Morning Ireland, he said a culture of seclusion and physical restraint continues to exist in centres and this is not therapeutic, is not a healthcare intervention and is traumatic for patients.
Mr Farrelly said that only 50% of centres are compliant with care plans and there are also problems with physical premises.
These problems are there 'time and time again' and until they are fixed mental health service users will not be treated correctly, he added.
Mr Farrelly said problems in mental health centres are "very solvable", adding that is about proper governance and health care management and about putting the right structures in place.
CEO of the National Coalition for Mental Health Reform, Fiona Coyle, has said the report marks another year of failure to make a meaningful impact on the delivery of fundamental improvements in mental health services in Ireland.
The coalition says it is essential that individuals have a voice and are key decision makers in their own mental health care and treatment.
It described many of the report's findings as 'stark’, and said it is concerned about the significant drop in compliance on rules on seclusion from 2019 to 2018 - which it says is a practice that can have harmful physical and psychological effects.
Mental Health Reform has called for a firm commitment from the new Government to invest in transforming mental health services.
Last month, the Government launched a new mental health policy.
'Sharing the Vision' replaces 'A Vision for Change' - the ten-year mental health policy which expired in 2016.
The Department of Health said the new policy would focus on promotion, prevention and early intervention, service access, coordination and continuity of care, social inclusion, accountability and continuous improvement.
It will be up to the new Minister for Health and the Minister for Mental Health to ensure the new policy - which is not costed - will be implemented.