Inspections by the Mental Health Commission of inpatient centres in three counties have revealed what it calls the "stark contrast" between conditions in a Co Galway unit and other facilities in Kildare and Louth.
Chief Executive Officer John Farrelly said the evidence showed that the mental health service was inconsistent across the country despite being run by the Health Service Executive and that this indicated a deficit in how it was being run.
The reports published today follow annual visits earlier this year by teams led by the Inspector of Mental Health Services, Dr Susan Finnerty.
The largest facility inspected was the Lakeview Unit at Naas General Hospital.
Although it had a capacity to care for 29 patients, it was obliged to send five other patients out of its catchment area to the Department of Psychiatry in the Midland Regional Hospital in Portlaoise, which is 30km away.
The report says the centre "was not suitable for the care and treatment of people with a mental illness" adding that privacy was one of the seven areas in which it had high risk non-compliances.
It states that there were insufficient internal and external spaces for residents to move about and that it had only one sitting room downstairs after 8pm in which there were only 11 chairs for 29 residents.
Overcrowding also resulted in a seclusion room being used as a bedroom on six occasions since the last inspection, the report notes.
At St Ita's Ward in St Brigid's Hospital in Ardee, Co Louth, the report says that while it is registered for 20 beds, just eight were in operation at the time of the inspection and an active process was in place to move residents to community settings.
The centre had three high risk non-compliances in the areas of general health, staffing, and the ordering, prescribing, storing and administration of medicines.
There was no documented evidence that all residents on anti-psychotic medication had received an annual assessment of their glucose regulation, blood lipids, an electrocardiogram, or prolactin levels.
And full records were not available demonstrating residents' completed general health checks.
Menus for residents on special diets were limited and residents were receiving the same meal options for what the report terms as "long periods".
In marked contrast, the 14-bed Creagh Suite at St Brigid's Healthcare Campus in Ballinasloe, Co Galway, which caters for people with dementia, recorded a 97% compliance with regulations.
At the time of the inspection, the nine residents in the long-stay, continuing-care facility were provided with many activities including hand massage, dance and art therapies, life story work; as well as one-to-one social work, psychology, occupational and speech and language therapy, medical, and nursing care.
The report said that residents' bedrooms were personalised, clean and bright and they had access to a secure, dementia friendly garden.
Mr Farrelly said the contrast between a centre with 97% compliance in Galway and less than satisfactory findings in Louth and Kildare was "stark".
In a statement accompanying the reports, he said the commission's evidence was that the mental health service was inconsistent across the country despite being run by same provider.
"This indicates a deficit in the governance and management of our mental health services," he concluded.