Mexico’s first report on its progress toward abiding by the agreement is due this year.

Dr. Carlos Campillo Serrano, the director of psychiatric care for Mexico’s Health Ministry, said he hoped that the report would help generate momentum to improve conditions. “We are attentive to its recommendations,” he said.

The budget for mental health has increased to about 2.2 percent of all health spending, from 1.5 percent in 2006, he said, “but the big problem is how we spend the money.”

Among the problems is the lack of trained personnel. Dr. Campillo, who worked with Disability Rights International to give the group access to the hospitals, agreed with the report’s conclusion that there was no community support that would allow many families to care for disabled relatives at home.

As a start, Dr. Campillo said that the government had included mental health coverage in its basic public health care coverage and that the government was studying new legislation to govern treatment. But the problems in Mexico are deep-rooted and difficult to resolve, he said.

Like the earlier report, this one found many of those in the institutions did not need to be there, but as “abandonados” lacked family members or community-based programs to care for them.

The investigators visited 20 psychiatric wards, orphanages, shelters and other public institutions around the country, housing thousands of people, from August 2009 to September 2010, interviewing patients and administrators and reviewing records when possible.

At three psychiatric hospitals, investigators found that staff members relied on extensive use of psychotropic drugs in place of other forms of treatment for aggression and other behavioral problems.