Debby Hannigan tried for years to obtain the medical records of her great-grandaunt, Breta Meria Conole, who spent more than two decades in a New York state psychiatric hospital during the 20th century. Hannigan thought the records might hold clues to mental health issues in her family, including her oldest daughter’s depression. She wrote to the state of New York twice. The second time she included a note from her daughter’s therapist, who said the details would help the family understand their medical history. Both times, the state turned her away.

Hannigan’s experience is not unique. Descendants of the hundreds of thousands of people once held in state psychiatric institutions are increasingly seeking access to records that could illuminate patterns of depression, suicide, and other conditions across generations, but a tangle of state laws and federal privacy rules keeps many of those records sealed.

The federal Health Insurance Portability and Accountability Act, enacted in 1996, protects each patient’s identifiable health information for 50 years after death. Some states offer easily accessible routes to older material. Ohio law allows the closest living relative to request records, and anyone can request them after 50 years. Maine has similarly broad access rules.

But many other states are far more restrictive. New York permits mental health records to remain sealed “in perpetuity,” according to the state’s Office of Mental Health. Records can be released to a patient and immediate family members, but generally not to more distant descendants. They have also been released to medical professionals “with a justification” and to historians who agree not to name individual patients. “It really does piss me off that we couldn’t just say, ‘Hey, we’re the descendants, here’s the proof, now tell us what you know!’” said Doug Clarke of Alfred, N.Y., who tried without success to access records of his great-grandfather, hoping to understand depression and bipolar disorder in his generation.

Massachusetts was similarly restrictive until a reform push culminated last year in a new law that made public state hospital records that are at least 75 years old, plus records for anyone dead at least 50 years. The change followed a commission report that detailed the state institutions’ history of abuse and neglect, including patient sterilizations at a state hospital in Monson. Alex Green, a commission member, suggested the state’s refusal to release the records amounted to a “cover-up” of the decades of abuse disabled people endured.

Now some lawmakers and families are pressing New York to follow suit. State Sen. Pat Fahy, a Democrat from the Albany area, introduced a bill this year that would designate records and information relating to a patient who has been deceased for 50 years or longer as historic records, no longer subject to privacy protections. Fahy pointed to New York’s own troubled institutional history, including the Willowbrook State School on Staten Island, where developmentally disabled children once lived in deplorable conditions. “If the person is deceased, there should be an availability of these records to help give the family closure,” Fahy said. “Learning from our history is one of the best ways to give us insight into how we do better in the future.”

The records that exist can be remarkably detailed. Staff at the hospitals often took extensive notes, describing patients and their symptoms, and in some cases took photographs, said Dr. Laurence Guttmacher, a former clinical director of the Rochester Psychiatric Center. “We had this incredibly rich trove of records” at the Rochester hospital, he said, and he received about two requests a month from families. State officials told him he could not release the information. Some records were damaged or lost over the years, and surviving documents may be poorly organized, but a substantial amount of information still exists, Guttmacher said.

For families coping with mental illness, the stakes are medical, not merely historical. “Would you want to know if your grandfather died of a heart attack?” said Dr. Christine Moutier, chief medical officer for the American Foundation for Suicide Prevention. “It’s information that you can use to understand how vigilant to be.”

Historians and genealogists note that families have some alternative routes to information. Online services such as Ancestry.com offer old census records that can reveal whether an ancestor was in a state institution at the time a census was taken. Veterans’ military pension files sometimes contain mental health details. Old newspapers routinely reported when residents were sent to state institutions.

At the peak of institutionalization in the 1950s, more than 500,000 people lived in state psychiatric hospitals, according to Ryan Thibodeau, a St. John Fisher University researcher involved in the push to change New York’s law. “Their descendants are everywhere,” he said.