Researchers have reported benefits from interacting with PARO, although the studies were often small, short term or lacked control groups. At facilities in Texas and Kansas, for instance, investigators followed 61 residents with dementia who had 20-minute group sessions with a PARO three days a week for three months. Their stress and anxiety decreased, the researchers found, and they needed less medication for pain and problem behaviors.

Front Porch, a nonprofit senior living provider, acquired several PAROs in 2015 and tracked their effects through about 900 surveys reporting residents’ interactions. Over six months, the staff reported that the robots — which acquired names and, at holidays, festive outfits — helped calm residents, increased their social behavior and improved mood and appetite…

One of the largest studies, underwritten by United HealthCare and AARP, distributed free Joy for All robots to 271 seniors living independently.

All the seniors suffered from loneliness, according to a screening questionnaire. At 30 and 60 days, “there was improvement in their mental well-being, in sense of purpose and optimism,” said Dr. Charlotte Yeh, chief medical officer of AARP’s business subsidiary and a study co-author. The study also found “a reduction in loneliness,” Dr. Yeh said, although the questionnaires showed that participants remained lonely.