When seniors are admitted to hospital, there's a strong likelihood they will develop a condition known as delirium. They become confused, may not be able to recognize family or friends, develop delusional thoughts and may think people are trying to cause them harm.
There's been little research into the underlying causes of delirium, which affects at least one in five hospital patients over the age of 65. But experts believe it probably results from a combination of factors, including being in an unfamiliar environment, the inability to get a proper night's sleep, the added stress of being seriously ill and, in some cases, early indications of dementia.
The elderly may also be at elevated risk of delirium because of hormonal changes that accompany the aging process. In particular, they tend to produce lower levels of melatonin - the hormone that helps to regulate the body's sleep-wake cycle.
As well, a few studies have indicated that patients suffering from delirium have especially abnormal levels of the hormone.
Researchers at Lawson Health Research Institute in London, Ont., decided to see what would happen if they gave older patients melatonin supplements soon after being admitted to hospital.
For the study, the researchers recruited 145 patients, half of whom were given melatonin nightly while the other half received a placebo.
The results, published in the International Journal of Geriatric Psychiatry, were dramatic: Only 12 per cent of patients in the melatonin group developed delirium, compared with 31 per cent of those who received the placebo.
"We really think we are on to something very exciting," said the lead researcher, Tareef al-Aama.
He hopes to do a follow-up study involving more patients. "If we can replicate the results in a larger trial then this should really be a breakthrough," he said.
There is good reason to prevent delirium. Patients with the condition are at an elevated risk of medical complications, rehospitalization and death.