Sleep aids including Restoril and Ambien in the elderly improve sleep patterns but also represent significant risks, a new study says.

Researchers at the Centre for Addiction and Mental Health in Toronto reviewed 24 trials that included 2,417 participants aged 60 or older who were treated for insomnia with so-called sedative hypnotic pills or inactive placebo pills.

Compared to the placebo, sedative use was associated with statistically significant improvements in sleep quality, total sleep time and the number of nighttime awakenings, according to researchers.

But adverse effects, such as thinking difficulties and daytime fatigue, were found to be more common with the participants taking the sleep aids than those in the placebo group, the report said. Also, risks were greater in elderly who were at high risk for falls or mental impairments, the report noted.