Restless nights tied to mental illness, new large-scale study says

Having trouble sleeping? One of the largest studies of its kind says that could be strongly linked to mental illness.

People diagnosed with mental illness in their life were more likely to have poorer sleep quality compared to the general population, the Centre for Addiction and Mental Health (CAMH) said in findings recently published in PLOS Medicine.

“The differences in sleep patterns indicated worse sleep quality for participants with a previous diagnosis of mental illness, including waking up more often and for longer periods of time,” Shreejoy Tripathy, senior author and an independent scientist at CAMH’s Krembil Centre for Neuroinformatics, said in a press release.

“Poor sleep contributes to poor mental health and poor mental health contributes to poor sleep,” explained Michael Wainberg, the study’s lead author and a postdoctoral researcher at centre.

“Sleep pattern differences were a feature of all mental illnesses we studied regardless of diagnosis,” he said, adding that gauging the quality of sleep was just as important as figuring out its effect on people’s mental health.

Previous studies have linked people’s chronic sleep problems to their psychiatric conditions including anxiety, depression, bipolar disorder, and attention deficit hyperactivity disorder.

But Tripathy explained, “until now nobody has looked at objectively measured sleep in the context of mental illness at quite this scale before.”

WRIST DEVICES TRACKED PEOPLE'S BODY MOVEMENTS

To put the study together, data was taken from 89,205 participants in the United Kingdom who agreed to wear an accelerometer on their wrist that tracked their body movement -- 24 hours a day for seven days. The data was then stored in a digital patient data biobank.

Using computational algorithms, researchers broke down the huge amounts of data into metrics, such as people’s bedtime, the time they woke up, naps, and the longest amount of time they had uninterrupted sleep. Then, the team looked at whether people had a diagnosis of mental illness in their life at any point, contrasted to those who hadn’t.

Previous sleep studies have shown the potential benefit of collecting data through these accelerometers and parsing information gathered from people in their natural sleep environments rather than in a laboratory setting.

“Part of why we wanted to do this study is that with the emergence of smartphones and wearables, we have access to data streams that we never had before,” Tripathy said.

Michael Mak, a CAMH psychiatrist and sleep disorder specialist, said that up to 80 per cent of people with mental health disorders can end up spending more time tossing and turning; or have trouble staying asleep or waking up earlier than they’d wanted.

“We know that sleep disturbances cause a great burden to society, including an economic one. And we know that treatments that improve sleep quality, whether it is therapy or some types of medication, can improve mental health outcomes.”

The Krembil Centre for Neuroinformatics is currently in the process of creating a Canadian patient data biobank, similar to the one used in the U.K., to drive future clinical research here and ultimately better personalize patients’ mental health care.