Using Big Data, the researchers found that people with restless legs syndrome had a 2.7- fold higher risk of suicide or self-harm, even if they didn't suffer from conditions such as depression, insomnia, diabetes and so on.
Restless legs syndrome causes an uncomfortable feeling in a person's legs resulting in the urge to move them, often during the night.
"Our study suggests that restless legs syndrome isn't just connected to physical conditions, but to mental health, as well," said Xiang Gao, Associate Professor at Penn State University in the US.
The study looked at health records of 24,179 people who had been diagnosed with RLS and 145,194 people who did not have RLS.
All participants were free of suicide and self-harm at the baseline of the study.
After analysing the data, the researchers found that people, who had restless leg syndrome, had a 270 per cent higher chance of suicide or self-harm than people who did not.
The risk did not decrease even when the researchers controlled for such factors as depression, sleep disorders and common chronic diseases.
"After controlling for these factors, we still didn't see the association decrease, meaning RLS could still be an independent variable contributing to suicide and self-harm," said Muzi Na from Penn State.
"We still don't know the exact reason, but our results can help shape future research to learn more about the mechanism."
The study was published in the Journal of the American Medical Association (JAMA) Network Open.
( With inputs from IANS )