Elderly who have persistent trouble sleeping may be at an increased risk for suicide, even when symptoms of depression are not evident, a new study suggests.

The study included a review of health data for nearly 14,500 elderly people aged 67 to 90 years old over a 10-year period. Of the small number of individuals who committed suicide during the study period (21), researchers found that sleep disturbances, independent of depression, predicted an increased risk for eventual death by suicide, according to researchers at Florida State University.

People reporting non-restorative sleep issues were almost twice as likely to die by suicide compared to those without this particular sleep complaint, according to the study, which was presented during the annual meeting of the Associated Professional Sleep Societies in Minneapolis.