Dr. Oz urges patients and doctors alike not to ignore insomnia as a link to other potentially more serious disorders, Examiner.com reports.

Dr. Oz said chronic insomnia could also be a warning sign of depression and anxiety. This is also something you should never ignore, as depression is a serious health condition that could have devastating consequences.

The world is reeling from the tragic suicide of actor Robin Williams, who hanged himself Aug. 11 at his California home, USA Today reported. In a statement, Williams’ rep revealed Robin had suffered from severe depression, both recently and throughout his adult life.

Dr. Ash said symptoms of depression-induced insomnia include recurring bad dreams, extreme sensitivity to noise such as a ticking clock, and racing thoughts that keep you up at night.