During a chat yesterday with Stanford psychiatrist Laura Roberts, MD, I learned that depression is one of the leading causes of missed work among U.S. adults. I had no idea, but the numbers are staggering: As the Centers for Disease Control and Prevention reports, depression leads to 200 million lost workdays in the U.S. annually - costing employers $17-44 billion.
As it turns out, though, depression isn't the only common mental disorder that can lead to workplace disruptions. In a recent study (subscription required) appearing in the journal Acta Psychiatrica Scandinavica, Norwegian researchers followed 13,436 participants for up to six years and showed that depression and anxiety were predictors of the onset, duration and recurrence of sick leave. They also found that the risk of prolonged absence and repeated sick leave was highest among people with both illnesses, and that anxiety may actually be more problematic, from an employment perspective, than depression.
Anxiety alone is a stronger risk factor for prolonged and frequent sick leave than depression alone
"Surprisingly, we found that anxiety alone is a stronger risk factor for prolonged and frequent sick leave than depression alone. Further, anxiety seems to be a relatively stable risk factor for sick leave, as we found an increased risk of sickness absence up to six years after the anxiety level was assessed," says Ann Kristin Knudsen... lead author of the study and a PhD student at the University of Bergen and the Division of Mental Health at the Norwegian Institute of Public Health.
Knudsen and her colleagues note that their study is the first to show the effect of mental disorders on sick leave over a long period of time, and they discuss the implications of their anxiety findings in the paper:
Most clinicians are aware of the role depression can play in precipitating and perpetuating sickness absence. However, the results presented in this study suggest anxiety may be even more important... Further work is needed in understanding how health professionals dealing with sickness absence can best identify anxiety and other [depression] symptoms and prevent further prolongations or recurrence of any sickness absence episode.