Chronic insomnia may predict the development of anxiety disorders and also indicate current depression.

That’s according to a Norwegian study published in the latest edition of the journal Sleep.

The study defines chronic insomnia as the subjective feeling of having trouble falling or staying asleep most nights for at least a month.

People with chronic insomnia should be screened to see if they have an anxiety disorder or depression, note the researchers. They included Dag Neckelmann, MD, PhD, of the psychiatry department at Haukeland University in Bergen, Norway.

Neckelmann’s team tracked depression, anxiety, and insomnia in more than 25,000 Norwegian adults.

Participants completed a health survey that included questions about chronic insomnia, anxiety disorders, and depression. They took the survey twice — once in the mid-1980s and again 11 years later.

Insomnia, Anxiety Disorders, and Depression

The researchers excluded participants who had anxiety disorders or depression at the time of the first survey.

People who reported chronic insomnia in the first survey were particularly likely to note anxiety disorders in the follow-up survey 11 years later.

Chronic insomnia didn’t predict depression’s development. People with chronic insomnia in the first survey weren’t especially likely to report depression 11 years later in the second survey.

But that doesn’t mean that insomnia and depression weren’t related.

People with chronic insomnia were more likely to have current anxiety or depression than people without insomnia.

The results held when the researchers considered other factors, including participants’ age, sex, and educational level.
Sound Sleep, Less Anxiety?

Easing chronic insomnia might help prevent the development of anxiety disorders, Neckelmann’s team notes.

However, they didn’t test that theory directly. Their study doesn’t prove that insomnia causes anxiety disorders, or that ending insomnia heads off anxiety.

SOURCES: Neckelmann, D. Sleep, July 1, 2007; vol 30: pp 873-880. News release, American Academy of Sleep Medicine.

?© 2007 WebMD Inc. All rights reserved.

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