Insomnia Hits 'Night Owls' Harder

They have more symptoms and more anxiety about their sleeplessness, study finds.

By Alan Mozes
HealthDay Reporter
Monday, April 16, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

MONDAY, April 16 (HealthDay News) -- Insomnia's effects may depend on just when a person prefers to hit the sack.

According to new research, "night owls" suffer more from insomnia than those who try and get their z's earlier on.

Night owls also tended to be more concerned about their insomnia than the early-to-bed folks, despite the fact that they actually spent relatively more time in bed and got more sleep overall, the researchers found.

"We suspected that there may be more severe symptoms among night owl insomniacs," said the lead author, Jason C. Ong, an instructor of psychiatry in the Sleep Disorders Clinic at Stanford University in Palo Alto, Calif. "But we also found they exhibited much more distress about their sleep, in terms of attitude. They felt they needed eight hours of sleep, and they're not getting it, and that was associated with feelings of depression and irritability and that kind of thing."

Ong and his colleagues published their findings in the April 15 issue of the Journal of Clinical Sleep Medicine.

According to the researchers, physiological "insomnia" -- which affects 30 percent of American adults -- refers to disorders defined by poor sleep quality and difficulties falling and staying asleep.

By contrast, another type of sleep disturbance, known as a "circadian rhythm sleep disorder" (CRSD), can arise when the hours of your natural internal clock do not line up well with your social or professional schedule. The resulting "mismatch" can undermine your ability to fall asleep or wake up.

Traditionally, CRSD has been viewed as distinct from insomnia. Experts have theorized that when circadian rhythms match your daily schedule, you should theoretically experience problem-free sleep.

The new study focused on 312 outpatients (60 percent women) who had already started to undergo group behavior therapy for insomnia at the Stanford sleep clinic between 1999 and 2004.

Ong and his team asked all the men and women to indicate their usual (pre-insomnia) preference for sleep scheduling -- when they liked going to bed and waking up.