A recent study found that those with both mood and anxiety disorders experienced more insomnia than those with one or neither disorder.
The study also found insomnia was linked to poor functioning during the day.
"Tell your doctor if you experience insomnia."
The study, led by Adriane M. Soehner, MA, from the Department of Psychology at the University of California at Berkeley, and her colleague, Allison G. Harvey, PhD, analyzed the data from the National Comorbidity Survey-Replication, which included 5,692 respondents.
Most of these respondents, 3,711, did not have a mood or anxiety disorder. There were 327 who had only a mood disorder, 1,137 who had only an anxiety disorder and 517 who had both a mood disorder and an anxiety disorder.
The respondents were assessed using a World Health Organization interview to determine their sleep quality and quantity and how well they functioned during the day in eight areas over the past 30 days.
These areas included self-care, such as dressing or bathing, and mobility, such as how well the participants moved, stood or walked. Their cognition (concentration and memory), and their social functioning were also assessed.
The other four areas included how much time they spent unable to do normal daily activities or work, how much reduced amount of work they got done, the reduced quality of their work and the effort needed to carry out daily activities.
They found that the respondents who had both mood and anxiety disorders reported much more difficulty with insomnia compared to those with just one of these disorders or no disorder.
Those with mood and anxiety disorders were 42 to 63 percent more likely to complain of severe insomnia.
Those who had only a mood disorder or an anxiety disorder were about 25 to 46 percent more likely to have severe insomnia compared to those with neither mood nor anxiety disorders.
The researchers also found that those with both a mood and anxiety disorder who complained of severe insomnia within the past year had more days when they were unable to do their daily activities or work as effectively as normal in all eight categories.
The other three groups also had more days of poor work in all areas except self-care (and in mobility if they had a mood disorder) if they had had severe insomnia.
The authors concluded that having a mood disorder and an anxiety disorder at the same time increased the likelihood that a person would experience severe insomnia.
They also determined that severe insomnia was linked to substantial difficulty in doing day-to-day activities or work.
These findings match up with past research, according to William Kohler, MD, the director of the Florida Sleep Institute in Spring Hill, Florida.
"Previous studies have shown that the development of insomnia may be a harbinger for a return to depression in people that have depression so there are definitely correlations that have been shown previously between mood disorders and insomnia," Dr. Kohler said.
"This is an interesting study, but it's kind of difficult to tell what's the cart and what's the horse when you're talking about insomnia and mood disorders," he added. "We also have known that insomnia increases with stress, which obviously is related with anxiety."
The study was published in the October issue of the journal Sleep. The research was funded by the National Institute of Mental Health. The authors declared no conflicts of interest.