TURKU, Finland, April 2 (UPI) -- A recent survey, conducted in Finland, found nearly 4 percent of respondents reported having frequent nightmares in the past month. More than 28 percent of those with frequent nightmares admitted to having severe depressive symptoms. Some 17 percent said they had frequent bouts of insomnia.
When researchers at the University of Turku parsed the data, they found the three independent symptoms most predictive of frequent nightmares were insomnia, exhaustion and "negative attitude toward self," a symptom of depression.
"Our study shows a clear connection between well-being and nightmares," lead study author Nils Sandman, a researcher with Turku's Center for Cognitive Neuroscience, said in a press release. "This is most evident in the connection between nightmares and depression, but also apparent in many other analyses involving nightmares and questions measuring life satisfaction and health."
Nightmares are defined as any unpleasant dream that elicits feelings of horror, despair, anxiety or great sadness. Frequent or chronic nightmares is a disorder whereby repeated nightmares have negative psychological effects in daily life.
Previous research at Turku has shown that verbal therapy, whereby participants recount their nightmare and connect it with a happy ending, can help patients alleviate the frequency and associated anxiety of recurring nightmares.
The latest study did not attempt to locate causality, but previous research suggests stress and anxiety can encourage nightmares -- as can living and sleeping in an uncomfortable environment.
But the chicken-and-egg question remains: do nightmares encourage sadness and anxiety, or vice versa? Or do both feed off of each other?
Sandman hopes additional research will illuminate causal pathways.
"It might be possible that nightmares could function as early indicators of onset of depression and therefore have previously untapped diagnostic value," he said. "Also, because nightmares, insomnia and depression often appear together, would it be possible to treat all of these problems with an intervention directed solely toward nightmares?"
The research was published this week in the journal Sleep.