London, April 3 (IANS): Showing a clear connection between overall well being and nightmares, Finnish researchers have found that symptoms of depression and insomnia are the strongest predictors of having frequent nightmares.

"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," said lead study author Nils Sandman, researcher in the centre for cognitive neuroscience at the University of Turku in Finland.

Results show that 3.9 percent of participants reported having frequent nightmares during the previous 30 days, including 4.8 percent of women and 2.9 percent of men.

Frequent nightmares were reported by 28.4 percent of participants with severe depressive symptoms and 17.1 percent of those with frequent insomnia.

Further analysis found that the strongest independent risk factors for nightmares were insomnia, exhaustion and the depressive symptom of "negative attitude towards self".

A nightmare disorder may occur when repeated nightmares cause distress or impairment in social or occupational functioning.

For the study, the team analysed data from two independent cross-sectional surveys of the Finnish general adult population conducted in 2007 and 2012.

Participants were 13,922 adults between 25 and 74 years of age. Fifty-three percent were women.

It might be possible that nightmares could function as early indicators of onset of depression and therefore have previously untapped diagnostic value.

"Because nightmares, insomnia and depression often appear together, it may be possible to treat all of these problems with an intervention directed solely toward nightmares," the authors concluded in a paper which appeared in the journal Sleep.