New research reveals that a high percentage of military personnel with sleep disturbances met the criteria for nightmare disorder, reports Psych Central.

However, few of them reported nightmares as a reason for sleep evaluation. The presence of a nightmare disorder increases the risk of other sleep and mental health disorders. Investigators found that 31 percent of military participants with reported sleep issues had clinically significant nightmares, and trauma-related nightmares occurred in 60 percent of them.

Participants who met criteria for nightmare disorder were five times more likely to have post-traumatic stress disorder (PTSD), four times more likely to have depression, three times more likely to have anxiety, and two times more likely to have insomnia.