Nightmares may increase suicide risk: Study

London: Do you frequently have nightmares? You might be at an increased risk for suicide, according to a new study which has found a relationship between sleep problems and suicidal thoughts, plans and attempts.

Researchers found that the relationship between nightmares and suicidal behaviours is partially mediated by a multi-step pathway via defeat, entrapment and hopelessness.

Results show that suicidal thoughts, plans or attempts were present in 62 per cent of participants who experienced nightmares and only 20 per cent of those without nightmares.

Multiple analysis suggest that nightmares may act as a stressor in people with post-traumatic stress disorder (PTSD).

The nightmares may trigger specific types of negative cognitive thoughts - such as defeat, entrapment and hopelessness - which reinforce suicidal thoughts and behaviours, researchers said.

The pathways between nightmares and suicidal behaviours appear to operate independent of comorbid insomnia and depression, they said.

"PTSD increases the risk of suicidal thoughts and behaviour, and our study shows that nightmares, a hallmark symptom of PTSD, may be an important treatment target to reduce suicide risk," said Donna L Littlewood from University of Manchester in the UK.

"This study emphasises the importance of specifically assessing and targeting nightmares within those individuals experiencing PTSD. In addition, monitoring and targeting levels of negative cognitive appraisals such as defeat, entrapment, and hopelessness, may reduce suicidal thoughts and behaviours," said Littlewood.

According to the American Academy of Sleep Medicine, nightmares are vivid, realistic and disturbing dreams typically involving threats to survival or security, which often evoke emotions of anxiety, fear or terror.

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

Nightmares beginning within three months of a trauma are present in up to 80 per cent of patients with PTSD, and these post-traumatic nightmares may persist throughout life.

Data for the study was collected from 91 participants who had experienced traumatic events, 51 of whom met criteria for PTSD currently, and an additional 24 of whom reported a prior diagnosis of PTSD, researchers said.

Nightmares were measured by summing the frequency and intensity ratings of relevant items on the clinician-administered PTSD scale. Participants also completed questionnaire measures of suicidal behaviour, hopelessness, defeat, and entrapment, they said.

Given the interactions between insomnia, PTSD, and suicide, a measure of insomnia was included as a covariate. Analysis was also conducted with and without those participants who had comorbid depression.

The findings were published in the Journal of Clinical Sleep Medicine.