Insomnia flagged a disputed parasomnia in Ukrainian combatants

Trauma-associated sleep disorder describes nightmares combined with disruptive nocturnal behaviours arising after traumatic experience. It was proposed as a distinct parasomnia in a 2018 theoretical review, on the basis of a limited number of laboratory-documented cases, and it overlaps clinically with both REM sleep behaviour disorder and post-traumatic stress disorder [s2]. It is not an established diagnosis.

A cross-sectional study published in Sleep Medicine on September 13 applies the proposed criteria to 99 Ukrainian combatants receiving inpatient treatment for stress-related disorders, and finds that the great majority meet them [s1].

What was done

The study enrolled 99 male combatants aged 18 to 59 who were inpatients for stress-associated disorders: 36 with adjustment disorder and 63 with post-traumatic stress disorder, diagnosed by psychiatric interview against ICD-10 criteria [s1].

Assessment used the Insomnia Severity Index, the Hamburg Nightmare Questionnaire, and a trauma-associated sleep disorder symptom assessment [s1]. There was no polysomnography, so "probable" is the operative word throughout — the disruptive nocturnal behaviours central to the proposed criteria were established by report, not by recording [s1].

The findings

Clinically significant insomnia was present in 77.8% of participants with adjustment disorder and 82.5% of those with PTSD, a difference that was not statistically significant (p = 0.562) [s1]. Nightmares were reported by 86.1% and 90.5% respectively (p = 0.533) [s1].

Probable trauma-associated sleep disorder criteria were met by 80.6% of the adjustment disorder group and 84.1% of the PTSD group (p = 0.650) [s1].

Combatants with clinically significant insomnia had 2.55 times the risk of probable trauma-associated sleep disorder compared with those without insomnia (RR 2.55, 95% CI 1.41 to 4.60, p < 0.001), a relationship that persisted after adjustment for confounding factors [s1].

The one interesting comparison in the data

None of the three prevalence figures differed meaningfully between adjustment disorder and PTSD. That is the finding worth sitting with. If the proposed parasomnia were tracking PTSD, one would expect separation between a group with the full PTSD diagnosis and a group with a milder stress-related disorder. Here there was none — the p-values for all three comparisons are between 0.53 and 0.65 [s1].

Two readings are available. The generous one is that trauma-associated sleep disorder is a trauma-exposure phenomenon rather than a PTSD phenomenon, which is what its proponents argue: the 2018 review positions the inciting traumatic experience, not the psychiatric diagnosis, as definitional [s2]. The sceptical one is that criteria satisfied by more than 80% of an inpatient population regardless of their diagnosis may not be discriminating between much of anything.

With 36 participants in one arm, the study is also underpowered to detect a difference of the size that might exist. A non-significant p-value here is weak evidence of no difference.

What the design cannot support

This is a cross-sectional study of hospitalised patients — the most severely affected end of the population — so the prevalence figures do not describe combatants generally, and certainly not trauma-exposed civilians. It is a single-country sample of 99 men, with no women [s1].

The association between insomnia and probable trauma-associated sleep disorder is at risk of being partly definitional. Insomnia features in the proposed conception of the disorder: the 2018 review describes hyperarousal as a component that likely contributes to comorbid insomnia [s2]. A relative risk of 2.55 between two overlapping constructs measured by questionnaire in the same sitting is not the same as a prospective finding.

There is no polysomnography, which is precisely what would distinguish the proposed parasomnia from PTSD nightmares — the 2018 review's central difficulty was the small number of laboratory-documented cases [s2], and this study does not add any.

Why it still matters

Ukraine has a very large population of combatants with recent trauma exposure and an under-resourced sleep-medicine infrastructure. The study's practical suggestion is narrow and plausible: insomnia, which is cheap to screen for with a short questionnaire, may serve as a marker identifying who warrants closer assessment of trauma-related nocturnal symptoms [s1]. That holds whether or not the proposed parasomnia is eventually accepted as a distinct entity.

What to watch

Whether polysomnographic series from this or comparable populations document the REM-atonia abnormality the proposed criteria rest on; whether the disorder is taken up in diagnostic classifications; and whether treatment trials targeting nightmares and nocturnal behaviours separately from PTSD show distinct effects.

This article describes a cross-sectional questionnaire study and is informational only. It is not medical advice and does not recommend any assessment or treatment.