δEPCD: the electrophysiologic coefficient of depressiveness

Despite research advances, recently identified biological markers for depression are either non-specific or impractical in daily clinical practice. Hence, we aim to identify a novel biomarker: δ_EPCD, the electrophysiologic coefficient of depressiveness. δ_EPCD must be sensitive and specific to the vulnerability towards depression. It should also detect the presence of a depressive clinical state and be able to quantify its severity. Moreover, it should be easily accessible and cost-effective. Accordingly, combining high-frequency heart rate variability (HF-HRV), which reflects a reduction in vagal tone, and tryptophan metabolism, which influences serotonin synthesis pathway, may have a good diagnostic and prognostic accuracy in depression. δ_EPCD is the multiplication of the intrinsic difference between state 0 (rest) and state 1 (exposure to stress) of HF-HRV and the plasma concentration ratio between quinolinic acid and kynurenine. δ_EPCD theoretically fluctuates between -1000 and 0 where being closer to 0 signifies no vulnerability to depression. Individuals with a score between -16.7 and -167 have a high vulnerability to depression. Finally, individuals with a δ_EPCD closer to -1000 have the most severe forms of depression. δ_EPCD is theoretically conceived to be easy to assess and monitor which makes it a candidate for further evaluation of reliability and validity.CLINICAL SIGNIFICANCEDepression is currently diagnosed based on emotional and behavioural symptoms; however there is currently a rising interest in the field of neurobiological markers that could improve diagnostic accuracy.Many current biological approaches are primarily based on single neurobiological markers that are either non-specific or impractical in daily clinical practice.Among other neurological effects, depression may modify the parasympathetic nervous system tone and disturb the tryptophan metabolism.The electrophysiological coefficient of depressiveness δ_EPCD combines heart rate variability (HRV) and tryptophan metabolism to reflect the intrinsic individual vulnerability towards depression and the inherent severity of an index depressive disorder.δ_EPCD is the intrinsic difference between state 0 (without stress) and state 1 (exposed to a stressful task) of the high-frequency heart rate variability multiplied by the intrinsic difference between both states, e.g. state 0 and 1, of the plasma concentration ratio of quinolinic acid over kynurenine.

Trauma exposure and PTSD prevalence among Yazidi, Christian and Muslim asylum seekers and refugees displaced to Iraqi Kurdistan

BACKGROUND

There is unreliable, and negligible information on the mental health and trauma-exposure of asylum-seekers and displaced refugees in the Iraqi Kurdistan region.

OBJECTIVES

To evaluate how responsible the ethno-religious origins are, for the prevalence of trauma exposure and post-traumatic stress disorder (PTSD) in displaced Iraqi asylum-seekers and refugees residing in the Iraqi Kurdistan region.

METHODS

Structured interviews with a cross-sectional sample of 150 individuals, comprised of three self-identified ethno-religious groups (50 participants in each): Christians, Muslims, and Yazidis.

RESULTS

100% prevalence of trauma exposure and 48.7% of current PTSD among refugees, 70% PTSD rate of Yazidi participants, which is significantly higher (p < 0.01) compared to 44% of Muslim participants and 32% of Christian participants. These findings were corroborated using the self-rated PTSD, DSM-5 Checklist, with more severe PTSD symptom scores (p < 0.001) obtained among Yazidis (43.1; 19.7), compared to Muslims (31.3; 20.1) and Christians (29.3; 17.8). Self-rated depressive symptoms (Patient Health Questionnaire-9) were also higher (p < 0.007) among Yazidis (12.3; 8.2) and Muslims (11.7; 5.9), compared to Christians (8.1; 7).