Understanding Heterogeneity in Ptsd: Fear, Dysphoria, and Distress

Attentional bias to threat is a key endophenotype that contributes to the chronicity of trauma-related psychopathology. However, little is known about the neurobiology of this endophenotype and no known in vivo molecular imaging study has been conducted to evaluate candidate receptor systems that may be implicated in this endophenotype or the phenotypic expression of trauma-related psychopathology that comprises threat (ie, re-experiencing, avoidance, and hyperarousal) and loss (ie, emotional numbing, depression/ dysphoria, generalized anxiety) symptomatology. Using the radioligand [ 11 C]OMAR and positron emission tomography (PET), we evaluated the relationship between in vivo cannabinoid receptor type 1 (CB 1 ) receptor availability in the amygdala, and performance on a dot-probe measure of attentional bias to threat, and clinician interview-based measures of trauma-related psychopathology. The sample comprised adults presenting with a broad spectrum of trauma-related psychopathology, ranging from nontrauma-exposed, psychiatrically healthy adults to trauma-exposed adults with severe trauma-related psychopathology. Results revealed that increased CB 1 receptor availability in the amygdala was associated with increased attentional bias to threat, as well as increased severity of threat, but not loss, symptomatology; greater peripheral anandamide levels were associated with decreased attentional bias to threat. A mediation analysis further suggested that attentional bias to threat mediated the relationship between CB 1 receptor availability in the amygdala and severity of threat symptomatology. These data substantiate a key role for compromised endocannabinoid function in mediating both the endophenotypic and phenotypic expression of threat symptomatology in humans. They further suggest that novel pharmacotherapies that target the CB 1 system may provide a more focused, mechanism-based approach to mitigating this core aspect of trauma-related psychopathology.

It has been well-documented that posttraumatic stress symptoms cause impairments in health-related quality of life (HRQoL). Until now we have little data on how DSM-5 PTSD symptom dimensions relate to different aspects of HRQoL. Clarifying this question would be informative to improve the quality of life of PTSD patients. This study aimed to investigate the effects of dimensions of a well-supported seven-factor model of DSM-5 PTSD symptoms on physical and psychosocial HRQoL. A total of 1063 adult survivors of the 2008 Wenchuan earthquake took part in this study nine years after the disaster. PTSD symptoms were measured by the PTSD Checklist for DSM-5 (PCL-5). HRQoL was measured by the Medical Outcomes Survey Short Form-36 (SF-36). The associations between PTSD symptom dimensions and HRQoL were examined using structural equation models. Dysphoric arousal symptoms were found to significantly relate to physical HRQoL. Other symptom dimensions were not associated with HRQoL. Our findings contribute to the relationship between DSM-5 PTSD and HRQoL, and carry implications for further clinical practice and research on trauma-exposed individuals.

This study examined the relationship between four factors of posttraumatic stress disorder symptoms -re-experiencing, avoidance, dysphoria and hyperarousal -and particular domains of emotional competence and emotional regulation and control among 215 Croatian Homeland War veterans. Cross-sectionally, emotional competence subscales -perceiving and understanding emotions, expressing and labelling emotions, managing and regulating emotions -were associated with dysphoria symptom cluster only, while emotional regulation and control subscalesinfluence of emotion and mood on memory and emotional reaction control -were associated with dysphoria and re-experiencing symptom clusters. The results of this study are consistent with the view that successful recovery from trauma requires adaptive emotion competence skills and that therefore difficulties in dealing with emotions (understanding, expressing or regulating) are a risk factor for the development and/or maintenance of posttraumatic stress disorder symptoms. It appears that interventions organized toward improving emotional competence and regulation may be useful as complementary or independent treatments for combat-related posttraumatic stress disorder.