The Influence of Transdiagnostic Vulnerability Factors on PTSD Symptom Clusters in a Veteran Sample.

BACKGROUND: There is continuing debate as to the latent structure underpinning posttraumatic stress disorder symptomatology. The transdiagnostic vulnerability factors of negative affect, anxiety sensitivity (and subcomponents) and intolerance of uncertainty have previously demonstrated the ability to explain symptom clusters in a range of anxiety and depressive disorders, and may give further understanding of PTSD symptomatology. METHOD: Within an Australian Defence Force veteran population, structural equation modeling is utilized to assess whether a hierarchical Original Model containing negative affect as the general cognitive factor, anxiety sensitivity and intolerance of uncertainty as mid-level factors, can explain variability among posttraumatic stress disorder symptom clusters as defined by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. A further hierarchical Anxiety Sensitivity Extended model consisting of the general cognitive factor of negative affect and the three sub-factors of anxiety sensitivity as mid-level factors was also tested upon PTSD symptom clusters. RESULTS: Both the hierarchical Original and Anxiety Sensitivity Extended models fit the data well. Within both models, negative affect consistently showed significant direct effects upon the posttraumatic stress disorder symptom clusters. In the Original Model, anxiety sensitivity served as a significant mediator of negative affect for several symptom clusters, while intolerance of uncertainty was non-significant both as a direct effect and as a mediator of negative affect. In the Anxiety Sensitivity Extended Model, the cognitive concerns sub-factor of anxiety sensitivity served as a significant mediator of negative affect for several symptom clusters, while the social and physical concerns sub-factors did not have significant direct or mediating effects. CONCLUSIONS: This study demonstrates a transdiagnostic hierarchical model significantly explains the severity of Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition posttraumatic stress disorder symptom constructs within a subclinical population. Negative affect and anxiety sensitivity can each be targeted with specific interventions, suggesting new avenues to augment current gold standard psychotherapeutic interventions.

Caring for the country: fatigue, sleep and mental health in Australian rural paramedic shiftworkers.

This study investigated sleep quality, fatigue, mental health and physical activity in rural paramedic shiftworkers. Although limited, previous studies have associated high fatigue levels and poorer health in this sector with shiftwork rostering and occupational demands. A modified version of the Standard Shiftwork Index was completed by 150 paramedics (117 male and 31 females) from rural Victoria. Single sample t tests found significantly higher levels of fatigue, depression, anxiety, and stress, and significantly poorer sleep quality than reference samples. Paramedics also reported less physical activity than community samples. By regression analysis, sleep quality explained the greatest amount of variance in fatigue scores, followed by depression and age. No gender differences in levels of depression or fatigue were found. Consistent with an earlier study of metropolitan paramedics based on the same methodology, findings suggest rural ambulance paramedic shiftworkers are at particular risk for increased levels of fatigue and depression (regardless of age or gender) and poor quality sleep. Organisational intervention was suggested.