Aversive response to uncertainty as a mediator for the effect of a mindfulness intervention on symptoms of anxiety.

THEORETICAL BACKGROUND: Intolerance of uncertainty plays a central role in anxiety and research suggests that it's an important treatment target. Investigating response to uncertainty using other dimensions than self-report, such as physiological responses, can further the effort to understand the role of uncertainty in anxiety more fully. Mindfulness interventions have become increasingly interesting in their application to anxiety, as they foster acceptance of unpleasant aspects of experience. The aims of the study were to examine whether a mindfulness intervention reduced response to uncertainty and anxiety symptoms, and to examine the associations between intolerance of uncertainty, physiological response to uncertainty, mindfulness and anxiety. METHODS: Participants were 117 students who completed a two-week mindfulness or audiobook control intervention. At pre- and post-intervention assessments, measures of anxiety, mindfulness, and intolerance of uncertainty were completed and a threat-of-shock task assessing startle responding to unpredictable shock was administered. RESULTS: Findings showed a significant effect of the intervention for social anxiety symptoms. Furthermore, intolerance of uncertainty mediated the effect of the intervention on symptoms for social anxiety and worry. No such effects were found for physiological response to uncertainty. CONCLUSION: The study adds to the understanding of the role of response to uncertainty in anxiety as well as to its mechanistic role in the context of mindfulness practice. Implications and possible explanations for the non-significant main effects of the intervention on anxiety symptoms and physiological response to uncertainty are discussed.

Longitudinal associations between hair cortisol, PTSD symptoms, and sleep disturbances in a sample of firefighters with duty-related trauma exposure.

Several studies have found evidence of altered cortisol levels in patients with posttraumatic stress disorder (PTSD). Based on these findings, it is assumed that these patients may show signs of cortisol dysregulation after trauma. Posttrauma cortisol levels are thus considered a potential biomarker of PTSD. However, longitudinal studies using indicators of long-term cortisol secretion such as hair cortisol concentrations (HCC) are scarce. The current study investigated prospective associations between HCC and PTSD symptoms in a sample of Dutch firefighters taking into account varying levels of work-related trauma severity. In addition, we assessed posttraumatic sleep disturbances as a secondary outcome measure to investigate whether effects generalize to this frequent comorbidity of PTSD. Three hundred seventy-one Dutch firefighters with a mean of 14.01 years of work experience were included in the analyses. Baseline assessment included the collection of hair samples and the measurement of work-related trauma severity, PTSD symptoms, and sleep disturbances. PTSD symptoms and sleep disturbance were re-assessed after six and twelve months. Multilevel analyses indicate a significant positive correlation between HCC and baseline PTSD symptoms in those with average or above-average work-related trauma severity. A similar pattern was evident for posttraumatic sleep disturbances at baseline. Moreover, higher HCC predicted more posttraumatic sleep disturbances after 6 months in participants with above-average work-related trauma severity. No other associations emerged for PTSD symptoms or posttraumatic sleep disturbances at six or twelve months. As such, our study supports the existence of a cross-sectional association between HCC and trauma symptoms, which may vary for different levels of subjective trauma severity. The longitudinal stability of this association should be reinvestigated by future research.

A prospective study of pre-trauma risk factors for post-traumatic stress disorder and depression.

BACKGROUND: It is unclear which potentially modifiable risk factors best predict post-trauma psychiatric disorders. We aimed to identify pre-trauma risk factors for post-traumatic stress disorder (PTSD) or major depression (MD) that could be targeted with resilience interventions. METHOD: Newly recruited paramedics (n = 453) were assessed for history of mental disorders with structured clinical interviews within the first week of their paramedic training and completed self-report measures to assess hypothesized predictors. Participants were assessed every 4 months for 2 years to identify any episodes of PTSD and MD; 386 paramedics (85.2%) participated in the follow-up interviews. RESULTS: In all, 32 participants (8.3%) developed an episode of PTSD and 41 (10.6%) an episode of MD during follow-up. In all but nine cases (2.3%), episodes had remitted by the next assessment 4 months later. At 2 years, those with episodes of PTSD or MD during follow-up reported more days off work, poorer sleep, poorer quality of life, greater burn-out; and greater weight-gain for those with PTSD. In line with theories of PTSD and depression, analyses controlling for psychiatric and trauma history identified several pre-trauma predictors (cognitive styles, coping styles and psychological traits). Logistic regressions showed that rumination about memories of stressful events at the start of training uniquely predicted an episode of PTSD. Perceived resilience uniquely predicted an episode of MD. CONCLUSIONS: Participants at risk of developing episodes of PTSD or depression could be identified within the first week of paramedic training. Cognitive predictors of episodes of PTSD and MD are promising targets for resilience interventions.