The prevalence of Dissociative Disorders and dissociative experiences in college populations: a meta-analysis of 98 studies.

This meta-analysis of 31,905 college students includes 12 studies diagnosing Dissociative Disorders (DD) and 92 studies measuring dissociation with the Dissociative Experiences Scale (DES). Prevalence rates were used to separately test the plausibility of the Trauma Model (TM) and the Fantasy Model (FM) of dissociation. Results show 11.4% of students sampled meet criteria for DD, which is consistent with the prevalence of experiencing multiple (types of) trauma during childhood (12%), but is not consistent with the very low prevalence expected from the role of fantasy-proneness proposed in the FM. DES scores varied significantly across the 16 countries and were not higher in North America, but in countries that were comparatively unsafe. The least well-known DD was the most common, which is inconsistent with the FM which holds that the diagnosed person is enacting a familiar social role. There was no evidence that DES scores had decreased over recent decades, which does not support FM assertions that DD were a fad of the 1990s. Three of the five hypotheses tested provided clear support for the TM and a fourth hypothesis provided partial support for the TM. None of the five hypotheses tested supported the FM. The finding that DD were slightly more common in college populations than the general population did not support predictions of either model. The theoretical perspective of the authors moderated DES scores, although this is unlikely due to experimenter bias as studies led by FM theorists had significantly higher DES scores than those led by TM theorists.

Anticipatory Traumatic Reaction: Outcomes Arising From Secondary Exposure to Disasters and Large-Scale Threats.

Two studies, with a total of 707 participants, developed and examined the reliability and validity of a measure for anticipatory traumatic reaction (ATR), a novel construct describing a form of distress that may occur in response to threat-related media reports and discussions. Exploratory and confirmatory factor analysis resulted in a scale comprising three subscales: feelings related to future threat; preparatory thoughts and actions; and disruption to daily activities. Internal consistency was .93 for the overall ATR scale. The ATR scale demonstrated convergent validity through associations with negative affect, depression, anxiety, stress, neuroticism, and repetitive negative thinking. The scale showed discriminant validity in relationships to Big Five characteristics. The ATR scale had some overlap with a measure of posttraumatic stress disorder, but also showed substantial separate variance. This research provides preliminary evidence for the novel construct of ATR as well as a measure of the construct. The ATR scale will allow researchers to further investigate anticipatory traumatic reaction in the fields of trauma, clinical practice, and social psychology.

A meta-analytic investigation of the impact of mindfulness-based interventions on post traumatic stress.

A number of studies have investigated the impact of mindfulness-based interventions on symptoms of post-traumatic stress (PTSD) compared to control conditions. The current meta-analysis consolidated findings from 18 studies reporting results for 21 samples of participants. Across studies, mindfulness-based treatments compared to control conditions were effective in ameliorating symptoms of PTSD, with Hedges' g=-0.44. Hedges' g was -0.59 for comparison of mindfulness-based interventions to waitlist control conditions. Changes in mindfulness may underpin the effect of mindfulness-based interventions on PTSD symptoms and thus the meta-analysis examined findings regarding increases in mindfulness. The 12 studies that assessed mindfulness found that the interventions significantly increased mindfulness, Hedges' g=0.52. Moderator analyses indicated that interventions with longer mindfulness training were more efficacious in reducing symptoms of PTSD. Across studies, gender, age, veteran status, or length of time between the intervention and assessment of PTSD symptoms did not moderate the impact of mindfulness-based interventions. The results provide a foundation for future research directions and have implications for work with those impacted by trauma.