Exploring the acute cardiovascular effects of Floatation-REST.

The central nervous system (CNS) exerts a strong regulatory influence over the cardiovascular system in response to environmental demands. Floatation-REST (Reduced Environmental Stimulation Therapy) is an intervention that minimizes stimulation from the environment, yet little is known about the autonomic consequences of reducing external sensory input to the CNS. We recently found that Floatation-REST induces a strong anxiolytic effect in anxious patients while paradoxically enhancing their interoceptive awareness for cardiorespiratory sensations. To further investigate the physiologic nature of this anxiolytic effect, the present study measured acute cardiovascular changes during Floatation-REST using wireless and waterproof equipment that allowed for concurrent measurement of heart rate, heart rate variability (HRV), breathing rate, and blood pressure. Using a within-subjects crossover design, 37 clinically anxious participants with high levels of anxiety sensitivity and 20 non-anxious comparison participants were randomly assigned to undergo a 90-min session of either Floatation-REST or an exteroceptive comparison condition that entailed watching a relaxing nature film. Measures of state anxiety and serenity were collected before and after each session, while indices of autonomic activity were measured throughout each session. HRV was calculated using both time-series and frequency domain analyses. Linear mixed-effects modeling revealed a significant main effect of condition such that relative to the film condition, Floatation-REST elicited significant decreases (p < 0.001) in diastolic blood pressure, systolic blood pressure, breathing rate, and certain metrics of HRV including the standard deviation of the interbeat interval (SDNN), low-frequency HRV, and very low-frequency HRV. Heart rate showed a non-significant trend (p = 0.073) toward being lower in the float condition, especially toward the beginning of the session. The only metric that showed a significant increase during Floatation-REST was normalized high-frequency HRV (p < 0.001). The observed physiological changes were consistent across both anxious and non-anxious participants, and there were no significant group by condition interactions. Blood pressure was the only cardiac metric significantly associated with float-related reductions in state anxiety and increases in serenity. These findings suggest that Floatation-REST lowers sympathetic arousal and alters the balance of the autonomic nervous system toward a more parasympathetic state. Clinical trial registration: [https://clinicaltrials.gov/show/NCT03051074], identifier [NCT03051074].

General distress is more important than PTSD's cognition and mood alterations factor in accounting for PTSD and depression's comorbidity.

BACKGROUND: Posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) are highly comorbid and exhibit strong correlations with each other at both the symptom level and latent factor level. Various theories have attempted to explain this relationship. Results have been inconsistent regarding whether PTSD's negative alterations in cognition and mood factor (NACM) is significantly more related to depression, in contrast to other factors of PTSD. METHODS: Confirmatory factor analysis was used to attempt to address the relationships between PTSD and MDD in a large sample of trauma-exposed combat veterans from the Ohio National Guard as part of a larger longitudinal study. RESULTS: Confirmatory factor analysis was used to test a bifactor model of PTSD symptoms, testing relations between PTSD's factors and a latent depressive factor. After partitioning out the common variance into the bifactor, we found that in contrast to other PTSD factors, PTSD's NACM factor was not significantly more related to depression. Instead, only the general bifactor predicted depressive symptoms. LIMITATIONS: The limitations of the present study include the following: the specific measures of PTSD and MDD used were based on self-report, and the sample consisted of non-clinical, non-treatment seeking veterans. CONCLUSIONS: The present study suggests that the high rate of comorbidity between posttraumatic stress disorder (PTSD) and major depressive disorder is more related to underlying general distress or negative affectivity than the symptom categories of the PTSD diagnostic criteria.

Latent dimensions of posttraumatic stress disorder and their relations with alcohol use disorder.

PURPOSE: The objective of this study was to evaluate the relationship between factors of posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) using confirmatory factor analysis (CFA) in order to further our understanding of the substantial comorbidity between these two disorders. METHODS: CFA was used to examine which factors of PTSD's dysphoria model were most related to AUD in a military sample. Ohio National Guard soldiers with a history of overseas deployment participated in the survey (n = 1215). Participants completed the PTSD Checklist and a 12-item survey from the National Survey on Drug Use used to diagnosis AUD. RESULTS: The results of the CFA indicated that a combined model of PTSD's four factors and a single AUD factor fit the data very well. Correlations between PTSD's factors and a latent AUD factor ranged from correlation coefficients of 0.258-0.285, with PTSD's dysphoria factor demonstrating the strongest correlation. However, Wald tests of parameter constraints revealed that AUD was not more correlated with PTSD's dysphoria than other PTSD factors. CONCLUSIONS: All four factors of PTSD's dysphoria model demonstrate comparable correlations with AUD. The role of dysphoria to the construct of PTSD is discussed.

Latent profile analyses of posttraumatic stress disorder, depression and generalized anxiety disorder symptoms in trauma-exposed soldiers.

Posttraumatic stress disorder (PTSD) is comorbid with major depressive disorder (MDD; Kessler et al., 1995) and generalized anxiety disorder (GAD; Brown et al., 2001). We aimed to (1) assess discrete patterns of post-trauma PTSD-depression-GAD symptoms using latent profile analyses (LPAs), and (2) assess covariates (gender, income, education, age) in defining the best fitting class solution. The PTSD Checklist (assessing PTSD symptoms), GAD-7 scale (assessing GAD symptoms), and Patient Health Questionnaire-9 (assessing depression) were administered to 1266 trauma-exposed Ohio National Guard soldiers. Results indicated three discrete subgroups based on symptom patterns with mild (class 1), moderate (class 2) and severe (class 3) levels of symptomatology. Classes differed in symptom severity rather than symptom type. Income and education significantly predicted class 1 versus class 3 membership, and class 2 versus class 3. In conclusion, there is heterogeneity regarding severity of PTSD-depression-GAD symptomatology among trauma-exposed soldiers, with income and education predictive of class membership.

Posttraumatic stress disorder's dysphoria dimension and relations with generalized anxiety disorder symptoms.

The present study investigated symptom relations between two highly comorbid disorders--posttraumatic stress disorder (PTSD) and generalized anxiety disorder (GAD)--by exploring their underlying dimensions. Based on theory and prior empirical research it was expected that the dysphoria factor of PTSD would be more highly related to GAD. As part of a longitudinal project of mental health among Ohio National Guard Soldiers, 1266 subjects were administered the Posttraumatic Stress Disorder Checklist (PCL) and Generalized Anxiety Disorder-7 scale (GAD-7). Confirmatory factor analyses (CFAs) were conducted to examine two models of PTSD and to determine which PTSD factors were more related to the GAD factor. The results indicate that the GAD factor was significantly more highly correlated with PTSD's dysphoria factor than with all other PTSD factors, including PTSD's reexperiencing factor, avoidance factor, and hyperarousal factor. Results indicate GAD was not significantly more highly correlated with numbing than most other factors of PTSD. The results are consistent with prior research. Implications of the results are discussed in regards to PTSD in DSM-5, comorbidity and diagnostic specificity.

Structural relations between DSM-5 PTSD and major depression symptoms in military soldiers.

BACKGROUND: Posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) are frequently comorbid. One explanation for this comorbidity is that PTSD has a constellation of "dysphoria" symptoms resembling depression. METHOD: Using confirmatory factor analysis we tested the role of DSM-5 PTSD׳s dysphoria factor in relation to MDD symptom dimensions of somatic and non-somatic psychopathology. 672 Ohio National Guard soldiers completed DSM-5 measures of PTSD and MDD symptoms in an epidemiological study. RESULTS: Results indicated that in contrast to other PTSD factors, PTSD׳s dysphoria factor was more related to MDD׳s somatic and non-somatic factors. LIMITATIONS: Limitations include generalizability to the epidemiological population of trauma-exposed military veterans rather than civilians, and reliance on self-report measures. CONCLUSIONS: Implications concerning clinical psychopathology and comorbidity of PTSD are discussed, including whether PTSD should be refined by removing its non-specific symptoms.

Validation of the telephone-administered PHQ-9 against the in-person administered SCID-I major depression module.

BACKGROUND: We assessed item-to-item correspondence between the Patient Health Questionnaire-9 (PHQ-9) and the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I) major depression episode portion of the major depressive module. METHOD: Four hundred and ninety-eight soldiers in the Ohio National Guard were administered the PHQ-9 and SCID-I. Data were analyzed using chi-square analyses, logistic regression, receiver operating characteristic (ROC) curve analyses and diagnostic efficiency statistics. RESULTS: To screen for depression effectively, results indicate use of the cardinal first two items, items representing fatigue, appetite and sleep changes with an item level cut-off point of two, and the item representing suicidal ideation with item level cut-off point of one. Further, total PHQ-9 scores significantly predicted SCID-I major depressive episode (MDE) and diagnosis (MDD) with moderate accuracy. Lastly, the cut-off total score of 10 had the optimal balance of sensitivity and specificity compared to other PHQ-9 scoring options. LIMITATIONS: Differences in timeline of administration of the measures, differences in "worst episode" reference between the measures, and use of a specific military population are some of the limitations. CONCLUSIONS: This validation study provides guidelines for the use of the telephone-administered PHQ-9 in assessing the lifetime prevalence of a major depressive episode and diagnosis in non-clinical populations, with implications for clinical use.

Relations between the underlying dimensions of PTSD and major depression using an epidemiological survey of deployed Ohio National Guard soldiers.

BACKGROUND: In the present study, the authors investigated the relationship between the underlying symptom dimensions of posttraumatic stress disorder (PTSD) and dimensions of major depressive disorder (MDD). METHOD: A sample of 1266 Ohio National Guard soldiers with a history of overseas deployment participated and were administered the PTSD Checklist (assessing PTSD) and Patient Health Questionnaire-9 (assessing depression). RESULTS: Using confirmatory factor analysis, results demonstrated that both PTSD's dysphoria and hyperarousal factors were more related to depression's somatic than non-somatic factor. Furthermore, depression's somatic factor was more related to PTSD's dysphoria than hyperarousal factor. LIMITATIONS: Limitations of this study include the use of self-report measures and a predominately male military sample. CONCLUSIONS: Results indicate that PTSD's dysphoria factor is related to depression specifically by way of depression's somatic construct. Given PTSD's substantial dysphoria/distress component, these results have implications for understanding the nature of PTSD's high comorbidity with depression.

The factor structure of major depression symptoms: a test of four competing models using the Patient Health Questionnaire-9.

Little research has examined the underlying symptom structure of major depressive disorder (MDD) symptoms based on DSM-IV criteria. Our aim was to analyze the symptom structure of major depression, using the Patient Health Questionnaire-9 (PHQ-9). The PHQ-9 was administered to a sample of 2615 Army National Guard soldiers from Ohio. A one-factor model of depression and three separate two-factor models previously established in the literature were evaluated using confirmatory factor analysis. Results demonstrated greater support for the two-factor models of depression than for the one-factor model. The best fitting model was the two-factor model of somatic and non-somatic symptoms supported previously by Krause et al. (2010) and Richardson and Richards (2008). Implications for understanding the components and mechanisms of MDD are discussed.

Measurement differences from rating posttraumatic stress disorder symptoms in response to differentially distressing traumatic events.

The authors explored differences in posttraumatic stress disorder (PTSD) symptoms as a result of rating symptoms from two separate, differentially distressing traumatic events. In an initial sample of 400 nonclinical participants, the authors inquired through a web survey about previous psychological trauma, instructing participants to nominate their most distressing and second most distressing traumatic events experienced. Using the PTSD Checklist, participants rated their PTSD symptoms separately from these worst and second worst events. Using the four-factor emotional numbing PTSD model in confirmatory factor analysis, results demonstrated evidence supporting separation of PTSD symptom rating sets from two differentially distressing traumas-specifically, the worst and second worst events. Measurement invariance tests revealed that factor loadings did not vary between the worst and second worst event PTSD ratings; item thresholds (indexing symptom severity) differed. Results generally support the recommended PTSD assessment protocol instructing participants to rate PTSD symptoms from a single, worst index event.

PTSD factor structure differences between veterans with and without a PTSD diagnosis.

This study examined differences in posttraumatic stress disorder's (PTSD) factor structure between veterans with and without a PTSD diagnosis. An archival dataset of 378 trauma-exposed Canadian veterans (mostly men) was used. The sample was divided into participants who met DSM-IV criteria for PTSD (n=230) and those who did not (n=148), based on a structured diagnostic interview. Confirmatory factor analysis was conducted to determine which empirically supported four-factor PTSD model best fit the data: (1) King, Leskin, King, and Weathers' (1998) Emotional Numbing model of Reexperiencing, Avoidance, Emotional Numbing and Hyperarousal factors, or (2) Simms, Watson, and Doebbeling's (2002) Dysphoria model of Reexperiencing, Avoidance, Dysphoria, and Hyperarousal factors. Results indicated that both models fit slightly better in the No-PTSD group. A series of measurement invariance tests demonstrated that the two groups varied on all parameters with the exception of factor loadings. The PTSD-group had larger intercepts, factor means, and residual error variance, suggesting that these participants had greater PTSD severity but more measurement error associated with their PTSD ratings. This study contributes to our understanding of how a PTSD diagnosis impacts the structure of PTSD symptoms at the latent level.