Abstract The present study compared the utility of categorical (i.e., diagnostic status) and dimensional (i.e., symptom severity) approaches to measuring posttraumatic stress disorder (PTSD) in predicting future suicide attempts among participants in a nationwide, longitudinal study of U.S. military veterans who were deployed in support of operations in Iraq or Afghanistan after the September 11, 2001, terrorist attacks (9/11) and were enrolled in Veterans Health Administration services ( N = 1,649). Following an initial assessment of PTSD symptoms, we assessed for suicide attempts at two subsequent time points ( M = 28.74 months, SD = 8.72 and M = 55.11 months, SD = 6.89 following the initial assessment). Between the initial and final assessments, 125 participants (7.58%) made at least one suicide attempt. All categorical and dimensional indicators of PTSD predicted suicide attempts at both time points except the categorical indicator for reexperiencing symptoms. Categorical indicators predicting suicide attempts demonstrated excellent sensitivity but poor specificity and overall accuracy. The point along the continuum at which PTSD symptom severity was most accurate regarding the prediction of future suicide attempts was well above the threshold previously established as indicating a probable diagnosis. Although this score was less sensitive than diagnostic indicators, it demonstrated greater specificity and overall accuracy in predicting future suicide attempts. The present results indicate that veterans whose PTSD symptoms satisfy the diagnostic criteria have a higher risk of future suicide attempts, but this risk appears to be even higher for veterans with symptom levels above the diagnostic threshold.
Several known risk factors for nonsuicidal self-injury (NSSI), such as negative emotionality and deficits in emotion skills, are also associated with masculinity. Researchers and clinicians suggest that masculine norms around emotional control and self-reliance may make men more likely to engage in self-harm. Masculinity has also been implicated as a potential risk factor for suicide and other self-damaging behaviors. However, the association between masculinity and NSSI has yet to be explored. In the current study, a sample of 912 emerging adults from two universities in the Northeastern United States completed a web-based questionnaire assessing adherence to masculine norms, engagement in NSSI, and known risk factors for NSSI (demographics and number of self-injurers known). Stronger adherence to masculine norms predicted chronic NSSI (five or more episodes throughout the life span) above and beyond other known risk factors. Adherence to masculine norms was related to methods of NSSI. Clinical implications are discussed, including discussions of masculine norms in treatment settings. Future research should examine what specific masculine norms are most closely linked to NSSI and other self-damaging behaviors.
Suicide is a leading cause of death worldwide.Despite decades of clinical and theoretical accounts that suggest that suicidal thoughts and behaviors are efforts to escape painful emotions, little prior research has examined decision making involved in escaping aversive states.We compared the performance of 85 suicidal participants to 44 nonsuicidal psychiatric patients on a novel reinforcement learning task with choices to make either active (i.e., "go") or passive responses (i.e., "no-go") to either escape or avoid an aversive stimulus.We used a computational cognitive model to isolate decision-making biases.We hypothesized that suicidal participants would exhibit a relatively elevated bias for making active responses to escape an aversive state and would show worse performance when escape required a passive response (i.e., "doing nothing" to escape).Our hypotheses were supported: The computational model revealed that suicidal participants exhibited a higher bias for an active response to escape compared with nonsuicidal psychiatric controls, suggesting that this finding was not just the result of the presence of psychopathology.The bias parameter also accounted for unique variance in predicting group status among several constructs previously related to suicidal thoughts and behaviors.This study provides a new method for testing escape decision making and does so using a computational cognitive model, allowing us to precisely index processes underlying suicidal and related behaviors.Future research examining escape decision making from a computational perspective could help link neural processes or environmental stressors to suicidal thoughts or behaviors.
Self-injurious thoughts and behaviors (SITBs) are a growing concern among youth in sub-Saharan Africa, but their prevalence and correlates in this region are poorly understood. We therefore examined self-reported SITBs in a population-representative sample of youth in rural Burkina Faso. We used interviews from 1,538 adolescents aged 12 to 20 years living in 10 villages and 1 town in northwestern Burkina Faso. Adolescents were asked about their experiences with suicidal and nonsuicidal SITBs, adverse environmental factors, psychiatric symptoms, and interpersonal-social experiences. SITBs included lifetime prevalence of life is not worth living, passive suicide ideation, active suicide ideation, and nonsuicidal self-injury (NSSI). After describing SITB prevalence, we ran logistic and negative binomial regression models to predict SITBs. Weighted lifetime SITB prevalence estimates were: 15.6% (95% confidence interval [CI]: 13.7–18.0) for NSSI; 15.1% (95% CI: [13.2, 17.0]) for life is not worth living; 5.0% (95% CI [3.9, 6.0]) for passive suicide ideation; and 2.3% (95% CI [1.6, 3.0]) for active suicide ideation. Prevalence of life is not worth living increased with age. All four SITBs were significantly positively associated with mental health symptoms (depression symptoms, probable posttraumatic stress disorder) and interpersonal-social experiences (peer and social connectedness, physical assault, sexual assault and unwanted sexual experiences). Females were significantly more likely to report that their life was not worth living compared to males (aOR = 0.68; 95% CI [0.48, 0.96]). There is a high prevalence of SITBs among youth in rural Burkina Faso, most notably NSSI and life is not worth living, with interpersonal-social factors being the strongest predictors. Our results highlight the need for longitudinal SITB assessment to understand how risk for SITBs operates in resource-constrained settings, and to design interventions to mitigate risk. Given low school enrollment in rural Burkina Faso, it will be important to consider youth suicide prevention and mental health initiatives that are not school-based.
Habitat loss and fragmentation often result in small, isolated populations vulnerable to environmental disturbance and loss of genetic diversity. Low genetic diversity can increase extinction risk of small populations by elevating inbreeding and inbreeding depression, and reducing adaptive potential. Due to their linear nature and extensive use by humans, freshwater ecosystems are especially vulnerable to habitat loss and fragmentation. Although the effects of fragmentation on genetic structure have been extensively studied in migratory fishes, they are less understood in low-mobility species. We estimated impacts of instream barriers on genetic structure and diversity of the low-mobility river blackfish (Gadopsis marmoratus) within five streams separated by weirs or dams constructed 45–120 years ago. We found evidence of small-scale (<13 km) genetic structure within reaches unimpeded by barriers, as expected for a fish with low mobility. Genetic diversity was lower above barriers in small streams only, regardless of barrier age. In particular, one isolated population showed evidence of a recent bottleneck and inbreeding. Differentiation above and below the barrier (FST = 0.13) was greatest in this stream, but in other streams did not differ from background levels. Spatially explicit simulations suggest that short-term barrier effects would not be detected with our data set unless effective population sizes were very small (<100). Our study highlights that, in structured populations, the ability to detect short-term genetic effects from barriers is reduced and requires more genetic markers compared to panmictic populations. We also demonstrate the importance of accounting for natural population genetic structure in fragmentation studies.
