Is Cumulative Exposure to Suicide Attempts and Deaths a Risk Factor for Suicidal Behavior Among Firefighters? A Preliminary Study

The association between cumulative exposure to suicide attempts and deaths and suicidal behavior was examined in a sample of 61 professional firefighters. On average, firefighters reported 13.1 (SD = 16.6) exposures over the course of their lifetime. Cumulative exposure to suicide attempts and deaths was positively correlated with suicidal behavior (r = .38, p = .004). Moreover, firefighters with 12+ exposures were more likely to screen positive for risk of suicidal behavior (OR = 7.885, p = .02). Additional research on the potential impact of cumulative exposure to suicide attempts and deaths on firefighters' health and safety is needed.     

Suicidal Ideation, Depression, and Conduct Disorder in a Sample of Adolescent and Young Adult Twins

The co-occurrence of suicidal ideation, depression, and conduct disturbance is likely explained in part by correlated genetic and environmental risk factors. Little is known about the specific nature of these associations. Structured interviews on 2,814 twins from the Virginia Twin Study of Adolescent Behavioral Development (VTSABD) and Young Adult Follow-Up (YAFU) yielded data on symptoms of depression, conduct disorder, and adolescent and young adult suicidal ideation. Univariate analyses revealed that the familial aggregation for each trait was explained by a combination of additive genetic and shared environmental effects. Suicidal ideation in adolescence was explained in part by genetic influences, but predominantly accounted for by environmental factors. A mixture of genetic and shared environmental influences explained ideation occurring in young adulthood. Multivariate analyses revealed that there are genetic and shared environmental effects common to suicidal ideation, depression, and conduct disorder. The association between adolescent suicidal ideation and CD was attributable to the same genetic and environmental risk factors for depression. These findings underscore that prevention and intervention strategies should reflect the different underlying mechanisms involving depression and conduct disorder to assist in identifying adolescents at suicidal risk.     

Action experience in infancy predicts visual-motor functional connectivity during action anticipation

Despite substantial evidence indicating a close link between action production and perception in early child development, less is known about how action experience shapes the processes of perceiving and anticipating others’ actions. Here, we developed a novel approach to capture functional connectivity specific to certain brain areas to investigate how action experience changes the networks involved in action perception and anticipation. Nine- and-12-month-old infants observed familiar (grasping) and novel (tool-use) actions while their brain activity was measured using EEG. Infants’ motor competence of both actions was assessed. A link between action experience and connectivity patterns was found, particularly during the anticipation period. During action anticipation, greater motor competence in grasping predicted greater functional connectivity between visual (occipital alpha) and motor (central alpha) regions relative to global levels of whole-brain EEG connectivity. Furthermore, visual and motor regions tended to be more coordinated in response to familiar versus novel actions and for older than younger participants. Critically, these effects were not found in the control networks (frontal-central; frontal-occipital; parietal-central; parietal-occipital), suggesting a unique role of visual-motor networks on the link between motor skills and action encoding.

Highlights

• Infants’ motor development predicted functional connectivity patterns during action anticipation.
• Faster graspers, and older infants, showed a stronger ratio of visual-motor neural coherence.
• Overall whole-brain connectivity was modulated by age and familiarity with the actions.
• Measuring inter-site relative to whole-brain connectivity can capture specific brain-behavior links.
• Measures of phase-based connectivity over time are sensitive to anticipatory action.