David Bolton

Patterns of Suicidal Ideation and Behavior in Northern Ireland and Associations with Conflict Related Trauma

In this study, data from the World Mental Health Surveys Northern Ireland (NI) Study of Health and Stress (NISHS) was used to assess the associations between conflict- and non-conflict–related traumatic events and suicidal behaviour, controlling for age and gender and the effects of mental disorders in NI. DSM mental disorders and suicidal ideation, plans and attempts were assessed using the Composite International Diagnostic Interview (CIDI) in a multi-stage, clustered area probability household sample (N = 4,340, response rate 68.4%). The traumatic event categories were based on event types listed in the PTSD section of the CIDI. Suicidal ideation and attempts were more common in women than men, however, rates of suicide plans were similar for both genders. People with mood, anxiety and substance disorders were significantly more likely than those without to endorse suicidal ideation, plan or attempt. The highest odds ratios for all suicidal behaviors were for people with any mental disorder. However, the odds of seriously considering suicide were significantly higher for people with conflict and non-conflict–related traumatic events compared with people who had not experienced a traumatic event. The odds of having a suicide plan remain significantly higher for people with conflict-related traumatic events compared to those with only non-conflict–related events and no traumatic events. Finally, the odds of suicide attempt were significantly higher for people who have only non-conflict–related traumatic events compared with the other two categories. The results suggest that traumatic events associated with the NI conflict may be associated with suicidal ideation and plans, and this effect appears to be in addition to that explained by the presence of mental disorders. The reduced rates of suicide attempts among people who have had a conflict-related traumatic event may reflect a higher rate of single, fatal suicide attempts in this population.

A community study of the psychological effects of the Omagh car bomb on adults.

Background The main aims of the study were to assess psychological morbidity among adults nine months after a car bomb explosion in the town of Omagh, Northern Ireland and to identify predictors of chronic posttraumatic stress disorder symptoms. Method A questionnaire was sent to all adults in households in The Omagh District Council area. The questionnaire comprised established predictors of PTSD (such as pre-trauma personal characteristics, type of exposure, initial emotional response and long-term adverse physical or financial problems), predictors derived from the Ehlers and Clark (2000) cognitive model, a measure of PTSD symptoms and the General Health Questionnaire. Results Among respondents (n = 3131) the highest rates of PTSD symptoms and probable casesness (58.5%) were observed among people who were present in the street when the bomb exploded but elevated rates were also observed in people who subsequently attended the scene (21.8% probable caseness) and among people for whom someone close died (11.9%). People with a near miss (left the scene before the explosion) did not show elevated rates. Exposure to the bombing increased PTSD symptoms to a greater extent than general psychiatric symptoms. Previously established predictors accounted for 42% of the variance in PTSD symptoms among people directly exposed to the bombing. Predictors derived from the cognitive model accounted for 63%. Conclusions High rates of chronic PTSD were observed in individuals exposed to the bombing. Psychological variables that are in principle amenable to treatment were the best predictors of PTSD symptoms. Teams planning treatment interventions for victims of future bombings and other traumas may wish to take these results into account.

Targeting p35/Cdk5 Signalling via CIP-Peptide Promotes Angiogenesis in Hypoxia

Cyclin-dependent kinase-5 (Cdk5) is over-expressed in both neurons and microvessels in hypoxic regions of stroke tissue and has a significant pathological role following hyper-phosphorylation leading to calpain-induced cell death. Here, we have identified a critical role of Cdk5 in cytoskeleton/focal dynamics, wherein its activator, p35, redistributes along actin microfilaments of spreading cells co-localising with p(Tyr15)Cdk5, talin/integrin beta-1 at the lamellipodia in polarising cells. Cdk5 inhibition (roscovitine) resulted in actin-cytoskeleton disorganisation, prevention of protein co-localization and inhibition of movement. Cells expressing Cdk5 (D144N) kinase mutant, were unable to spread, migrate and form tube-like structures or sprouts, while Cdk5 wild-type over-expression showed enhanced motility and angiogenesis in vitro, which was maintained during hypoxia. Gene microarray studies demonstrated myocyte enhancer factor (MEF2C) as a substrate for Cdk5-mediated angiogenesis in vitro. MEF2C showed nuclear co-immunoprecipitation with Cdk5 and almost complete inhibition of differentiation and sprout formation following siRNA knock-down. In hypoxia, insertion of Cdk5/p25-inhibitory peptide (CIP) vector preserved and enhanced in vitro angiogenesis. These results demonstrate the existence of critical and complementary signalling pathways through Cdk5 and p35, and through which coordination is a required factor for successful angiogenesis in sustained hypoxic condition.

The Economic Burden of PTSD in Northern Ireland

The objective of this study was to estimate the economic costs of posttraumatic stress disorder (PTSD) among the Northern Ireland (NI) adult population. The authors present a prevalence-based, bottom-up study based primarily on data from 1,986 participants in the Northern Ireland Study of Health and Stress (NISHS). Both direct costs of treatment and indirect costs of productivity losses were included. Units of service and medication resource use were obtained from the NISHS and combined with their relevant unit costs from the Personal Social Services Research Unit and Prescription Costs Analysis data for NI. Indirect costs included the costs of incapacity days due to PTSD and presenteeism costs, with gender-specific wage rates used as the relevant unit costs. The total direct and indirect cost of PTSD in NI (2008) was £172,756,062. This figure is likely to be conservative due to the exclusion of a number of cost categories. Nevertheless, comparison of estimates of the burden of PTSD with the estimated cost of treating all adults with PTSD with the recommended treatments shows the potential for substantial economic gains to be made through extension and investment in effective evidence-based treatments.

Comparison of motor skill learning, grip strength and memory recall on land and in chest-deep water

Immersion in chest-deep water may augment explicit memory in healthy adults however, there is limited information on how this environment might affect implicit memory or motor learning. The purpose of this study was to compare the speed and accuracy for learning a motor skill on land and in chest-deep water. Verbal word recall and grip strength were included to gain a more complete understanding of the intervention. Sixty-two younger adults (age = 23.3 ± 3.59 yrs.) were randomly assigned to either a water group immersed to the xiphoid or a land group. Participants in both groups completed the same eight practice trials of a mirror-drawing task on two separate days. Outcome measures for this task included time and error numbers to complete each drawing. The number of words recalled using a 12 word recall test, and peak grip strength using a hand dynamometer were measured each day of testing. The influence of environment and repeated practice on each outcome measure were assessed with an analysis of variance and effect sizes (ES). Time and errors for both groups significantly decreased with practice (p < 0.01, ES = 0.11–0.28), however the drawing time was greater in water than on land for trials 1, 5, and 6 (ES = 0.50–0.55). There was a 7% increase in words recalled (9.24 ± 1.19 vs 8.60 ± 1.19) and a 16% increase in grip strength (405 ± 104 vs 342 ± 83) for water than land groups (ES 0.54–0.64). Healthy adults in chest-deep water and on land display comparable mirror-drawing speed and accuracy after minimal practice. Curiously, water immersion may augment verbal word recall and grip strength abilities.

Motor affordance for grasping a safety handle

Mere observation of objects in our surroundings can potentiate movement, a fact reflected by visually-primed activation of motor cortical networks. This mechanism holds potential value for reactive balance control where recovery actions of the arms or legs must be targeted to a new support base to avoid a fall. The present study was conducted to test if viewing a wall-mounted safety handle - the type of handle commonly used to regain balance - results in activation of motor cortical networks. We hypothesized that the hand area of the primary motor cortex would be facilitated shortly after visual access to a safety handle versus when no handle was visible. Here, we used transcranial magnetic stimulation (TMS) to measure corticospinal excitability in hand muscles directly following access to vision while participants performed a seated reach-grasp task. Vision was controlled using liquid crystal lenses and TMS pulses were time-locked to occur shortly after the goggles opened but prior to any cue for movement. Between trials the response environment was unpredictably altered to present either a handle or no handle (i.e. covered). Our results demonstrated a rapid motor facilitation in muscles of the right hand when participants viewed a handle versus trials where this handle was covered. This effect was selective both in terms of the muscles activated and the timing at which it emerged. The First Dorsal Interosseus and Opponens Pollicus muscles (synergists in closing the hand) were facilitated 120 ms after viewing the handle. Interestingly, this effect was absent at earlier (80 ms) and later (160 ms) points. Conversely, Abductor Digiti Minimi, which moves the little finger out from the rest of the hand, tended to diminish when viewing the handle. These findings suggest a rapid engagement of muscles suitable for grasping a handle based on vision. This is consistent with the concept of affordances where vision automatically translates viewed objects into appropriate motor terms. The fact that this affordance effect was present for a wall-mounted safety handle commonly used to regain balance has implications for automatically priming recovery actions with upper limbs suited to our surroundings, even before postural perturbation is detected.

Forecast or Fall: Prediction's Importance to Postural Control

To interact successfully with an uncertain environment, organisms must be able to respond to both unanticipated and anticipated events. For unanticipated events, organisms have evolved stereotyped motor behaviors mapped to the statistical regularities of the environment, which can be trigged by specific sensory stimuli. These “reflexive” responses are more or less hardwired to prevent falls and represent, maybe, the best available solution to maintaining posture given limited available time and information. With the gift of foresight, however, motor behaviors can be tuned or prepared in advance, improving the ability of the organism to compensate for, and interact with, the changing environment. Indeed, foresights improvement of our interactive capacity occurs through several means, such as better action selection, processing, and conduction delay compensation and by providing a prediction with which to compare our actual behaviors to, thereby facilitating error identification and learning. Here we review the various roles foresight (prediction) plays in maintaining our postural equilibrium. We start by describing some of the more recent findings related to the prediction of instability. Specifically, we cover recent advancements in the understanding of anticipatory postural behaviors that are used broadly to stabilize volitional movement and compensate for impending postural disturbances. We also describe anticipatory changes in the state, or set, of the nervous system that may facilitate anticipatory behaviors. From changes in central set, we briefly discuss prediction of postural instability online before moving into a discussion of how predictive mechanisms, such as internal models, permit us to tune, perhaps our highest level predictive behaviors, namely the priming associated with motor affordances. Lastly, we explore methods best suited to expose the contribution of prediction to postural equilibrium control across a variety of contexts.

Vestibular vertical: a balancing act between the upper and lower limbs

Our vertical bipedal posture is one of the defining traits that separates us from our phylogenetic peers. Not surprisingly, the mechanisms underlying how we maintain this orientation have come under intense scientific scrutiny. This article is protected by copyright. All rights reserved