The nature of trauma memories in acute stress disorder in children and adolescents.

BACKGROUND: There is increasing theoretical, clinical and research evidence for the role of trauma memory in the aetiology of acute pathological stress responses in adults. However, research into the phenomenology of trauma memories in young people is currently scarce. METHODS: This study compared the nature of trauma narratives to narratives of unpleasant non-traumatic events in young people (aged 8-17) who sought emergency medical attention following an assault or road traffic accident. Data were collected within 2-4 weeks of the index event. Symptom severity was assessed by child self-report and face-to-face diagnostic interviews. Comparisons of narrative indices were made between those children with acute stress disorder (ASD) and those without ASD. RESULTS: Among participants (n = 50), those with ASD (38%) had significantly elevated levels of disorganisation in their trauma narrative, compared both to trauma-exposed controls and to their unpleasant comparative narrative. This effect was not accounted for by age. Regardless of ASD diagnostic status, trauma narratives had significantly higher sensory content and significantly lower positive emotion content compared to the unpleasant comparative narrative. These effects were not significant when age was included as a covariate. Acute symptom severity was significantly predicted by the level of disorganisation in the trauma narrative and the child's cognitive appraisals of the event. CONCLUSIONS: These data provide the first empirical evidence that disorganisation is not only directly linked to symptom severity, but also specific to the trauma memory. In addition, it provides support for the adaptation of adult cognitive models to acute pathological stress reactions in children and adolescents.

Semantic dementia and fluent primary progressive aphasia: two sides of the same coin?

Considerable controversy exists regarding the relationship between semantic dementia (SD) and progressive aphasia. SD patients present with anomia and impaired word comprehension. The widely used consensus criteria also include the need for patients to exhibit associative agnosia and/or prosopagnosia: many authors have used the label SD for patients with non-verbal, as well as verbal, semantic deficits on formal testing even if they recognize the objects and people encountered in everyday life; others interpret the criterion of agnosia to require pervasive recognition impairments affecting daily life. According to this latter view, SD patients have pathology that disrupts both a bilateral ventrotemporal-fusiform network (resulting in agnosia) and the left hemisphere language network (resulting in profound aphasia). These authors suggest that this profile is different to that seen in the fluent form of primary progressive aphasia (fPPA), a neurodegenerative disease primarily affecting language function. We present data on seven patients who met the diagnostic criteria for fPPA. All seven showed deficits relative to matched controls on both verbal and non-verbal measures of semantic memory, and these deficits were modulated by degree of anomia, concept familiarity and item typicality. Voxel-based morphometry revealed reduced grey matter density in the temporal lobes bilaterally (more widespread on the left), with the severity of atrophy in the left inferior temporal lobe being significantly related to performance on both the verbal and non-verbal measures. Together these findings suggest that patients who meet the diagnostic criteria for fPPA, can also meet the diagnostic criteria for early-stage SD provided that the impact of concept familiarity and typicality is taken into account. In addition, these findings support a claim that the patients' deficits on both verbal and non-verbal tasks reflect progressive deterioration of an amodal integrative semantic memory system critically involving the rostral temporal lobes, rather than a combination of atrophy in the left language network and a separate bilateral ventrotemporal-fusiform network.

Changes over time in cognitive and structural profiles of head injury survivors.

Survivors of traumatic head injury often suffer chronic cognitive deficits. Considerable evidence implicates the cholinergic system in these deficits. Recently, we reported cognitive and structural abnormalities in a cohort of head injured survivors consistent with this hypothesis [see Salmond, C. H., Chatfield, D. A., Menon, D. K., Pickard, J. D., & Sahakian, B. J. (2005). Cognitive Sequelae of Head Injury: Involvement of Basal Forebrain and associated structures. Brain, 128(1), 189-200]. The stability of the cognitive and structural MRI profiles was investigated in a longitudinal study. Twenty-one survivors of moderate-severe head injury completed two comprehensive neuropsychological assessments and two structural MRI scans at least six months apart. A cohort of controls also completed these investigations. The results revealed that the cognitive and structural profiles are relatively stable from six months post-injury forward up to 3 years post-injury. Deficits in memory, attention and reaction time were found, with relative preservation of working memory, consistent with abnormalities in the cholinergic system. These findings suggest that cholinergic enhancers may be an effective treatment for cognitive deficits post-head injury in survivors up to three years post-injury.

Cognitive sequelae of head injury: involvement of basal forebrain and associated structures.

Traumatic brain injury is the most common cause of death and disability in young people and survivors often suffer from chronic cognitive deficits. From animal, post-mortem and cognitive studies, there is now increased evidence that abnormalities in the cholinergic system may be underlying some of these deficits. This study investigated this hypothesis in a group of survivors of moderate-severe head injury (n = 31). Patients completed a comprehensive neuropsychological assessment and an MRI scan. Compared with a group of controls (matched on age, sex and premorbid intelligence quotient), the patients showed deficits in sustained attention, paired associate learning and reaction time, but comparative preservation of spatial working memory. Voxel-based morphometry revealed reduced grey matter density in the head injured group in the basal forebrain, the hippocampal formation and regions of the neocortex. These cognitive and structural results are consistent with cholinergic dysfunction. These preliminary findings suggest that cholinergic enhancers may be an effective treatment of cognitive deficits post head injury.

Deficits in decision-making in head injury survivors.

Many survivors of head injury suffer chronic personality changes, such as increased impulsivity and a lack of insight and poor judgment. These changes are well recognized and likely to affect the ability to make decisions. However, systematic investigations into their nature have been limited. This study aims to explore the nature of decision making in head injury survivors using a computerized task. Forty-three head injury survivors and a group of 29 matched controls completed the computerized task. The task required participants to make a probability-based choice and to further qualify this choice with an associated "bet." This betting component allows an assessment of the participant's level of confidence in the decision, via the affective evaluation of its possible consequences in terms of points won or lost. The survivors were found to be slow at making the probability- based choice. Whilst at highly favorable odds, the survivors chose the most likely option in a similar manner to the controls, they chose the most likely option less often than the controls at less favorable odds. Examination of the survivors' betting behavior revealed that they responded impulsively compared to controls. This pattern of prolonged decision making and poor quality of decisions is similar to that found in patients with orbitofrontal cortex lesions, whilst impulsive betting has been associated with abnormalities of the dopamine system. These complex deficits in decision making may contribute to difficulties with poor judgment and inhibition in head injury survivors.

Imaging of cerebral blood flow and metabolism in brain injury in the ICU.

The heterogeneity of the initial insult and subsequent pathophysiology has made both the study of human head injury and design of randomised controlled trials exceptionally difficult. The combination of multimodality bedside monitoring and functional brain imaging positron emission tomography (PET) and magnetic resonance (MR), incorporated within a Neurosciences Critical Care Unit, provides the resource required to study critically ill patients after brain injury from initial ictus through recovery from coma and rehabilitation to final outcome. Methods to define cerebral ischemia in the context of altered cerebral oxidative metabolism have been developed, traditional therapies for intracranial hypertension re-evaluated and bedside monitors cross-validated. New modelling and analytical approaches have been developed.

Is platelet imipramine binding reduced in depression? A meta-analysis.

Although it has been suggested that decreased platelet imipramine binding may be a putative biological marker of depressive illness, a number of studies have not confirmed this finding, including a recent multicenter investigation by the World Health Organization (Mellerup and Langer 1990). We performed a meta-analysis of published reports on imipramine binding in groups of depressed and healthy control subjects and found that there was a highly significant decrease in Bmax (maximal binding) values in the depressed subject groups, which was even greater among those who had been free of medication for 4 weeks at the time of investigation. This finding remained highly significant even when only high affinity binding studies (Kd < 1 nmol/L) were considered, although the absolute size of this decrease was smaller.

Cholesterol, coconuts, and diet on Polynesian atolls: a natural experiment: the Pukapuka and Tokelau island studies.

Two populations of Polynesians living on atolls near the equator provide an opportunity to investigate the relative effects of saturated fat and dietary cholesterol in determining serum cholesterol levels. The habitual diets of the toll dwellers from both Pukapuka and Tokelau are high in saturated fat but low in dietary cholesterol and sucrose. Coconut is the chief source of energy for both groups. Tokelauans obtain a much higher percentage of energy from coconut than the Pukapukans, 63% compared with 34%, so their intake of saturated fat is higher. The serum cholesterol levels are 35 to 40 mg higher in Tokelauans than in Pukapukans. These major differences in serum cholesterol levels are considered to be due to the higher saturated fat intake of the Tokelauans. Analysis of a variety of food samples, and human fat biopsies show a high lauric (12:0) and myristic (14:0) content. Vascular disease is uncommon in both populations and there is no evidence of the high saturated fat intake having a harmful effect in these populations.

Trends in amenable mortality in New Zealand 1968-1987.

Trends in amenable mortality rates for Maori and non-Maori New Zealanders were analysed and compared using regression models. The contribution of medical services to the decline in mortality rates was estimated. Mortality from causes amenable to medical intervention declined at a greater rate than non-amenable mortality for both groups. The proportion of the decline in mortality attributable to improvement in the impact of medical services was greater for non-Maori than for Maori, especially for females. Maori to non-Maori mortality ratios were greater for amenable than for non-amenable causes, indicating a systematic differential between the two groups in the impact of medical services. There was only a small improvement over the 20 years in the excess of amenable mortality suffered by Maori. The results have implications for the provision of medical services to Maori people.

A family study of blood pressure in Polynesians.

The family aggregation of blood pressure was studied in Tokelau Island children aged 5-14 years and their parents resident on their home islands in 1971. Five hundred and two (97 per cent) of the children had a recorded blood pressure and they formed 210 sibling groups. The sibship similarity of blood pressure z scores adjusted for year of age and sex was examined by analysis of variance between and within sibships in the 133 sibships with more than one member. For both systolic and diastolic pressure a statistically significant sibship similarity exists which is independent of family size, level of pressure, and the sibship similarity of Quetelet Index. The correlation coefficient of the z score of one index child chosen at random and the remaining siblings is 0-14 (n = 282, p = 0-017). Of the parental variables studied the mother's systolic pressure is the best, and only, predictor of the child's systolic z score. These results suggest that in the Tokelau islanders a family similarity of blood pressure is established relatively early in life.

Varicose veins in the South Pacific.

The prevalence of varicose veins has been studied in several population-based samples in the South Pacific. There is a striking gradient in the age-standardized prevalence rates (0 x 8 per cent to 43 x 7 per cent) with atoll dwellers having the lowest rates, Rarotongans intermediate rates, and New Zealand Maoris and Pakehas the highest rates. The relationship between varicose veins and age, sex, height, weight, body mass and parity is examined and it is concluded that none of these factors are responsible for the observed gradient. The consumption of refined carbohydrates follows the same gradient and the possible aetiological role of this factor is discussed.

Asthma prevalence and deprivation: a small area analysis.

STUDY OBJECTIVE: To investigate the relation between the prevalence of asthma symptoms in adults and deprivation in the area of residence. DESIGN: Two complementary surveys carried out between 1991-1993 yielding adult asthma symptom prevalence throughout New Zealand. Deprivation is measured by the NZDep91 index of deprivation for small areas. SETTING: New Zealand. PARTICIPANTS: A random sample of 25,042 adults aged 20-50 years. MAIN RESULTS: After controlling for possible confounding by age, gender, and ethnicity, the 12 month period prevalence rates of asthma in this representative sample of New Zealand adults are significantly higher in the three most deprived area categories than in the least deprived (tenth) category. The prevalence ratio for the most deprived category compared with the least deprived category is 1.29 with 95% confidence intervals (CI) 1.14, 1.47. There is a linear increase in asthma prevalence with increasing area deprivation (chi 2(1) = 32.20, p < 0.001). Independently, the rates are also 1.41 (95% CI 1.29, 1.54) times higher among Maori and 1.29 (95% CI 1.10, 1.52) times higher among the Pacific Island group than among the remaining, mostly European, respondents. CONCLUSIONS: The relation between asthma in adults and area deprivation is unlikely to be attributable to study biases or confounding. Further work should examine the possible role of modifiable deprivation factors in this relation.

Social deprivation and the public health risks of community drinking water supplies in New Zealand.

STUDY OBJECTIVE: Quantitative evidence linking environmental exposures and social status at sub-national scales is surprisingly limited. This study investigated the public health risks associated with community water supplies in relation to social status in New Zealand. DESIGN: An ecological study using a Geographic Information System (GIS) to compare the grade of community water supplies with an index of social deprivation for small areas. SETTING: New Zealand. PARTICIPANTS: The New Zealand population usually resident in meshblocks (census areas) with a community water supply (70% of the 1996 population of 3.6 million people). MAIN RESULTS: People living in deprived areas are exposed to greater public health risks from community water supplies. In urban areas, the odds of water supplies being high risk were 3.76 times greater for the most deprived decile compared with the least deprived decile (95% CI: 2.95 to 4.78). CONCLUSIONS: It is probable that deprived communities in New Zealand are experiencing a disproportionate burden of adverse health effects as a result of poor water quality.

The Nelson Prescribing Project. A programmed intervention in general practice in New Zealand.

We have defined the effect and acceptability of a locally developed general practice programme for the modification of prescribing. This voluntary programme consisted of prescription analysis and feedback, followed by visits from a pharmacist, a therapeutic bulletin on benzodiazepine prescribing, and use of a locally compiled preferred medicines list. A 3-month prescription sample from 26 general practitioners (GPs) fulfilling a stable practice definition was used to compare prescribing pre-project and mid-project. For 20 out of 26 GPs, prescribing of medicines on the preferred medicines list had increased significantly 8 months after the intervention programme had been introduced. Total prescription numbers and total medicines expenditure decreased by 8.3 and 4.9%, respectively, from 1988 to 1989. The decrease in benzodiazepine prescribing was marked (mean -22.2%, range -50.3 to +4%). The cooperative multimodel approach was highly successful in modifying prescribing in general practice.

Deprivation and sudden infant death syndrome.

This research uses a case-control study to examine the relationship between deprivation of area of residence and incidence of sudden infant death syndrome (SIDS) in New Zealand. Three hundred sixteen cases and 1221 controls were elicited with geocodable addresses. Infants living in the most deprived areas had a 5.9- (95%CI = 2.9, 12.2) fold increased risk of SIDS compared with those infants living in the least deprived areas. After adjusting for individual-level factors there was no remaining area-level effect. Nearly 27% of control infants lived in the two lowest deciles of deprivation, and almost half of SIDS deaths occurred in these areas. Incidence of SIDS is strongly associated with both deprivation of area of residence and individual socioeconomic factors. This indicates the importance of reaching parents in deprived areas, however, given that approximately 50% of SIDS deaths occurred in areas other than the two most deprived, we recommend that SIDS health messages be delivered to the general population.

Does the frame affect the picture? A study into how attitudes to screening for cancer are affected by the way benefits are expressed.

OBJECTIVE: To find out how presenting information about the benefits of screening for cancer in different ways affects an individual's decision to accept or reject screening. METHODS: A telephone survey of the Wellington region, New Zealand was carried out. RESULTS: A response rate of 75.6% was obtained. Respondents were most likely to accept screening when the benefits of screening were presented as a relative risk reduction. They were most likely to reject screening when the benefits were presented as numbers needed to screen to save on life. CONCLUSIONS: An individual's decision about screening for cancer is affected by the way the benefits are framed. Health professionals must choose between framing the benefits of screening in the most positive light, to enhance participation rates, and presenting information in such a way as to reduce framing effects--for example, by expressing the benefits in a variety of forms. Clearly there may be a tension between these approaches; the former is arguably manipulation, and the latter may enhance informed choice, but may also reduce participation rates in screening programmes.

Socioeconomic deprivation and ethnicity are both important for anti-tobacco health promotion.

The aim of the study was to explore the relative importance of socioeconomic deprivation and ethnicity for smoking in New Zealand in order to assist with the design and evaluation of health promotion programs. Smoking data were derived from the 1996 census. Socioeconomic deprivation was measured using the NZDep96 index of socioeconomic deprivation for small areas, which combines nine variables from the 1996 census. There was a strong and consistent relationship between area-level socioeconomic deprivation and the proportion of regular smokers. In all age-groups, at each level of deprivation, Maöri smoked more than the "European and Other" ethnic group. The findings of this study support the view that effective tobacco control activities should address ethnic differences in smoking behavior as well as socioeconomic deprivation, and must operate at the levels of populations, places and environments, as well as individuals.

Anonymous linkage of New Zealand mortality and Census data.

BACKGROUND: The New Zealand Census-Mortality Study (NZCMS) aims to investigate socio-economic mortality gradients in New Zealand, by anonymously linking Census and mortality records. OBJECTIVES: To describe the record linkage method, and to estimate the magnitude of bias in that linkage by demographic and socio-economic factors. METHODS: Anonymous 1991 Census records, and mortality records for decedents aged 0-74 years on Census night and dying in the three-year period 1991-94, were probabilistically linked using Automatch. Bias in the record linkage was determined by comparing the demographic and socio-economic profile of linked mortality records to unlinked mortality records. RESULTS: 31,635 of 41,310 (76.6%) mortality records were linked to one of 3,373,896 Census records. The percentage of mortality records linked to a Census record was lowest for 20-24 year old decedents (49.0%) and highest for 65-69 year old decedents (81.0%). By ethnic group, 63.4%, 57.7%, and 78.6% of Maori, Pacific, and decedents of other ethnic groups, respectively, were linked. Controlling for demographic factors, decedents from the most deprived decile of small areas were 8% less likely to be linked than decedents from the least deprived decile, and male decedents from the lowest occupational class were 6% less likely to be linked than decedents from the highest occupational class. CONCLUSION: The proportion and accuracy of mortality records linked was satisfactorily high. Future estimates of the relative risk of mortality by socio-economic status will be modestly under-estimated by 5-10%.

NZDep91: A New Zealand index of deprivation.

In New Zealand, existing area-based indices of deprivation were inadequate because of lack of theoretical underpinning and use of comparatively large areas resulting in masking of variation within them. There is growing demand for small area based indices of deprivation for the purposes of resource allocation, research, and community advocacy. This paper describes a new Census-based index of deprivation based on the smallest possible geographical areas using existing Census boundaries. The index uses deprivation variables selected according to established theory, and derived from the 1991 New Zealand Census. Ten age and gender standardised variables were combined using principal components analysis. Each variable is a standardised proportion of people in a small area with a lack of a defined material or social resource. Age/gender standardisation is important to avoid confounding and to improve the performance of indices in resource allocation formulae. The index correlates highly with mortality, hospital discharges, lung cancer registrations and childhood immunisation status.

Daily mortality in relation to weather and air pollution in Christchurch, New Zealand.

OBJECTIVE: To investigate the relationship between the daily number of deaths, weather and ambient air pollution. METHOD: An ecological study. We assembled daily data for the city of Christchurch, New Zealand (population 300,000) from June 1988 to December 1993. We used Poisson regression models, controlling for season using a parametric method. RESULTS: Above the third quartile (20.5 degrees C) of maximum temperature, an increase of 1 degree C was associated with a 1% (95% CI: 0.4 to 2.1%) increase in all-cause mortality and a 3% (0.1 to 6.0%) increase in respiratory mortality. An increase in PM10 of 10 micrograms/m3 was associated (after a lag of one day) with a 1% (0.5 to 2.2%) increase in all-cause mortality and a 4% (1.5 to 5.9%) increase in respiratory mortality. We found no evidence of interaction between the effects of temperature and particulate air pollution. CONCLUSIONS: High temperatures and particulate air pollution are independently associated with increased daily mortality in Christchurch. The fact that these results are consistent with those of similar studies in other countries strengthens the argument that the associations are likely to be causal. IMPLICATIONS: These findings contribute to evidence of health consequences of fuel combustion, both in the short term (from local air pollution) and in the long term (from the global climatic effects of increased atmospheric CO2).