Structural modelling of wellbeing for Indigenous Australians: importance of mental health

BACKGROUND

Australia provides health care services for Indigenous peoples as part of its effort to enhance Indigenous peoples' wellbeing. However, biomedical frameworks shape Australia's health care system, often without reference to Indigenous wellbeing priorities. Under Indigenous leadership the Interplay research project explored wellbeing for Indigenous Australians in remote regions, through defining and quantifying Indigenous people's values and priorities. This article aimed to quantify relationships between health care access, mental and physical health, and wellbeing to guide services to enhance wellbeing for Indigenous Australians in remote regions.

METHODS

Indigenous and non-Indigenous researchers worked with Indigenous people in remote Australia to create a framework of wellbeing priorities. Indigenous community priorities were community, culture and empowerment; these interplay with government priorities for Indigenous development of health, education and employment. The wellbeing framework was further explored in four Indigenous communities through a survey which measured aspects of the wellbeing priorities. Indigenous community researchers administered the survey in their home communities to 841 Indigenous people aged 15 to 34 years from June 2014. From the survey items, exploratory factor analysis was used to develop constructs for mental and physical health, barriers to health care access and wellbeing. Relationships between these constructs were quantified through structural equation modelling.

RESULTS

Participants reported high levels of health and physical health (mean scores (3.17/4 [SD 0.96]; and 3.76/4 [SD 0.73]) and wellbeing 8.07/10 [SD 1.94]. Transport and costs comprised the construct for barriers to health care access (mean access score 0.89/1 [SD 0.28]). Structural equation modelling showed that mental health, but not physical health was associated with wellbeing (β = 0.25, P < 0.001; β = - 0.038, P = 0.3). Health care access had an indirect positive relationship with wellbeing through mental health (β = 0.047, P = 0.007). Relationships differed significantly for participants in remote compared with those in very remote communities.

CONCLUSIONS

Greater attention to mental health and recognition of the role of services outside the health care sector may have positive impacts on wellbeing for Indigenous people in remote/ very remote Australia. Aggregation of remote and very remote populations may obscure important differences between Indigenous communities.

Australian Indigenous Land Management, Ecological Knowledge and Languages for Conservation

Many Indigenous Australians hold cultural, ecological and language knowledge, but common representations of Indigenous Australians focus on social disadvantage and poor comparisons with other Australians in education, employment and health. Indigenous Land Management works with Indigenous people's cultural, ecological and language expertise, employing Indigenous people in activities contributing to biodiversity conservation. The Interplay research surveyed 841 Indigenous people in remote communities. Those employed in land management reported greater participation in cultural activities, language knowledge, and belief that their land was looked after. These related assets provide an opportunity for policy approaches based on Indigenous people's strengths and contribution to Australia.

Indigenous land management as primary health care: qualitative analysis from the Interplay research project in remote Australia

BACKGROUND

For Indigenous Australians, health transcends the absence of disease, and includes the health and wellbeing of their community and Country: their whole physical, cultural and spiritual environment. Stronger relationships with Country and greater involvement in cultural practices enhance the wellbeing of Indigenous Australians, and those in more remote regions have greater access to their Country and higher levels of wellbeing. However this does not translate into improvements in clinical indicators, and Indigenous Australians in more remote regions suffer higher levels of morbidity and mortality than Indigenous people in non-remote areas, and other Australians. The Interplay research project aimed to explore how Indigenous Australians in remote regions experience high levels of wellbeing despite poor health statistics, and how services could more effectively enhance both health and wellbeing.

METHODS

Indigenous Australians in remote regions, together with researchers and government representatives developed a wellbeing framework, comprising government and community priorities: education, employment and health, and community, culture and empowerment respectively. To explore these priorities Indigenous community researchers recruited participants from diverse Indigenous organizations, including Indigenous land management, art, business development, education, employment, health and municipal services. Fourteen focus groups and seven interviews, involving 75 Indigenous and ten non-Indigenous service providers and users were conducted. These were recorded, transcribed and analyzed, using thematic analysis, based on the wellbeing framework.

RESULTS

Research participants highlighted Indigenous land management as a source of wellbeing, through strengthened identity and empowerment, access to traditional food sources, enjoyable physical activity, and escape from communities where high levels of alcohol are consumed. Participants described how collaboration and partnerships between services, and recognition of Indigenous languages could enhance wellbeing, while competition between services undermines wellbeing. Indigenous land management programs work across different sectors and promote collaboration between services, serving as a source of comprehensive primary health care.

CONCLUSIONS

Developing primary health care to reflect distinctive health needs of Indigenous Australians will enhance their health and wellbeing, which includes their communities and Country. Indigenous land management consolidates aspects of comprehensive primary health care, providing both clinical benefits and wellbeing, and can provide a focus for service collaboration.

Injury prevention through employment as a priority for wellbeing among Aboriginal people in remote Australia

ISSUE ADDRESSED

Injuries lead to more hospitalisations and lost years of healthy life for Aboriginal people than any other cause. However, they are often overlooked in discussion of relieving Aboriginal disadvantage.

METHODS

Four Aboriginal communities with diverse geography, culture and service arrangements participated in the Interplay Wellbeing project. In each community, Aboriginal researchers conducted focus groups and interviews arranged through Aboriginal organisations to explore wellbeing. A total of 84 participants contributed to 14 focus groups and eight interviews, which were recorded, transcribed and coded. This article reports on injury and possibilities for prevention, unanticipated themes raised in discussions of wellbeing.

RESULTS

Interpersonal violence, injury and imprisonment emerged as themes that were linked with employment and wellbeing. Employment in Aboriginal ranger programs provides meaningful activity, which strengthens people's identity and cultural integrity. This can avert interpersonal violence through empowering women and reducing alcohol access and consumption.

CONCLUSION

Ranger programs may provide a much-needed opportunity to control escalating rates of injury for Aboriginal people in remote communities. SO WHAT?: The manifold benefits of Aboriginal ranger programs include reducing violence and its injury and criminal justice consequences.

Interplay wellbeing framework: a collaborative methodology 'bringing together stories and numbers' to quantify Aboriginal cultural values in remote Australia

Background

Wellbeing has been difficult to understand, measure and strengthen for Aboriginal people in remote Australia. Part of the challenge has been genuinely involving community members and incorporating their values and priorities into assessment and policy. Taking a ‘shared space’ collaborative approach between remote Aboriginal communities, governments and scientists, we merged Aboriginal knowledge with western science – by bringing together stories and numbers. This research aims to statistically validate the holistic Interplay Wellbeing Framework and Survey that bring together Aboriginal-identified priorities of culture, empowerment and community with government priorities including education, employment and health.

Method

Quantitative survey data were collected from a cohort of 842 Aboriginal people aged 15-34 years, recruited from four different Aboriginal communities in remote Australia. Aboriginal community researchers designed and administered the survey.

Results

Structural equation modeling showed good fit statistics (χ/df = 2.69, CFI = 0.95 and RMSEA = 0.045) confirming the holistic nature of the Interplay Wellbeing Framework. The strongest direct impacts on wellbeing were ‘social and emotional wellbeing’ (r = 0.23; p < 0.001), ‘English literacy and numeracy’ (r = 0.15; p < 0.001), ‘Aboriginal literacy’ (r = 0.14; p < 0.001), ‘substances’ (lack thereof; r = 0.13; p = 0.003), ‘work’ (r = 0.12; p = 0.02) and ‘community’ (r = 0.08; p = 0.05). Correlation analyses suggested cultural factors have indirect impacts on wellbeing, such as through Aboriginal literacy. All cultural variables correlated highly with each other, and with empowerment and community. Empowerment also correlated highly with all education and work variables. ‘Substances’ (lack thereof) was linked with positive outcomes across culture, education and work. Specific interrelationships will be explored in detail separately.

Conclusion

The Interplay Wellbeing Framework and Survey were statistically validated as a collaborative approach to assessing wellbeing that is inclusive of other cultural worldviews, values and practices. New community-derived social and cultural indicators were established, contributing valuable insight to psychometric assessment across cultures. These analyses confirm that culture, empowerment and community play key roles in the interplay with education, employment and health, as part of a holistic and quantifiable system of wellbeing. This research supports the holistic concept of wellbeing confirming that everything is interrelated and needs to be considered at the ‘whole of system’ level in policy approaches.

Adolescent inhalant abuse leads to other drug use and impaired growth; implications for diagnosis

OBJECTIVE

Abuse of inhalants containing the volatile solvent toluene is a significant public health issue, especially for adolescent and Indigenous communities. Adolescent inhalant abuse can lead to chronic health issues and may initiate a trajectory towards further drug use. Identification of at-risk individuals is difficult and diagnostic tools are limited primarily to measurement of serum toluene. Our objective was to identify the effects of adolescent inhalant abuse on subsequent drug use and growth parameters, and to test the predictive power of growth parameters as a diagnostic measure for inhalant abuse.

METHODS

We retrospectively analysed drug use and growth data from 118 Indigenous males; 86 chronically sniffed petrol as adolescents.

RESULTS

Petrol sniffing was the earliest drug used (mean 13 years) and increased the likelihood and earlier use of other drugs. Petrol sniffing significantly impaired height and weight and was associated with meeting 'failure to thrive' criteria; growth diagnostically out-performed serum toluene.

CONCLUSIONS

Adolescent inhalant abuse increases the risk for subsequent and earlier drug use. It also impairs growth such that individuals meet 'failure to thrive' criteria, representing an improved diagnostic model for inhalant abuse. Implications for Public Health: Improved diagnosis of adolescent inhalant abuse may lead to earlier detection and enhanced health outcomes.

A prospective study of neurocognitive changes 15 years after chronic inhalant abuse

AIMS

In a previous study, neurological and cognitive deficits reflecting central nervous system (CNS) disruption from chronic inhalant abuse showed substantial recovery after 2 years' abstinence. Functional recovery was progressive, with recovery rates dependent on the degree of impairment prior to abstinence, and severity and duration of initial abuse. Persistent deficits occurred in those with previous 'lead encephalopathy' from leaded petrol abuse. The current study examined recovery in the same cohort 15 years after baseline.

DESIGN

Prospective cohort design.

SETTING

Two remote Aboriginal communities in Arnhem Land, Australia.

PARTICIPANTS

Using baseline group classifications, 27 healthy controls, 60 ex-chronic inhalant abusers and an additional 17 with previous lead encephalopathy were assessed.

MEASUREMENTS

Standard neurological, ocular-motor and cognitive functions and blood lead levels.

FINDINGS

Chronic (non-encephalopathic) inhalant abusers showed elevated blood lead levels and abnormal scores on most tasks at baseline. At 2 years' abstinence, blood lead was reduced but remained elevated and most scores had normalized. By 15 years, blood lead and all performance scores were equivalent to healthy controls for this group (P > 0.05). The encephalopathic group was more severely impaired on all scores at baseline and showed little improvement, if any, across all tests after both 2 and 15 years' abstinence. Blood lead for this group declined, and was not significantly different to controls after 15 years.

CONCLUSIONS

Some inhalant abusers experience severe and persistent neurological deficits, suggesting irrecoverable damage attributable to lead encephalopathy. In the absence of this encephalopathy long-term abstinence from inhalants may allow recovery of normal brain function.

Cognitive recovery during and after treatment for volatile solvent abuse

BACKGROUND

Cognitive impairment reflecting CNS disruption in chronic solvent abusers can resolve within two years of abstinence. However, the specific time course for recovery has yet to be determined empirically. This study monitored cognition among solvent (i.e., gasoline) abusers throughout 8 weeks of residential treatment. It also investigated the extent to which solvent-related cognitive impairments persisted following discharge.

METHODS

Non-drug using healthy controls (n=33) and solvent abusers (n=29) who had inhaled gasoline, regularly or episodically, for an average of 4.3 years (SD=2.7) were assessed. Using linear mixed model analyses, solvent abusers were compared to healthy controls throughout treatment at baseline, two weeks, four weeks and six weeks, on visual motor, attention, learning, memory, and executive function tasks. Ten users who maintained abstinence were reassessed an average of 12 months later (SD=2.8) and were compared to healthy controls (n=12) retested at the same time interval using ANCOVA while controlling for age and baseline performance.

RESULTS

At baseline, solvent abusers showed cognitive deficits on visual motor, learning and memory, paired associate learning, and executive functions. Paired associate learning performance improved within 6 weeks of abstinence, however, impairments in visual motor speed, learning and memory, and executive function persisted throughout and in some cases beyond treatment.

CONCLUSIONS

Cognitive deficits exist for solvent abusers upon treatment entry. Some impairments resolve within weeks of abstinence, while memory and executive function improves gradually over months to years of abstinence, and might never fully recover.

Similar profile of cognitive impairment and recovery for Aboriginal Australians in treatment for episodic or chronic alcohol use

AIMS

The cognitive impairment and recovery associated with chronic alcohol abuse and subsequent abstinence is well understood. However, the recovery profile following heavy episodic or 'binge' use, which is common among some Australian Aboriginal users, has not been investigated thoroughly and no empirical studies have examined chronic use in this population. The aim of this study was to identify and compare cognitive impairment and recovery associated with chronic and episodic alcohol use among Aboriginal Australians.

DESIGN

Longitudinal case-control design.

SETTING

Residential alcohol treatment programmes in northern Australia.

PARTICIPANTS

Forty chronic alcohol users, 24 episodic users and 41 healthy controls [mean age = 34.24; standard deviation (SD) = 9.73].

MEASUREMENTS

Cognitive assessments of visual motor, attention, memory, learning and executive functions at baseline (start of treatment), then 4 weeks and 8 weeks later. Reassessment of 31% of participants an average of 11 months later (SD = 4.4) comparing those who remained abstinent (n = 5), those who relapsed (n = 11) and healthy controls (n = 19).

FINDINGS

At baseline, chronic and episodic alcohol users showed impaired visual motor, learning, memory and executive functions. With the exception of visual motor impairment, all deficits had improved to normal levels within 4 weeks. Visual motor deficits had normalized within 11 months. Performances did not differ at any time between chronic and episodic alcohol groups.

CONCLUSIONS

In Aboriginal Australians, episodic drinking is associated with similar patterns of impairment and recovery as chronic alcohol use. Most cognitive deficits appear to recover within the first month of abstinence, while persisting visual motor problems recover within 1 year.

Detecting psychological symptoms related to substance use among Indigenous Australians

INTRODUCTION AND AIMS

Substance misuse and psychological comorbidities can be common and may impact negatively on treatment outcomes. However, without appropriate tools, detecting psychological symptoms for Indigenous people can be difficult. This study assessed the appropriateness of an eight-item screening tool (based on Strong Souls) for measuring any relationships between substance use and psychiatric symptoms for Indigenous Australians.

DESIGN AND METHODS

Indigenous Australians attending secondary or tertiary education institutions or substance use rehabilitation facilities in the Northern Territory (n = 407; mean age = 27.82) were assessed for depressive, anxiety and psychotic symptoms. The group represented 45 language groups from 95 urban and remote communities. English comprehension was measured on a scale from 0 (no understanding) to 10 (excellent understanding; M = 7.99, SD = 2.31). Ordinal regression analyses examined any associations between demographic and substance use factors and psychological symptoms.

RESULTS

Compared with non-users, current cannabis users were significantly more likely [odds ratios (ORs) = 2.2-4.4] to experience depressive or anxiety symptoms. Frequent cannabis users experienced more symptoms than occasional users. Prior-inhalant users were more likely to feel lonely (OR = 2.18) compared with non-inhalant users. Frequent alcohol users were less likely (OR = 0.44) to feel sad than non-users. These results are interpreted with respect to previous research and methodological limitations.

DISCUSSION AND CONCLUSIONS

Symptoms of depression or anxiety may be common for individuals seeking treatment for substance misuse and with minor improvement, these eight-items may provide a useful screen for psychological symptoms in Indigenous Australians.

The impact of overnight consolidation upon memory for emotional and neutral encoding contexts

Sleep plays a role in the consolidation of declarative memories. Although this influence has attracted much attention at the level of behavioural performance, few reports have searched for neural correlates. Here, we studied the impact of sleep upon memory for the context in which stimuli were learned at both behavioural and neural levels. Participants retrieved the association between a presented foreground object and its encoding context following a 12-h retention interval including either wake only or wake plus a night of sleep. Since sleep has been shown to selectively enhance some forms of emotional memory, we examined both neutral and emotionally valenced contexts. Behaviourally, less forgetting was observed across retention intervals containing sleep than retention intervals containing only wakefulness, and this benefit was accompanied by stronger responses in hippocampus and superior parietal cortex. This sleep-related reduction in forgetting did not differ between neutral and negative contexts, but there was a clear interaction between sleep and context valence at the functional level, with left amygdala, right parahippocampus, and other components of the episodic memory system all responding more strongly during correct memory for emotional contexts post-sleep. Connectivity between right parahippocampus and bilateral amygdala/periamygdala was also enhanced during correct post-sleep attribution of emotional contexts. Because there was no interaction between sleep and valence in terms of context memory performance these functional results may be associated with memory for details about the emotional encoding context rather than for the link between that context and the foreground object. Overall, our data show that while context memory decays less across sleep than across an equivalent period of wake, the sleep-related protection of such associations is not influenced by context emotionality in the same way as direct recollection of emotional information.

Detecting psychological symptoms related to substance use among Indigenous Australians

INTRODUCTION AND AIMS

Substance misuse and psychological comorbidities can be common and may impact negatively on treatment outcomes. However, without appropriate tools, detecting psychological symptoms for Indigenous people can be difficult. This study assessed the appropriateness of an eight-item screening tool (based on Strong Souls) for measuring any relationships between substance use and psychiatric symptoms for Indigenous Australians.

DESIGN AND METHODS

Indigenous Australians attending secondary or tertiary education institutions or substance use rehabilitation facilities in the Northern Territory (n = 407; mean age = 27.82) were assessed for depressive, anxiety and psychotic symptoms. The group represented 45 language groups from 95 urban and remote communities. English comprehension was measured on a scale from 0 (no understanding) to 10 (excellent understanding; M = 7.99, SD = 2.31). Ordinal regression analyses examined any associations between demographic and substance use factors and psychological symptoms.

RESULTS

Compared with non-users, current cannabis users were significantly more likely [odds ratios (ORs) = 2.2-4.4] to experience depressive or anxiety symptoms. Frequent cannabis users experienced more symptoms than occasional users. Prior-inhalant users were more likely to feel lonely (OR = 2.18) compared with non-inhalant users. Frequent alcohol users were less likely (OR = 0.44) to feel sad than non-users. These results are interpreted with respect to previous research and methodological limitations.

DISCUSSION AND CONCLUSIONS

Symptoms of depression or anxiety may be common for individuals seeking treatment for substance misuse and with minor improvement, these eight-items may provide a useful screen for psychological symptoms in Indigenous Australians.

Recovery from central nervous system changes following volatile substance misuse

This review examines cognitive, neurological, and neuroanatomical recovery associated with abstinence from volatile substance misuse (VSM). Articles describing functional or structural brain changes longitudinally or cross-sectional reports comparing current and abstinent users were identified and reviewed. A significant lack of empirical studies investigating central nervous system recovery following VSM was noted. The few case reports and group studies identified indicated that cognitive and neurological impairments appear to follow a progression of decline and progression of recovery model, with the severity of impairment related to the duration and severity of misuse, blood lead levels among leaded petrol misusers, and the duration of abstinence for recovery. By contrast, severe neurological impairment known as lead encephalopathy from sniffing leaded petrol occurred as more catastrophic or abrupt damage to cerebellar processes that may never fully recover. Neuroanatomical damage may not recover even with prolonged abstinence.

The mysterious practice of petrol sniffing in isolated indigenous groups

The practice of petrol sniffing is a unique and poorly understood phenomenon that is associated with substantial morbidity, mortality and social devastation in affected remote Indigenous communities. For these groups and for the wider community, much mystery has surrounded the practice and its effects. Here we introduce the epidemiology of petrol sniffing among Indigenous groups internationally, review its impact on the brain, behaviour and social functions and summarise related interventions.

Strong Souls: development and validation of a culturally appropriate tool for assessment of social and emotional well-being in Indigenous youth

OBJECTIVE

The aim of the present study was to develop and validate an appropriate tool to assess the social and emotional well-being (SEWB) of Indigenous adolescents participating in the longitudinal Aboriginal Birth Cohort (ABC) Study.

METHOD

A range of tools was assessed as to the suitability of each for use in the ABC Study. Two existing tools and a newly developed one called 'Strong Souls' were piloted in a representative group (n = 67). Strong Souls was selected as the most appropriate for use in the ABC Study, and was completed by 361 participants. Exploratory factor analysis was used to explore construct validity. Cronbach alpha was used to assess the reliability of the latent constructs and the tool overall.

RESULTS

Factor analysis produced a 25-item, four-factor model accounting for 34.5% of the variance. This model demonstrated sound construct validity and reliability. Factor structure was consistent with the epidemiological literature, identifying constructs of anxiety, resilience, depression and suicide risk. While these align with observations in mainstream populations, different relationships between distinct factors, and differences in symptomatology were found in this population. For example, two key findings were: feelings of sadness and low mood were linked with anxiety and not depression; and the expression of anger was verified as a unique symptom of depression for Indigenous people.

CONCLUSIONS

Strong Souls demonstrated validity, reliability and cultural appropriateness as a tool for screening for SEWB among Indigenous young people in the Northern Territory.

Psychological and cognitive assessment of Indigenous Australians

OBJECTIVE

The aim of the present review was to evaluate the psychological and cognitive assessments that have been considered suitable for Indigenous Australians. This will provide a basis from which future developments can occur, leading to improved mental health services for Indigenous Australians.

METHOD

Literature searches of key health science databases were conducted using the following search terms in various combinations: Indigenous, Aboriginal, cognitive, assessment, mental health, social emotional well-being, psychological, Australian. Psychological, mental health or social and emotional well-being assessments as well as cognitive assessments that have been utilized and found suitable in Indigenous Australian populations were reviewed.

RESULTS

A limited number of assessments were found and discussed and these varied in their applications.

CONCLUSIONS

Further research and development is necessary to establish a national approach to assessing or screening mental health and cognitive function among Indigenous Australians. This is an important and necessary step to improve mental health and related services for Indigenous Australians.

The importance and challenges of assessing cognition in Indigenous Australians

OBJECTIVES

The aim of this paper was to investigate the importance and challenges involved in conducting serial cognitive assessments among healthy Indigenous adolescents.

METHOD

Cognitive assessments were conducted at fortnightly intervals for 2 months and again at 6 and 12 months among a group of Indigenous students from a boarding school in the Northern Territory. These students were to be the healthy control group in a long-term study of substance abuse. Recruitment and attrition rates were reviewed and related challenges for assessing participants were identified.

RESULTS

From the recruited sample (n=49), 18% reported heavy or frequent use of alcohol, cannabis or petrol. Males were more likely to have used these substances compared to females. Attrition increased as the follow-up interval increased with 49 recruits reducing to 32 in the first 2 months and only 15 and 13 of the initial group remaining for the 6 and 12 month follow-ups respectively.

CONCLUSIONS

Main challenges included (i) appropriateness of tests and assessment processes, (ii) high rates of substance abuse and other illness in the control group and (iii) high attrition rates. The importance of assessing cognition appropriately is highlighted by a lack of information regarding mental health issues in Indigenous populations.

Differences in motor imagery between children with developmental coordination disorder with and without the combined type of ADHD

It has been proposed, and questioned, whether motor impairments in attention-deficit-hyperactivity disorder, combined type (ADHD-C) alone, developmental coordination disorder (DCD) alone, and ADHD-C and comorbid DCD (ADHD-C/DCD) may arise from disruption to a common set of cognitive functions and their related neural substrate. This study examined movement durations for real and imagined movements in a visually guided pointing task in 58 prepubertal children aged 8 to 12 years old with ADHD-C alone (n=14), ADHD-C/DCD (n=14), DCD alone (n=15), and an age-, sex-, and Full-scale IQ-matched healthy comparison group (n=15). There were 10 males and 4 or 5 females in each group. The DCD alone group demonstrated an inability to generate imagined movements that was not present in the ADHD-C group, with or without comorbid DCD, or healthy comparison participants. These findings add to the emerging literature characterizing intended and actual motor impairments associated with DCD alone.

Cognitive impairment in Aboriginal people with heavy episodic patterns of alcohol use

BACKGROUND

With chronic alcohol abuse, cognitive studies suggest that progressive cognitive decline may precede more serious and irreversible neurological syndromes. The early detection of cognitive impairment may therefore aid in the prevention of permanent brain damage. Despite the devastating consequences of alcohol abuse among Aboriginal Australians, the effects on brain function have never been studied in this population and a lack of appropriate assessment tools has prevented the development of such research.

AIMS

To determine the impact of long-term and heavy episodic alcohol use on cognitive function in Aboriginal people.

DESIGN

Cross-sectional comparing heavy episodic alcohol users with non-alcohol users.

SETTING

Two remote Aboriginal communities in north-east Arnhem Land, northern Australia.

SUBJECTS

The control group consisted of 24 non-drinkers (15 males, nine female) and the heavy episodic group consisted of 20 people (19 males, one female) who had been drinking alcohol in a heavy episodic style (median 14 drinks per occasion) for a mean of 8.9 years (SD = 5.0).

MEASUREMENTS

Interview to obtain demographic information, substance abuse history and symptoms of mental health and wellbeing, together with a computerized cognitive assessment battery (CogState Ltd).

FINDINGS

Compared with non-drinkers, heavy episodic drinkers showed reduced psychomotor speed (P = 0.04) and reduced accuracy when performing tasks of attention (P = 0.045), working memory (P = 0.04), implicit memory (P = 0.03) and associate learning and memory (P = 0.001).

CONCLUSIONS

Specific cognitive abnormalities that suggest frontostriatal abnormalities and have been observed in association with chronic alcoholism in other populations were observed among Aboriginal Australians who were heavy episodic alcoholic users.

Changes in cannabis use and its consequences over 3 years in a remote indigenous population in northern Australia

BACKGROUND

Few studies describe cannabis use in indigenous populations, and no longitudinal studies are available in Australia. We conducted 3-year follow-up interviews and assessments in Aboriginal communities in Arnhem Land (Northern Territory, NT).

METHODS

A randomly selected sample (n = 161; 80 males, 81 females aged 13-36 years) was assessed in October 2001 and then reassessed in September 2004. An opportunistically recruited sample (n = 104; 53 males, 51 females aged 13-36 years) was also interviewed in 2001 and followed-up in 2004. Cannabis and other substance use were determined by combining proxy assessments by local Aboriginal health workers, medical records and data from interviews. Changes in cannabis use and symptoms of misuse were assessed using McNemar's test for paired proportions and the Wilcoxon signed rank test. Logistic regression assessed associations between clinical presentations and cannabis use at both time-points.

RESULTS

Those who used cannabis at both baseline and follow-up were at greater risk than those who never used it to have suffered: auditory hallucinations; suicidal ideation; and imprisonment. In the randomly selected cohort there were fewer cannabis users at follow-up than at baseline (P = 0.003). The reduction was evident in females generally (P = 0.008) and older males (aged = 16 at baseline) (P = 0.007). In those interviewed at both baseline and follow-up we measured no statistically significant reduction in frequency and levels of use, although fewer cannabis users reported symptoms of misuse such as: fragmented thought processes; memory disruption; difficulties controlling use; and auditory and visual hallucinations.

CONCLUSIONS

Modest reductions in cannabis use and its consequences in this population were demonstrated. These may be the result of enhanced supply control and broader socio-political changes.

Adverse mental health effects of cannabis use in two indigenous communities in Arnhem Land, Northern Territory, Australia: exploratory study

OBJECTIVE

We investigated adverse mental health effects and their associations with levels of cannabis use among indigenous Australian cannabis users in remote communities in the Northern Territory.

METHOD

Local indigenous health workers and key informants assisted in developing 28 criteria describing mental health symptoms. Five symptom clusters were identified using cluster analysis of data compiled from interviews with 103 cannabis users. Agreement was assessed (method comparison approach, kappa-statistic) with a clinician's classification of the 28 criteria into five groups labelled: 'anxiety', 'dependency', 'mood', 'vegetative' and 'psychosis'. Participants were described as showing 'anxiety', 'dependency' etc., if they reported half or more of the symptoms comprising the cluster. Associations between participants' self-reported cannabis use and each symptom cluster were assessed (logistic regression adjusting for age, sex, other substance use).

RESULTS

Agreement between two classifications of 28 criteria into five groups was 'moderate' (64%, kappa = 0.55, p < 0.001). When five clusters were combined into three, 'anxiety-dependency', 'mood-vegetative' and 'psychosis', agreement rose to 71% (kappa = 0.56, p < 0.001). 'Anxiety-dependency' was positively associated with number of 'cones' usually smoked per week and this remained significant when adjusted for confounders (p = 0.020) and tended to remain significant in those who had never sniffed petrol (p = 0.052). Users of more than five cones per week were more likely to display 'anxiety-dependency' symptoms than those who used one cone per week (OR = 15.8, 1.8-141.2, p = 0.013). A crude association between the 'mood-vegetative' symptom cluster and number of cones usually smoked per week (p = 0.014) also remained statistically significant when adjusted for confounders (p = 0.012) but was modified by interactions with petrol sniffing (p = 0.116) and alcohol use (p = 0.276). There were no associations between cannabis use and 'psychosis'.

CONCLUSIONS

Risks for 'anxiety-dependency' symptoms in cannabis users increased as their level of use increased. Other plausible mental health effects of cannabis in this population of comparatively new users were probably masked by alcohol use and a history of petrol sniffing.

Neurological and cognitive recovery following abstinence from petrol sniffing

Anecdotal observations suggest that neurological impairments associated with petrol (gasoline) sniffing resolve with abstinence, although these effects have not been proven empirically. Severe exposure to leaded petrol may induce a lead encephalopathy that extends beyond any acute intoxication and requires emergency hospital treatment. Previously, in chronic petrol sniffers, we showed neurological, saccadic, and cognitive abnormalities that were more severe in petrol sniffers with a history of hospitalization for lead encephalopathy, and that correlated with blood lead levels and the length of time of sniffing petrol. Ex-petrol sniffers showed a qualitatively similar but quantitatively less severe pattern of impairment. Petrol sniffing was stopped completely in one of the study communities by modifying social, occupational, and recreational opportunities. After 2 years, we obtained biochemical and neurobehavioral (neurological, saccade, and cognitive) data from all available participants of the earlier study including 10 nonsniffers and 29 chronic petrol sniffers, with six of these individuals previously receiving hospital treatment for lead encephalopathy. Here, we report that blood lead was reduced and that neurobehavioral impairments improved, and in many cases normalized completely. The most severe petrol-related neurobehavioral impairment was observed among individuals who had longer histories of abuse and higher blood lead levels, and among petrol sniffers with a history of lead encephalopathy. Those with the greatest extent of neurobehavioral impairment showed the greatest degree of improvement with abstinence, but were less likely to recover completely. This is the first direct evidence that neurological and cognitive impairment from chronic petrol sniffing ameliorates with abstinence and may recover completely.

Emerging patterns of cannabis and other substance use in Aboriginal communities in Arnhem Land, Northern Territory: a study of two communities

A recent rise in cannabis use in Indigenous communities in northern Australia may have compounded existing patterns of other substance use. This paper describes these patterns in Arnhem Land in the 'Top End' of the Northern Territory (NT). Economic impacts of the cannabis trade are also described. In a descriptive cross-sectional study, random samples included 336 people (169 males, 167 females) aged 13 - 36 years. Consensus classification of lifetime and current use of cannabis, alcohol, tobacco, kava, inhalants (petrol) and other drugs was derived based on health workers' proxy assessments. A sample (n = 180, aged 13 - 36) was recruited opportunistically for interview. Lifetime cannabis users among those interviewed (n = 131, 81 males, 50 females) described their current cannabis use, usual quantities purchased and consumed, frequency and duration of cannabis use and other substance use. In the random samples, 69% (63 - 75%) of males and 26% (20 - 31%) of females were lifetime cannabis users (OR = 7.4, 4.5 - 12.1, p < 0.001). The proportion of males currently using cannabis was 67% (60 - 73%) while the proportion of females currently using cannabis was 22% (16 - 27%) (OR = 7.9, 4.8 - 13.1, p < 0.001). Current cannabis users were more likely than non-users to be also using alcohol (OR = 10.4, 4.7 - 23.3, p < 0.001), tobacco (OR = 19.0, 7.9 - 45.8, p < 0.001) and to have sniffed petrol (OR = 9.1, 4.6 - 18.0, p < 0.001) but were less likely to be using kava (OR = 0.4, 0.2 - 0.9, p < 0.001). Among those interviewed, higher tobacco consumption in current users and greater alcohol use in lifetime users was associated with increased cannabis use. Action is required to reduce cannabis use, especially in combination with other substances.

Saccade dysfunction associated with chronic petrol sniffing and lead encephalopathy

BACKGROUND

In chronic petrol sniffers, recent exposure to high levels of leaded petrol may give rise to a lead encephalopathy characterised by tremor, chorea, ataxia, hyperreflexia, convulsive seizures, and death. Neurological abnormalities associated with lead encephalopathy involve the cortex, basal ganglia, cerebellum, and brain stem.

OBJECTIVE

To use saccadic eye movement tasks as an experimental tool to determine which CNS changes are associated with chronic petrol sniffing and which with a history of lead encephalopathy, and to what extent these changes are reversible.

METHODS

Saccade function was assessed in chronic petrol sniffers with a history of lead encephalopathy (encephalopathic sniffers), chronic petrol sniffers who had never suffered lead encephalopathy (chronic sniffers), individuals who had sniffed petrol in the past but had not done so for more than six months (ex-sniffers), and individuals who had never sniffed petrol (non-sniffers).

RESULTS

Chronic sniffers showed increased latency of visually guided saccades and antisaccades and increased antisaccade errors which suggested cortical and basal ganglia dysfunction. These abnormalities returned to normal in ex-sniffers. Encephalopathic sniffers showed the same abnormalities as chronic sniffers but with greater severity and additional saccadic signs including dysmetria, gaze evoked nystagmus, and saccade slowing which usually indicate cerebellar and brain stem dysfunction.

CONCLUSIONS

Chronic petrol abuse is associated with cortical and basal ganglia abnormalities that are at least partially recoverable with abstinence. Additional long term cerebellar and brain stem abnormalities are associated with lead encephalopathy.

Neurological and cognitive impairment associated with leaded gasoline encephalopathy

BACKGROUND

A toxic encephalopathy (or 'lead encephalopathy') may arise from leaded gasoline abuse that is characterised by tremor, hallucinations, nystagmus, ataxia, seizures and death. This syndrome requires emergency and intensive hospital treatment.

METHODS

We compared neurological and cognitive function between chronic gasoline abusers with (n=15) and without (n=15) a history of leaded gasoline encephalopathy, and with controls who had never abused gasoline (n=15).

RESULTS

Both groups of chronic gasoline abusers had abused gasoline for the same length of time and compared to controls, showed equivalently elevated blood lead levels and cognitive abnormalities in the areas of visuo-spatial attention, recognition memory and paired associate learning. However, where gasoline abusers with no history of leaded gasoline encephalopathy showed only mild movement abnormalities, gasoline abusers with a history of leaded gasoline encephalopathy showed severe neurological impairment that manifest as higher rates of gait ataxia, abnormal rapid finger tapping, finger to nose movements, dysdiadochokinesia and heel to knee movements, increased deep tendon reflexes and presence of a palmomental reflex.

CONCLUSIONS

While neurological and cognitive functions are disrupted by chronic gasoline abuse, leaded gasoline encephalopathy is associated with additional and long-lasting damage to cortical and cerebellar functions.

Saccade and cognitive impairment associated with kava intoxication

Kava is an extract from the Piper methysticum Forst. f. plant that has social and spiritual importance in Pacific islands societies. Herbal remedies that contain kava are used for the psychiatric treatment of anxiety and insomnia. Laboratory studies have found only subtle, if any, changes on cognitive or motor functions from the acute effects of consuming small clinical doses of kava products. Intoxication from recreational doses of kava has not been studied. The performance of individuals intoxicated from drinking kava (n=11) was compared with a control group (n=17) using saccade and cognitive tests. On average, intoxicated individuals had consumed 205 g of kava powder each (approximately 150 times clinical doses) in a group session that went for 14.4 h and ended 8 h prior to testing. Intoxicated kava drinkers showed ataxia, tremors, sedation, blepharospasm and elevated liver enzymes (GGT and ALP), together with saccadic dysmetria, saccadic slowing and reduced accuracy performing a visual search task that only became evident as the task complexity increased. Kava intoxication is characterized by specific abnormalities of movement coordination and visual attention but normal performance of complex cognitive functions. Saccade abnormalities suggest disruption of cerebellar and GABAergic functions.

Saccade and cognitive function in chronic kava users

Kava is an extract from the Piper methysticum Forst. f. plant that has been consumed in the Pacific islands for millennia and more recently, among indigenous populations, in northern Australia and throughout the Western world as an herbal medicine. Through alterations on neuronal excitation, kava induces muscle relaxation, anasthesia, and has anxiolytic properties. There have been several isolated reports of psychotic syndromes, severe choreoathetosis and possible seizures following kava use. However, there is no conclusive evidence that kava interferes with normal cognitive processes. We tested a group of current, ex, and nonkava users among an indigenous population in northern Australia, using saccade and cognitive tests that have proven cross-cultural validity and are sensitive to subtle disruptions of the brain arising from substance abuse or neuropsychiatric illness. Despite collecting data from among the heaviest reported kava drinkers in the world, we found no impairment in cognitive or saccade function in individuals who were currently heavy kava users (and had been for up to 18 years), nor was there any impairment in individuals who had been heavy kava users in the past but had abstained for longer than 6 months. Current and ex-kava users showed a higher rate of kava dermopathy, lower body mass index, lowered blood lymphocytes and, in addition, current kava users showed elevated liver enzymes. While there has recently been increasing concern about potentially fatal liver damage attributed to kava use, we have found no evidence of brain dysfunction in heavy and long-term kava users.

The neurobehavioural effects of kava

OBJECTIVE

This review considers the context in which kava is used, together with its underlying psychopharmacological mechanisms, to investigate the neurobehavioural effects associated with kava use.

METHOD

We conducted a systematic search using the computerized databases MEDLINE, OVID and PsychLIT for all articles containing any of the following words: kava, kavain, kawa and Piper methysticum. In the opinion of the authors, all articles from this collection containing data that could inform the neurological and cognitive sequelae of kava use were included for the purpose of this review.

RESULTS

The use of kava occurs among indigenous populations in the South Pacific and in northern Australia, while also being used throughout the western world as a herbal medicine. Animal studies show that kava lactones alter neuronal excitation through direct interactions with voltage-dependent ion channels, giving rise to kava's muscle relaxant, anaesthetic, anxiolytic and anticonvulsive properties. Several isolated cases of psychotic and severe dystonic reactions following kava use suggest that kava also has psychoactive properties, yet there is no conclusive evidence that kava interferes with normal cognitive processes.

CONCLUSIONS

Kava is effective in the treatment of tension and anxiety. There may be risk-factors for severe motor and psychiatric responses to kava use, although these are not well-understood. Given the increasingly widespread use of kava, further investigation is necessary to gain an understanding of its immediate neuropsychiatric effects and long-term cognitive effects.

The neurobehavioural consequences of petrol (gasoline) sniffing

This review will introduce petrol (gasoline) sniffing as a specific form of substance abuse. Petrol sniffing is associated with dysfunctions that range in severity from subtle cognitive impairment to encephalopathy and death, and these are discussed with respect to their specific neurological and cognitive bases. Morbidity and mortality rates will also be presented that suggest severe central nervous system damage occurs as a result of petrol sniffing. The neuropharmacological actions of tetraethyl lead and volatile hydrocarbons, the components within petrol, and their contributions to the effects of sniffing petrol are investigated. Reports of human occupational or recreational exposure to either lead additives or volatile hydrocarbons (i.e. inhalants) have provided evidence of the neurological and cognitive effects that may also occur with petrol sniffing. Petrol sniffing causes a progressive decline of cognitive function that eventually leads to permanent neurological changes.

Contextual abnormalities of saccadic inhibition in children with attention deficit hyperactivity disorder

Abnormalities of executive function are observed consistently in children with attention-deficit hyperactivity disorder (ADHD), and it is hypothesised that these arise because of disruption to a behavioural inhibition system. Executive and inhibitory functions were compared between unmedicated and medicated children with ADHD (combined type), age-matched healthy children and healthy adults. Executive functions were measured using a test of spatial working memory shown previously to be sensitive to ADHD and to stimulant medication. Inhibitory functions were measured using an ocular motor paradigm that required individuals to use task context to control the release of fixation. Context was set according to the probability that a target would appear at either of the two locations. In one block, targets appeared on 80% of trials. In the other block, targets appeared on 20% of trials. The ability to control the release of fixation was inferred from the fixation offset effect (FOE), or the difference in saccade latency when the current fixation is offset 200 ms prior to the onset of the saccade target (gap condition), compared with when there is no offset (overlap condition). Although the healthy children made more errors on the spatial working memory task than the healthy adults, there was no difference between the two groups in their ability to control fixation using context. Both showed a larger FOE when target probability was low. As expected, the unmedicated ADHD group made more errors on the spatial working memory test than the healthy children, although spatial working memory performance was normal in the medicated ADHD group. However, both the unmedicated and medicated ADHD groups were unable to modulate the FOE according to context, and this was due to their inability to voluntarily inhibit saccades when there was a low target probability. These data suggest that the context-based modulation of fixation release is not controlled by the same systems that control executive function. Furthermore, deficits in executive function and inhibitory control appear independent in children with ADHD.

The ability to execute saccades on the basis of efference copy: impairments in double-step saccade performance in children with developmental co-ordination disorder

The double-step saccade task (DSST) was used to test the hypothesis that children with developmental co-ordination disorder (DCD) who experience deficits in motor imagery have difficulty processing the visual spatial consequences of intended movements using efference copy signals. In order to ensure that the second saccade in the DSST was executed in the absence of visual cues and had to be programmed on the basis of extra-retinal information (efference copy), we analysed only those double-step ensembles where latency plus duration of first saccades was greater than 240 ms (total presentation time of the targets). No significant differences between DCD and control children were evident on measures of latency of first saccades, intersaccadic interval and first saccade error. As predicted, children with DCD who have impaired motor imagery demonstrated specific deficits on the DSST where efference copy had been used to program the saccade sequence. More specifically, these children were less accurate in terms of final eye position on second saccades. Our results raise the possibility that abnormalities in the processing of efference copy signals could underlie motor clumsiness in the majority of children with DCD. Furthermore, the origin of this deficit in efference copy probably exists at the level of the parietal lobe.