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To identify common variants contributing to normal variation in two specific domains of cognitive functioning, we conducted a genome-wide association study (GWAS) of executive functioning and information processing speed in non-demented older adults from the CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology) consortium. Neuropsychological testing was available for 5429-32,070 subjects of European ancestry aged 45 years or older, free of dementia and clinical stroke at the time of cognitive testing from 20 cohorts in the discovery phase. We analyzed performance on the Trail Making Test parts A and B, the Letter Digit Substitution Test (LDST), the Digit Symbol Substitution Task (DSST), semantic and phonemic fluency tests, and the Stroop Color and Word Test. Replication was sought in 1311-21860 subjects from 20 independent cohorts. A significant association was observed in the discovery cohorts for the single-nucleotide polymorphism (SNP) rs17518584 (discovery P-value=3.12 × 10(-8)) and in the joint discovery and replication meta-analysis (P-value=3.28 × 10(-9) after adjustment for age, gender and education) in an intron of the gene cell adhesion molecule 2 (CADM2) for performance on the LDST/DSST. Rs17518584 is located about 170 kb upstream of the transcription start site of the major transcript for the CADM2 gene, but is within an intron of a variant transcript that includes an alternative first exon. The variant is associated with expression of CADM2 in the cingulate cortex (P-value=4 × 10(-4)). The protein encoded by CADM2 is involved in glutamate signaling (P-value=7.22 × 10(-15)), gamma-aminobutyric acid (GABA) transport (P-value=1.36 × 10(-11)) and neuron cell-cell adhesion (P-value=1.48 × 10(-13)). Our findings suggest that genetic variation in the CADM2 gene is associated with individual differences in information processing speed.

General cognitive function is substantially heritable across the human life course from adolescence to old age. We investigated the genetic contribution to variation in this important, health- and well-being-related trait in middle-aged and older adults. We conducted a meta-analysis of genome-wide association studies of 31 cohorts (N=53,949) in which the participants had undertaken multiple, diverse cognitive tests. A general cognitive function phenotype was tested for, and created in each cohort by principal component analysis. We report 13 genome-wide significant single-nucleotide polymorphism (SNP) associations in three genomic regions, 6q16.1, 14q12 and 19q13.32 (best SNP and closest gene, respectively: rs10457441, P=3.93 × 10(-9), MIR2113; rs17522122, P=2.55 × 10(-8), AKAP6; rs10119, P=5.67 × 10(-9), APOE/TOMM40). We report one gene-based significant association with the HMGN1 gene located on chromosome 21 (P=1 × 10(-6)). These genes have previously been associated with neuropsychiatric phenotypes. Meta-analysis results are consistent with a polygenic model of inheritance. To estimate SNP-based heritability, the genome-wide complex trait analysis procedure was applied to two large cohorts, the Atherosclerosis Risk in Communities Study (N=6617) and the Health and Retirement Study (N=5976). The proportion of phenotypic variation accounted for by all genotyped common SNPs was 29% (s.e.=5%) and 28% (s.e.=7%), respectively. Using polygenic prediction analysis, ~1.2% of the variance in general cognitive function was predicted in the Generation Scotland cohort (N=5487; P=1.5 × 10(-17)). In hypothesis-driven tests, there was significant association between general cognitive function and four genes previously associated with Alzheimer's disease: TOMM40, APOE, ABCG1 and MEF2C.

Importance: Interventions that substantially slow neurodegeneration are needed to address the growing burden of Alzheimer disease (AD) to societies worldwide. Elevated brain iron observed in AD has been associated with accelerated cognitive decline and may be a tractable drug target., Objective: To investigate whether the brain-permeable iron chelator deferiprone slows cognitive decline in people with AD., Design, Setting, and Participants: This phase 2, double-masked, placebo-controlled randomized clinical trial of 12-month duration was conducted at 9 sites in Australia between August 2, 2018, and April 1, 2023. Patients older than 54 years with amyloid-confirmed mild cognitive impairment or early AD (a Mini-Mental State Examination score of 20 or higher) were screened. Randomization was 2:1 and masked to participants and all study staff., Interventions: Deferiprone 15 mg/kg twice a day or placebo administered orally for 12 months., Main Outcomes and Measures: The primary outcome was a composite cognitive measure assessed at baseline, 6 months, and 12 months using a neuropsychological test battery (NTB) of memory, executive function, and attention tasks. Secondary outcomes included change in brain iron burden measured by quantitative susceptibility mapping (QSM) magnetic resonance imaging (target engagement), brain volume changes (secondary efficacy measure), and adverse events (safety analysis)., Results: Of 167 patients screened for eligibility, 81 were included, with 53 randomly assigned to the deferiprone group (mean [SD] age, 73.0 [8.0] years; 29 male [54.7%]) and 28 to the placebo group (mean [SD] age, 71.6 [7.2] years; 17 male [60.7%]); 54 participants completed the study (7 [25.0%] withdrew from the placebo group and 20 [37.7%] from the deferiprone group). In an intention-to-treat analysis, participants in the deferiprone group showed accelerated cognitive decline on the NTB primary outcome (β for interaction = -0.50; 95% CI, -0.80 to -0.20) compared with placebo (change in NTB composite z score for deferiprone, -0.80 [95% CI, -0.98 to -0.62]; for placebo, -0.30 [95% CI, -0.54 to -0.06]). Secondary analysis revealed that this result was driven by worsening performance on executive function tests. The QSM confirmed that deferiprone decreased iron in the hippocampus compared with placebo (change in hippocampal QSM for deferiprone, -0.36 ppb [95% CI, -0.76 to 0.04 ppb]; for placebo, 0.32 ppb [95% CI, -0.12 to 0.75 ppb]; β for interaction = -0.68 [95% CI, -1.27 to -0.09]). Longitudinal hippocampal volume loss was not affected by deferiprone, but exploratory analysis of other brain regions revealed increased volume loss with deferiprone in frontal areas. The frequency of the adverse effect of neutropenia (4 participants [7.5%] in the deferiprone group) was higher than in similar studies (1.6%-4.4%)., Conclusions: These trial findings show that deferiprone 15 mg/kg twice a day decreased hippocampal QSM and accelerated cognitive decline in patients with amyloid-confirmed early AD, suggesting that lowering iron with deferiprone is detrimental to patients with AD., Trial Registration: ClinicalTrials.gov Identifier: NCT03234686.

Importance: People living with psychosis experience excess premature mortality and are overrepresented in criminal legal systems, but little is known about mortality associated with criminal sanctions or diversion in this population., Objective: To examine associations of different types of recent (past 2 years) criminal sanction, including court diversion, with mortality among people with psychosis., Design, Setting, and Participants: This population-based, retrospective, data-linkage cohort study was conducted using 6 routinely collected administrative data collections from New South Wales, Australia, relating to health, court proceedings, imprisonment, and mortality. Participants (adults aged ≥18 years hospitalized for psychotic disorders) entered observation at the time of discharge from their first psychosis-related hospital admission (or their 18th birthday if aged <18 years) between July 2001 and November 2017 and were followed-up until May 2019. Data were analyzed between February 2023 and April 2024., Exposures: Recent (past 2 years) criminal sanction type, a time-varying variable with 5 categories: no recent criminal sanction, recent mental health court diversion, recent community sanction, current imprisonment, and recent prior imprisonment (ie, recent prison release)., Main Outcomes and Measures: Causes of death were described, and age- and sex-specific mortality rates by recent criminal sanction type were calculated. In those younger than 65 years, Cox regression was used to examine associations of all-cause and external-cause mortality with recent criminal sanction type, adjusting for sociodemographic, health-related, and offense-related confounders., Results: The cohort included 83 071 persons (35 791 female [43.1%]; 21 208 aged 25-34 years [25.5%]; median [IQR] follow-up, 9.5 [4.8-14.2] years), of whom 25 824 (31.1%) received a criminal sanction. There were 11 355 deaths. In those aged younger than 65 years, recent mental health court diversion, community sanctions, and prior imprisonment were associated with increased hazards of all-cause and external-cause mortality compared with no recent sanction, with the largest adjusted hazard ratios (aHRs) observed for recent prior imprisonment (all-cause mortality: aHR, 1.69; 95% CI, 1.50-1.91; external-cause mortality: aHR, 2.64; 95% CI, 2.27-3.06)., Conclusions and Relevance: In this cohort study of people with psychosis, recent criminal sanctions were associated with increased mortality irrespective of sanction type. These findings suggest that future research should develop strategies to improve health and safety in people with psychosis who have criminal legal system contact.

Women who use violence represent one of the fastest growing groups within the Australian prisoner population, including Aboriginal women who are more likely to be incarcerated than non-Aboriginal women for violent crimes. Many incarcerated women report histories of adverse childhood experiences (ACEs) and intimate partner violence. This exploratory study examines baseline data from a sample of 167 women in 3 Western Australia women's prisons enrolled in a gender-specific violent behavior program. It describes their exposure to intimate partner violence, head injury, and childhood adversities. Overall, 94% of women had experienced at least one childhood adversity (median 6), and 94% reported being a victim of physical violence by a current or former intimate partner. Aboriginal women were more likely than non-Aboriginal women to report that a family member was incarcerated as a child ( p  = .001). There was an association between an increased number of ACEs and head injury with a loss of consciousness ( p  = .008). Overall, these results present a harrowing picture of childhood exposure to adversity and violence in adulthood. Successful rehabilitation of women incarcerated for violent crimes should be cognizant of the histories of extreme violence endured by most of these women., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Mental health services are available for young people involved with the criminal justice system. However, they have unmet mental health needs after the expiration of criminal justice supervision., Objective: To determine the incidence rate and identify predictors of psychiatric hospitalisations within 24 months after the expiration of criminal justice supervision among young people involved with the New South Wales (NSW) criminal justice system., Methods: Retrospective data from 1556 individuals aged 14-22 years who participated in four surveys of justice-involved young people in NSW were harmonised and linked to four NSW data collections. We calculated the incidence rates of psychiatric hospitalisations within 24 months postsupervision and identified predictors of these hospitalisations using a competing risks regression analysis., Results: Within 24 months postsupervision, 11.4% had a psychiatric hospitalisation compared with 3.5% during supervision. 20.7% of those admitted had a known history of mental illness and engaged with community-based and outpatient mental health services postsupervision. Predictors of psychiatric hospitalisations were: female sex (adjusted subdistribution HR (asHR) 1.84, 95% CI 1.24 to 2.73); previous incarceration (highest asHR for ≥4 episodes 1.67, 95% CI 1.01 to 2.78); head injury (asHR 1.63, 95% CI 1.20 to 2.21); personality disorder (asHR 3.66, 95% CI 2.06 to 6.48) and alcohol and substance use disorder (asHR 1.89, 95% CI 1.29 to 2.77)., Conclusion: Justice-involved youth have higher rates of psychiatric admissions after criminal justice supervision. Engagement with mental health services postsupervision is important in addressing emerging or persisting mental health needs., Competing Interests: Competing interests: No, there are no competing interests., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. Published by BMJ.)

Background: Olfactory deficits have a diverse etiology and can be detected with simple olfactory tests. Key olfactory pathways are located within the frontal and temporal lobes where they are vulnerable to damage due to head trauma. Orbitofrontal cortex (OFC) integrity is important for olfaction and aspects of behavioral regulation. We measured olfactory identification ability in a sample of impulsive violent offenders to determine its associations with history of traumatic brain injury (TBI) and a range of neuropsychiatric indices, including proxies for cognitive ability, impulsivity and social connectedness., Methods: Male participants were drawn from the ReINVEST study, a randomized controlled trial of sertraline to reduce recidivism in violent impulsive offenders. Criteria for participation in the study included a minimum age of 18 years, a documented history of two or more violent offenses, and a score of 70 or above on the Barratt Impulsiveness Scale (BIS-11). The 16-item "Sniffin sticks" (SS) odor identification test (OI) was administered as were standardized questionnaires regarding previous TBI, additional measures to screen cognition [word reading test of the Wechsler Individuals Achievement Test (WIAT), social connectedness (the Duke Social Support Scale), and a range of other neuropsychiatric conditions or symptoms]. The sample SS scores were compared against published age-specific norms. Univariate and multivariate analyses were performed with SS score (linear regression, within those without hyposmia) or hyposmia (logistic regression) as the outcome., Results: The mean OI scores were lower than population norms and 16% of participants were classified as hyposmic. Univariate analyses showed associations of SS score with age, WIAT score, impulsivity, TBI and TBI severity, social connectedness, childhood sexual abuse, suicidality and current use of heroin. In multivariate analyses, age, TBI severity and WIAT remained as significant independent predictors of SS score (within the normosmic range) or hyposmia (logistic regression)., Conclusion: Olfactory performance was associated with multiple behavioral phenomena in a pattern that would be consistent with this serving as a proxy for orbitofrontal functioning. As such, OI testing may have utility in further studies of offenders. In future, we will examine whether olfactory score predicts recidivism or response to the administration of sertraline, in terms of reducing recidivism., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Challakere Ramaswamy, Butler, Ton, Wilhelm, Mitchell, Knight, Greenberg, Ellis, Gebski and Schofield.)

Background: Traumatic brain injury (TBI) is a major public health problem that may be associated with numerous behavioral problems, including impulsivity, aggression and violence. Rates of self-reported TBI are high within offender populations, but the extent to which TBI is causally implicated in causing illegal behavior is unclear. This study examined the psychological and functional correlates of histories of traumatic brain injury in a sample of impulsive violent offenders., Methods: Study participants, all men, had been recruited to participate in a randomized controlled trial of sertraline to reduce recidivism. Study entry criteria were an age of at least 18 years, a documented history of two or more violent offenses and a score of 70 or above on the Barratt Impulsiveness Scale. An extensive list of standardized questionnaires was administered to obtain information on previous TBI and other neuropsychiatric conditions or symptoms., Results: In the sample of 693 men, 66% were aged between 18 and 35 years old, and 55% gave a history of TBI ("TBI+"). Overall, 55% of study participants reported at least one TBI. High levels of neuropsychiatric symptomatology were reported. In 75% of TBI+ individuals, their most severe TBI (by self-report) was associated with loss of consciousness (LOC) < 30 min. Compared to TBI- (those without history of TBI) participants, TBI+ individuals were more impulsive (Eysenck Impulsivity), irritable, angry, and reported higher levels of assaultive behavior, depressive symptomology, alcohol use disorder, suicidal ideation, suicide attempts, and lower quality of life. Potential "dose effects" of TBI severity and frequency in terms of neuropsychiatric symptomatology were identified., Conclusion: Like other studies of offender populations, single and multiple TBIs were very common. The associations of TBI, TBI severity, and TBI frequency (i.e., TBI "burden") with adverse neuropsychiatric phenomena suggest TBI contributes importantly to offender morbidity but the select nature of the sample and cross-sectional study design constrain the interpretation of these findings., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Challakere Ramaswamy, Butler, Ton, Wilhelm, Mitchell, Knight, Greenberg, Ellis, Allnutt, Jones, Gebski, Carr, Scott and Schofield.)

Background: An association exists between psychosis and criminal offending, which evidence suggests can be reduced by effective mental health care for this vulnerable population. However mental health services often lose contact with people after diagnosis. The association between the first episode of psychosis and criminal offending highlights the need for effective mental health care for this vulnerable population., Aims: To investigate the association between the first diagnosis of psychosis (FDP) in prison or hospital and subsequent mental health service contact following release from prison or discharge from hospital., Materials and Methods: Individuals with a FDP either in prison ( n = 492) or hospital setting ( n = 24,910) between July 2006 and December 2011 in NSW (Australia), were followed post-release or discharge until their first mental health service contact in the community, the occurrence of an offence, death, or completion of the study period at the end of December 2012. Cox regression models were used to examine the predictors for the mental health service contacts following release or discharge., Results: Over 70% of those with a FDP in prison or hospital had a psychosis-related or any community-based mental health service contact following release or discharge between July 2006 and December 2012. Those with a FDP in prison were more likely to have no contact with mental health services than those in hospital with no prior offence record (hazard ratio, HR = 3.14, 95% CI: 2.66-3.72 and adjusted hazard ratio, aHR = 3.05, 95% CI: 2.56-3.63) within a median follow-up time of 25 days for the prison group and 26 days for hospital group. Males, individuals of Aboriginal heritage and individuals diagnosed with substance-related psychoses compared to those with schizophrenia and related psychoses were less likely to have a mental health service contact following release or discharge in both the univariable and multivariable analysis., Conclusion: This study suggests that prior offending or a previous prison episode represents a barrier to mental health service contact in the community for those with a FDP. Effective rehabilitation planning while exiting prison and discharge planning from hospital are essential to the successful reintegration of these individuals with a FDP., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Chowdhury, Wand, Albalawi, Adily, Kariminia, Allnutt, Sara, Dean, Ellis, Greenberg, Schofield and Butler.)

Understanding the genomic basis of memory processes may help in combating neurodegenerative disorders. Hence, we examined the associations of common genetic variants with verbal short-term memory and verbal learning in adults without dementia or stroke (N = 53,637). We identified novel loci in the intronic region of CDH18, and at 13q21 and 3p21.1, as well as an expected signal in the APOE/APOC1/TOMM40 region. These results replicated in an independent sample. Functional and bioinformatic analyses supported many of these loci and further implicated POC1. We showed that polygenic score for verbal learning associated with brain activation in right parieto-occipital region during working memory task. Finally, we showed genetic correlations of these memory traits with several neurocognitive and health outcomes. Our findings suggest a role of several genomic loci in verbal memory processes., (© 2022. The Author(s).)

In Australia, domestic violence reports are mostly based on data from the police, courts, hospitals, and ad hoc surveys. However, gaps exist in reporting information such as victim injuries, mental health status and abuse types. The police record details of domestic violence events as structured information (e.g., gender, postcode, ethnicity), but also in text narratives describing other details such as injuries, substance use, and mental health status. However, the voluminous nature of the narratives has prevented their use for surveillance purposes. We used a validated text mining methodology on 492,393 police-attended domestic violence event narratives from 2005 to 2016 to extract mental health mentions on persons of interest (POIs) (individuals suspected/charged with a domestic violence offense) and victims, abuse types, and victim injuries. A significant increase was observed in events that recorded an injury type (28.3% in 2005 to 35.6% in 2016). The pattern of injury and abuse types differed between male and female victims with male victims more likely to be punched and to experience cuts and bleeding and female victims more likely to be grabbed and pushed and have bruises. The four most common mental illnesses (alcohol abuse, bipolar disorder, depression schizophrenia) were the same in male and female POIs. An increase from 5.0% in 2005 to 24.3% in 2016 was observed in the proportion of events with a reported mental illness with an increase between 2005 and 2016 in depression among female victims. These findings demonstrate that extracting information from police narratives can provide novel insights into domestic violence patterns including confounding factors (e.g., mental illness) and thus enable policy responses to address this significant public health problem., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Karystianis, Adily, Schofield, Wand, Lukmanjaya, Buchan, Nenadic and Butler.)

Introduction: Considerable evidence supports an association between poor impulse control (impulsivity) and violent crime. Furthermore, impulsivity and aggression has been associated with reduced levels of serotonergic activity in the brain. Selective serotonin reuptake inhibitors (SSRIs) are a class of anti-depressants that aim to regulate brain serotonin concentrations. Several small studies in psychiatric populations have administered SSRIs to impulsive--aggressive individuals, resulting in reduced impulsivity, anger, aggression and depression. However, no clinical trial has been undertaken in a criminal justice population. This protocol describes the design and implementation of the first systematic study of the potential benefits of SSRIs in impulsive---violent offenders who are at high risk of reoffending., Methods and Analysis: A randomised, double-blinded, multicentre trial to test the clinical efficacy of an SSRI, sertraline hydrochloride, compared with placebo on recidivism and behavioural measures (including impulsivity, anger, aggression, depression and self-reported offending) over 12 months. 460 participants with histories of violence and screening positive for impulsivity are recruited at several local courts and correctional service offices in New South Wales, Australia., Ethics and Dissemination: Results will be submitted for publication in a peer-reviewed journal. Possible implications of the effectiveness of this pharmacological intervention include economic benefits of reducing prison costs and societal benefits of improving safety. This study has received ethical approval from the University of New South Wales, Aboriginal Health & Medical Research Council, Corrective Services NSW and the NSW Justice Health and Forensic Mental Health Network., Trial Registration Number: ACTRN12613000442707., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Interventions to better manage aggressive behaviour and reduce recidivism are a primary concern for corrective services. Nutritional interventions to correct prisoner behaviour have been largely overlooked in the literature. Emerging evidence suggests that dietary intake influences aggressive behaviours and that nutritional supplementation with omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFA) could attenuate both the severity and frequency of aggressive behaviour., Methods: Adult male prisoners who have a history of aggressive behaviour (n = 600) will be recruited from at least 6 Correctional Centres and randomised to receive either n-3 LCPUFA or placebo supplementation for a 16-week duration. Treatment will be with either 1 g/day of n-3 LCPUFA (694 mg DHA and 397 mg EPA) or placebo capsules, which are a corn/soy oil blend and are identical in size and colour. The primary outcome measure is the Inmate Behavioural Observation Scale (IBOS): an objective measure of aggressive behaviour. Secondary outcome measures include questionnaires (including aggression, attention deficit disorder, impulsivity, depression/anxiety/stress scales), engagement in programmes, recidivism and quality of life. Baseline and post-intervention assessments include the IBOS, questionnaires and blood to measure the levels of n-3 LCPUFA., Discussion: To conclusively test the potential that increasing n-3 LCPUFA intakes can improve rates of prisoner aggression and associated mental health and violence-related social system management costs, we propose an adequately powered multi-centre, double-blind, randomised controlled trial, examining the effects of n-3 LCPUFA supplementation on aggressive behaviour in adult male prisoners. If successful, this study will inform prisoner policy with respect to nutrition and by inference contribute to a broader community approach to preventative mental health practices., Trial Registration: Australian New Zealand Clinical Trial Registry (ANZCTR) ACTRN12618001665224 . Registered on 10 October 2018.

There is a lack of evidence to determine if diet quality is associated with cognitive performance in older adults. Therefore, the aim of this study was to examine whether diet quality is associated with cognitive performance among older adults. A cross-sectional, secondary analysis of baseline data from the Hunter Community Study (HCS), comparing diet quality, measured using the Australian Recommended Food Score (ARFS), along with validated cognitive performance instruments the Audio Recorded Cognitive Screen (ARCS) and the Mini-Mental State Examination (MMSE) were undertaken in adults aged 55-85 years, living in Newcastle, NSW, Australia. Adjusted linear regression analyses showed that, compared with the lowest ARFS quintile, those in the highest quintile had an ARCS score 5.883 units greater ( p < 0.001; R 2 = 0.0098). Furthermore, when quintiles of ARFS score were tested against each ARCS sub-scale score, statistically significant associations were observed with the greatest effect for the Memory (β = 4.055; p = 0.001; R 2 = 0.0065) and Attention (β = 4.136; p = 0.002; R 2 = 0.0047) domains. No statistically significant associations were observed between quintiles of ARFS and MMSE score in the adjusted linear regression analyses. In conclusion, a positive association was observed between diet quality and cognitive performance within this sample of older Australian adults. Further investigation of the above association over time, when follow-up data becomes available, in longitudinal analysis is recommended.

Context: Long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFAs) are widely considered as nootropic agents that may be beneficial in reversing cognitive impairment., Objective: The present systematic review of randomized controlled trials was conducted to determine the changes in cognitive function after intervention with LCn-3PUFA supplementation in non-demented adults, including those with mild cognitive impairment., Data Sources: Five databases (MEDLINE, CINAHL, Scopus, EMBASE, and the Cochrane Library) were searched systematically along with reference lists of selected articles., Study Selection: Studies were eligible for inclusion if they measured the effect of LCn-3PUFA supplementation on cognition in non-demented adults., Data Extraction: A total of 787 records were screened, of which 25 studies were eligible for inclusion. Treatment effects were summarized as global cognitive function for primary outcome and measured using the Mini-Mental State Examination and individual cognitive domains for secondary outcome. The pooled effect sizes were estimated using Hedge's g and random-effects modeling., Data Analysis: Results from randomized controlled trials indicate that LCn-3PUFAs have no effect on global cognitive function (Hedge's g = 0.02; 95% confidence interval, -0.12 to 0.154), and among the specific cognitive domains, only memory function showed a mild benefit (Hedge's g = 0.31; P = 0.003; z = 2.945)., Conclusion: The existing literature suggests that LCn-3PUFA supplementation could provide a mild benefit in improving memory function in non-demented older adults., Systematic Review Registration: PROSPERO registration no. CRD42017078664., (© The Author(s) 2019. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Cognitive impairment is common in multiple sclerosis (MS) but not adequately monitored by Expanded Disability Status Scale assessment. The Audio Recorded Cognitive Screen (ARCS) and Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) are easy-to-use tools to assess cognitive function in clinical practice., Objective: To compare the sensitivity of ARCS to BICAMS and their relative predictive value for employment status., Methods: MS patients and healthy controls were assessed using the ARCS and the BICAMS consecutively. Receiver Operating Characteristic (ROC) curve analyses were used to compare the two tests. A step-wise, logistic regression analysis was used to identify the cognitive test(s) that best predicted employment status and quality of life., Results: Total ARCS, memory and attention domain scores were moderately correlated with all BICAMS tests (r = 0.3-0.5; P ≤ 0.05). Total ARCS predicts cognitive impairment with good sensitivity and specificity relative to the BICAMS tests (AUC = 0.8; P = 0.00045). Total ARCS detects higher levels of impairment than BICAMS in MS patients (44% versus 21%). The memory domain of the ARCS and the BVMT-R were the best predictors of employment status (OR = 1.12 and 1.14, P < 0.05)., Conclusion: BICAMS and ARCS have comparable sensitivity for cognitive impairment in MS. Memory assessment from either tests is the best predictor of employment status; however, the BICAMS is a better predictor of work productivity., (Crown Copyright © 2020. Published by Elsevier B.V. All rights reserved.)

Background: Monitoring for cognitive deficits during a course of electroconvulsive therapy (ECT) is recommended, but cognitive assessment can be time consuming. The Audio Recorded Cognitive Screen (ARCS) is a cognitive test instrument with good psychometric properties that places minimal demands on clinicians' time, but until now, it has not been formally evaluated for monitoring cognition in the context of ECT treatment., Objectives: This study aimed to assess the feasibility/utility of using the ARCS in the assessment of depressed patients undergoing ECT., Methods: Depressed patients undergoing ECT were tested with the ARCS and a comparison instrument, the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), in counterbalance order immediately before any ECT and after the sixth ECT treatment episode. Apathy (Apathy Scale) and depression (Profile of Mood states Short Form) were measured on both occasions. Analyses compared performances on the 2 cognitive instruments and examined for associations with the measures of apathy or depression., Results: Twenty-eight individuals (9 male, 19 female) aged 19 to 84 years underwent testing. Performances on the total ARCS were similar to those on the total RBANS, and both showed decline from baseline to follow-up. The total ARCS and RBANS measures correlated well (r = 0.75, P < 0.001). Neither apathy nor depression scores were significantly associated with scores on either the RBANS or ARCS., Conclusions: The ARCS was acceptable and convenient in the assessment of cognition in patients undergoing treatment with ECT. In light of its practical advantages, further evaluation of the ARCS for detecting cognitive impairment and tracking cognitive changes during ECT seems warranted.

Background: Anticholinergic challenge can induce odor identification impairment that indicates Alzheimer's disease (AD) pathology, and short-term change in odor identification impairment with cholinesterase inhibitor (CheI) treatment may predict longer term cognitive outcomes., Objective: In patients with mild cognitive impairment (MCI) treated prospectively with donepezil, a CheI, for 52 weeks, to determine if 1) acute decline in odor identification ability with anticholinergic challenge can predict cognitive improvement, and 2) change in odor identification over 8 weeks can predict cognitive improvement., Methods: MCI was diagnosed clinically without AD biomarkers. At baseline, the University of Pennsylvania Smell identification Test (UPSIT) was administered before and after an anticholinergic atropine nasal spray challenge. Donepezil was started at 5 mg daily, increased to 10 mg daily if tolerated, and this dose was maintained for 52 weeks. Main outcomes were ADAS-Cog total score and Selective Reminding Test (SRT) total immediate recall score measured at baseline, 26 and 52 weeks., Results: In 100 study participants, mean age 70.14 (SD 9.35) years, atropine-induced decrease in UPSIT score at baseline was not associated with change in ADAS-Cog or SRT scores over 52 weeks. Change in UPSIT score from 0 to 8 weeks did not show a significant association with change in the ADAS-Cog or SRT measures over 52 weeks., Conclusion: These negative findings in a relatively large sample of patients with MCI did not replicate results in much smaller samples. Change in odor identification with anticholinergic challenge, and over 8 weeks, may not be useful predictors of cognitive improvement with CheI in patients with MCI.

Background: Psychosis is more prevalent among people in prison compared with the community. Early detection is important to optimise health and justice outcomes; for some, this may be the first time they have been clinically assessed., Aims: Determine factors associated with a first diagnosis of psychosis in prison and describe time to diagnosis from entry into prison., Method: This retrospective cohort study describes individuals identified for the first time with psychosis in New South Wales (NSW) prisons (2006-2012). Logistic regression was used to identify factors associated with a first diagnosis of psychosis. Cox regression was used to describe time to diagnosis from entry into prison., Results: Of the 38 489 diagnosed with psychosis for the first time, 1.7% (n = 659) occurred in prison. Factors associated with an increased likelihood of being diagnosed in prison (versus community) were: male gender (odds ratio (OR) = 2.27, 95% CI 1.79-2.89), Aboriginality (OR = 1.81, 95% CI 1.49-2.19), older age (OR = 1.70, 95% CI 1.37-2.11 for 25-34 years and OR = 1.63, 95% CI 1.29-2.06 for 35-44 years) and disadvantaged socioeconomic area (OR = 4.41, 95% CI 3.42-5.69). Eight out of ten were diagnosed within 3 months of reception., Conclusions: Among those diagnosed with psychosis for the first time, only a small number were identified during incarceration with most identified in the first 3 months following imprisonment. This suggests good screening processes are in place in NSW prisons for detecting those with serious mental illness. It is important these individuals receive appropriate care in prison, have the opportunity to have matters reheard and possibly diverted into treatment, and are subsequently connected to community mental health services on release., Declaration of Interest: None.

Convincing evidence exists for the positive effect of an improvement in diet quality on age-related cognitive decline, in part due to dietary fatty acid intake. A cross-sectional analysis of data from the Hunter Community Study (HCS) ( n = 2750) was conducted comparing dietary data from a validated Food Frequency Questionnaire (FFQ) with validated cognitive performance measures, Audio Recorded Cognitive Screen (ARCS) and Mini Mental State Examination (MMSE). Adjusted linear regression analysis found statistically significant associations between dietary intake of total n-6 fatty acids (FA), but no other FAs, and better cognitive performance as measured by the ARCS (RC = 0.0043; p = 0.0004; R ² = 0.0084). Multivariate regression analyses of n-6 FA intakes in quartiles showed that, compared with the lowest quartile (179.8⁻1150.3 mg), those in the highest quartile (2315.0⁻7449.4 mg) had a total ARCS score 2.1 units greater (RC = 10.60466; p = 0.006; R ² = 0.0081). Furthermore, when n-6 FA intake was tested against each of the ARCS domains, statistically significant associations were observed for the Fluency (RC = 0.0011432; p = 0.007; R ² = 0.0057), Visual (RC = 0.0009889; p = 0.034; R ² = 0.0050), Language (RC = 0.0010651; p = 0.047; R ² = 0.0068) and Attention (RC = 0.0011605; p = 0.017; R ² = 0.0099) domains, yet there was no association with Memory (RC = -0.000064; p = 0.889; R ² = 0.0083). No statistically significant associations were observed between FA intakes and MMSE. A higher intake of total n-6 FA, but not other types of FA, was associated with better cognitive performance among a representative sample of older aged Australian adults.

Background: The police attend numerous domestic violence events each year, recording details of these events as both structured (coded) data and unstructured free-text narratives. Abuse types (including physical, psychological, emotional, and financial) conducted by persons of interest (POIs) along with any injuries sustained by victims are typically recorded in long descriptive narratives., Objective: We aimed to determine if an automated text mining method could identify abuse types and any injuries sustained by domestic violence victims in narratives contained in a large police dataset from the New South Wales Police Force., Methods: We used a training set of 200 recorded domestic violence events to design a knowledge-driven approach based on syntactical patterns in the text and then applied this approach to a large set of police reports., Results: Testing our approach on an evaluation set of 100 domestic violence events provided precision values of 90.2% and 85.0% for abuse type and victim injuries, respectively. In a set of 492,393 domestic violence reports, we found 71.32% (351,178) of events with mentions of the abuse type(s) and more than one-third (177,117 events; 35.97%) contained victim injuries. "Emotional/verbal abuse" (33.46%; 117,488) was the most common abuse type, followed by "punching" (86,322 events; 24.58%) and "property damage" (22.27%; 78,203 events). "Bruising" was the most common form of injury sustained (51,455 events; 29.03%), with "cut/abrasion" (28.93%; 51,284 events) and "red marks/signs" (23.71%; 42,038 events) ranking second and third, respectively., Conclusions: The results suggest that text mining can automatically extract information from police-recorded domestic violence events that can support further public health research into domestic violence, such as examining the relationship of abuse types with victim injuries and of gender and abuse types with risk escalation for victims of domestic violence. Potential also exists for this extracted information to be linked to information on the mental health status., (©George Karystianis, Armita Adily, Peter W Schofield, David Greenberg, Louisa Jorm, Goran Nenadic, Tony Butler. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 12.03.2019.)

Head injury, particularly that resulting in brain injury, is a significant public health concern. For example, annual incidence rates of traumatic brain injury, a common consequence of head injury, range from 54 to 60 million people worldwide, including 2.2-3.6 million people whose trauma is moderate to severe. Trauma to the face and brain, including blast injuries common in modern warfare, can result in alterations in the ability to both smell and taste. In the case of smell, these include total loss of function (anosmia), decreased sensitivity (hyposmia), alterations in odor quality (dysosmia), and hallucination (phantosmia). Although taste dysfunction, i.e., altered perception of such basic taste-bud-mediated sensations as sweet, sour, bitter, salty, and savory (umami), can be similarly influenced by head trauma, the effects are typically more subtle and less studied. The present review provides an up-to-date assessment of what is known about the impact of head injury on quantitative measures of taste and smell function, including the influences of severity, type of injury, location of insults, prognosis, and approaches to therapy., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Primary Objective: To identify correlates of past traumatic brain injury (TBI) in a population of young offenders., Research Design: Cross-sectional analyses were conducted on available data from a sample derived from the NSW Young People on Community Orders Health Survey., Procedures: Study participants were administered questionnaires to collect history relating to past TBI, childhood trauma, substance abuse, and psychological/psychiatric symptoms and underwent assessments of intellectual functioning. Information on offending history was accessed through Juvenile Justice administrative records., Outcomes and Results: Analyses were undertaken on data from 788 young offenders (672 males and 116 females). A past TBI was reported in 39%. Symptoms of psychological distress were more prevalent in females. A history of TBI was associated with more symptoms on a Childhood Trauma Questionnaire, as well as higher psychological distress (K-10), and higher levels on standardized measures of anger/violence, post-traumatic stress, and substance abuse., Conclusions: The experience of early life trauma warrants further consideration as an antecedent to both childhood TBI and offending which might account for some of the previously observed association of mild TBI with subsequent offending behavior.

General cognitive function is a prominent and relatively stable human trait that is associated with many important life outcomes. We combine cognitive and genetic data from the CHARGE and COGENT consortia, and UK Biobank (total N = 300,486; age 16-102) and find 148 genome-wide significant independent loci (P < 5 × 10 -8 ) associated with general cognitive function. Within the novel genetic loci are variants associated with neurodegenerative and neurodevelopmental disorders, physical and psychiatric illnesses, and brain structure. Gene-based analyses find 709 genes associated with general cognitive function. Expression levels across the cortex are associated with general cognitive function. Using polygenic scores, up to 4.3% of variance in general cognitive function is predicted in independent samples. We detect significant genetic overlap between general cognitive function, reaction time, and many health variables including eyesight, hypertension, and longevity. In conclusion we identify novel genetic loci and pathways contributing to the heritability of general cognitive function.

Objective: To evaluate the individual- and population-level impact of a combination of factors, including traumatic brain injury (TBI) and certain maternal characteristics, on subsequent criminal conviction., Design and Participants: A retrospective record linkage study involving a cohort of 30 599 individuals born between 1980 and 1985, with ratio of 1 (with TBI): 3 (no TBI), matched by sex and the year of birth., Methods and Procedures: Cox proportional hazard regression models and population attributable risk percentages (PAR%) were used to assess the contribution of TBI and other risk factors on subsequent criminal convictions., Main Outcomes and Results: Overall, individuals born to the teenaged mothers (<20 years) have significantly higher proportion of TBI than those born to older mothers (35% vs 22%; P < .001). In the gender-specific analyses, a history of TBI was associated with increased risk for criminal convictions (adjusted hazard ratio [aHR]: 1.48, 95% confidence interval [CI]: 1.36-1.60, and aHR: 1.45, 95% CI: 1.22-1.73, for men and women, respectively). Maternal characteristics (maternal age, single parent, multiparity) were identified as the greater contributor to the criminal convictions (PAR%: 57% and 67% for men and women, respectively). The combined impact of mental illness, maternal factors, and TBI was estimated to be 67% and 74% (for men and women, respectively); with nonoverlapping 95% CIs for PAR%, these factors were estimated to have had a higher impact among females than among males., Conclusion: More than half of the criminal convictions were associated with a relatively small number of risk factors, including poor mental health, low socioeconomic status, and TBI as well as certain maternal characteristics.

Apolipoproteins play a crucial role in lipid metabolism with implications in cardiovascular disease, obesity, diabetes, Alzheimer's disease, and longevity. We quantified 7 apolipoproteins in plasma in 1067 individuals aged 56-105 using immunoassays and explored relationships with APOE polymorphism ε2/3/4, vascular health, frailty, and cognition. ApoA1, ApoA2, ApoB, ApoC3, ApoE, ApoH, and ApoJ decreased from mid-life, although ApoE and ApoJ had U-shaped trends. Centenarians had the highest ApoE levels and the lowest frequency of APOE ε4 allele relative to younger groups. Apolipoprotein levels trended lower in APOE ε4 homozygotes and heterozygotes compared with noncarriers, with ApoE and ApoJ being significantly lower. Levels of all apolipoproteins except ApoH were higher in females. Sex- and age-related differences were apparent in the association of apolipoproteins with cognitive performance, as only women had significant negative associations of ApoB, ApoE, ApoH, and ApoJ in mid-life, whereas associations at older age were nonsignificant or positive. Our findings suggest levels of some apolipoproteins, especially ApoE, are associated with lifespan and cognitive function in exceptionally long-lived individuals., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The aim of this study was to examine brain neurometabolite concentrations in retired rugby league players who had a history of numerous self-reported concussions. Participants were 16 retired professional rugby league players (ages 30-45 years) with an extensive history of concussion and participation in contact sports, and 16 age- and education-matched controls who had no history of neurotrauma or participation in contact sports. All completed a clinical interview, psychological and cognitive testing, and magnetic resonance spectroscopy (MRS) investigation. MRS voxels were placed in posterior cingulate grey matter and parietal white matter. Neurometabolite concentrations were quantified using LCModel. It was hypothesized that retired athletes would differ on N-acetyl aspartate, myo-inositol, choline, glutamate, and glutathione. Retired players had significantly lower concentrations of grey matter glutathione (p=0.02, d=0.91). They did not significantly differ in concentrations of other neurometabolites. There were no significant differences between groups on measures of depression, anxiety, or cognitive functioning. The retired athletes reported significantly greater alcohol use (p<0.01; Cohen's d=1.49), and they had worse manual dexterity using their non-dominant hand (p=0.03; d=1.08). These preliminary findings suggest that MRS might be modestly sensitive to biochemical differences in athletes after their athletic careers have ended in the absence of clinical differences in cognitive performance and self-reported psychological functioning., (© Georg Thieme Verlag KG Stuttgart · New York.)

Neurological and psychological symptoms in multiple sclerosis can affect cognitive function. The objective of this study was to explore the relationship between psychological measures and cognitive performance in a patient cohort. In 322 multiple sclerosis patients, psychological symptoms were measured using the Depression Anxiety and Stress Scale, and cognitive function was evaluated using Audio Recorded Cognitive Screen. Multifactor linear regression analysis, accounting for all clinical covariates, found that anxiety was the only psychological measure to remain a significant predictor of cognitive performance (p<0.001), particularly memory function (p<0.001). Further prospective studies are required to determine whether treatment of anxiety improves cognitive impairment.

Background: Anticholinergic challenge can induce odor identification impairment that indicates Alzheimer's disease pathology., Objective: To determine if decline in odor identification ability with anticholinergic challenge can predict improvement with donepezil, a cholinesterase inhibitor (ChEI), in patients with mild cognitive impairment (MCI)., Methods: At baseline, the University of Pennsylvania Smell identification Test (UPSIT) was administered before and after an anticholinergic atropine nasal spray challenge. Donepezil was started at 5 mg daily, increased to 10 mg daily if tolerated, and then the dose was kept constant for 52 weeks. Main outcomes were change in Selective Reminding Test (SRT) total immediate recall and ADAS-Cog total score from baseline to 26 and 52 weeks., Results: In 37 participants, mean age 70.4 (SD 9.8) y, greater atropine-induced decrease in UPSIT score at baseline was associated with greater improvement in SRT total recall score from baseline to 26 and 52 weeks (p < 0.03). This effect remained after adjusting for time, age, education, gender, APOE ɛ4 status, and baseline cognitive score (p < 0.05). Decrease in UPSIT score was associated with global improvement (CIBIC-plus) over 52 weeks (p < 0.02). After excluding patients with congential anosmia, increase in UPSIT score from 0 to 8 weeks showed a trend-level association with improvement on the ADAS-Cog (p = 0.07)., Conclusions: Anticholinergic challenge-induced odor identification decline was associated with cognitive improvement, and short-term improvement in odor identification tended to predict longer term cognitive improvement. These simple inexpensive strategies have the potential to improve selection of patients with MCI for ChEI treatment.

Background: The aim of the study was to determine how much of the association between obesity, measured by body mass index (BMI), and cognition in older persons is mediated through inflammation, fasting plasma glucose, and hypertriglyceridemia., Methods: Anthropometrics, high-sensitivity C-reactive protein (CRP), fasting plasma glucose, and serum triglycerides were measured in 3,256 community-dwelling individuals aged 55-85 years residing in Newcastle, New South Wales, Australia. Audio recorded cognitive screen (ARCS) was used to assess multiple cognitive domains., Results: Mediation analyses showed very modest but significant direct mediation effects, whereby obesity was associated with better cognitive function after adjusting for potential confounders (controlled direct effect ≈ 1/500 point increase in the total ARCS score per 1.0-kg/m 2 increase in BMI). There were significant indirect negative mediation effects from BMI to cognition mediated through CRP, that is, increased BMI was associated with increased CRP which was associated with decreased cognition (natural indirect effect -0.20 unit; 95% confidence interval [CI] -0.39, -0.02), and through fasting plasma glucose, that is, increased BMI was associated with increased fasting plasma glucose which was associated with decreased cognition (natural indirect effect -0.12 unit; 95% CI -0.24, -0.01], but not through serum triglycerides., Conclusions: There is a weak positive association between obesity and cognitive performance in older persons, which is partially antagonized by inflammation and elevated fasting plasma glucose, but not hypertriglyceridemia. Further studies are needed to elucidate whether this is due to selection bias, or truly reflects biologically complex and counter balancing pathways involved in obesity., (© The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Apolipoprotein H (ApoH) is a multi-functional plasma glycoprotein that has been associated with negative health outcomes. ApoH levels have high heritability. We undertook a genome-wide association study of ApoH levels using the largest sample to date and replicated the results in an independent cohort (total N = 1,255). In the discovery phase, a meta-analysis of two cohorts, the Sydney Memory and Ageing Study (Sydney MAS) and the Older Australian Twins Study (OATS) (n = 942) revealed genome-wide significant results in or near the APOH gene on chromosome 17 (top SNP, rs7211380, p = 1 × 10(-11)). The results were replicated in an independent cohort, the Hunter Community Study (p < 0.002) (n = 313). Conditional and joint analysis (COJO) confirmed the association of the chromosomal 17 region with ApoH levels. The set of independent SNPs identified by COJO explained 23% of the variance. The relationships between the top SNPs and cardiovascular/lipid/cognition measures and diabetes were assessed in Sydney MAS, with suggestive results observed for diabetes and cognitive performance. However, replication of these results in the smaller OATS cohort was not found. This work provides impetus for future research to better understand the contribution of genetics to ApoH levels and its possible impacts on health.

Objective: This study investigated the ability of the Audio Recorded Cognitive Screen (ARCS) to detect cognitive deficit in individuals with schizophrenia, relative to the Mini Mental State Examination (MMSE) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), and explored the associations between the ARCS and functional outcomes. We hypothesised that the ARCS would be able to better discriminate between individuals with schizophrenia and healthy controls than the MMSE, and that ARCS performance would be correlated with measures of social and vocational functioning., Methods: The participants were 19 community-dwelling individuals with schizophrenia or schizoaffective disorder and 19 healthy controls recruited from the Australian Schizophrenia Research Bank (ASRB). Participants completed the ARCS, MMSE, and self-report measures of social and vocational functioning. Clinical and diagnostic data stored by the ASRB were also utilised., Results: The schizophrenia group performed worse than the control group on the ARCS, with memory, t(36)=2.49, p=0.02, 95% CI [-1.84, -18.79] and fluency, t(36)=2.40, p=0.02, 95% CI [-1.87, -22.24] domains being the main discriminating measures. The RBANS also discriminated between the two groups, and ARCS and RBANS total scores were moderately to strongly correlated. There was no difference between the two groups on the MMSE after controlling for demographic variables. ARCS performance was associated with employment status [χ2(1)=7.16, p=0.007]., Conclusion: The ARCS may be sensitive to the cognitive deficits in outpatients with schizophrenia and an indicator of functional outcomes in this population.

Background: Traumatic brain injury (TBI) may be a risk factor for criminal behaviour however multiple factors potentially confound the association., Methods: Record linkage and Cox proportional hazards regression analyses were used to examine the association between hospital-recorded TBI (n = 7,694) and subsequent first criminal conviction in a retrospective cohort matched 1:3 with 22,905 unaffected community controls and full-sibling controls (n = 2,397). Aboriginality, substance abuse, social disadvantage, and mental illness were included in analyses as potential confounders., Results: In multivariable models, relative to general population controls, TBI was associated with any conviction (males: Hazard Ratio (HR) = 1.58 (95% CI 1.46 to 1.72); females: HR = 1.52 (95% CI 1.28 to 1.81)); and similar Hazard Ratios were obtained for the sibling analyses in males (HR = 1.68 (95% CI 1.31-2.18)) and females (HR 1.27 (95% CI 0.71-2.29)). TBI was also associated with violent convictions relative to the general population, (males: HR = 1.65 (95% CI 1.42 to 1.92); females HR = 1.73 (95% CI 1.21 to 2.47)), and in analyses with sibling controls in men (HR = 1.89 (95% CI 1.20-3.00)), but not in women (HR 0.73, 95% CI 0.29-1.81))., Conclusion: The results support a modest causal link between TBI and criminality after comprehensive adjustment for confounding. Reducing the rate of TBI, a major public health imperative, might have benefits in terms of crime reduction.

Objectives: Concussion remains one of the inherent risks of participation in rugby league. While other injuries incurred by rugby league players have been well studied, less focus and attention has been directed towards concussion., Review Method: The current review examined all articles published in English from 1900 up to June 2013 pertaining to concussion in rugby league players., Data Sources: Publications were retrieved via six databases using the key search terms: rugby league, league, football; in combination with injury terms: athletic injuries, concussion, sports concussion, sports-related concussion, brain concussion, brain injury, brain injuries, mild traumatic brain injury, mTBI, traumatic brain injury, TBI, craniocerebral trauma, head injury and brain damage. Observational, cohort, correlational, cross-sectional and longitudinal studies were all included., Results: 199 rugby league injury publications were identified. 39 (20%) were related in some way to concussion. Of the 39 identified articles, 6 (15%) had the main aim of evaluating concussion, while the other 33 reported on concussion incidence as part of overall injury data analyses. Rugby league concussion incidence rates vary widely from 0.0 to 40.0/1000 playing hours, depending on the definition of injury (time loss vs no time loss). The incidence rates vary across match play versus training session, seasons (winter vs summer) and playing position (forwards vs backs). The ball carrier has been found to be at greater risk for injury than tacklers. Concussion accounts for 29% of all injuries associated with illegal play, but only 9% of injuries sustained in legal play., Conclusions: In comparison with other collision sports, research evaluating concussion in rugby league is limited. With such limited published rugby league data, there are many aspects of concussion that require attention, and future research may be directed towards these unanswered questions., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)