Impact of early intervention on the population prevalence of common mental disorders: 20-year prospective study.

BACKGROUND: The potential for early interventions to reduce the later prevalence of common mental disorders (CMD) first experienced in adolescence is unclear. AIMS: To examine the course of CMD and evaluate the extent to which the prevalence of CMD could be reduced by preventing adolescent CMD, or by intervening to change four young adult processes, between the ages of 20 and 29 years, that could be mediating the link between adolescent and adult disorder. METHOD: This was a prospective cohort study of 1923 Australian participants assessed repeatedly from adolescence (wave 1, mean age 14 years) to adulthood (wave 10, mean age 35 years). Causal mediation analysis was undertaken to evaluate the extent to which the prevalence of CMD at age 35 years in those with adolescent CMD could be reduced by either preventing adolescent CMD, or by intervening on four young adult mediating processes: the occurrence of young adult CMD, frequent cannabis use, parenting a child by age 24 years, and engagement in higher education and employment. RESULTS: At age 35, 19.2% of participants reported CMD; a quarter of these participants experienced CMD during both adolescence and young adulthood. In total, 49% of those with CMD during both adolescence and young adulthood went on to report CMD at age 35 years. Preventing adolescent CMD reduced the population prevalence at age 35 years by 3.9%. Intervening on all four young adult processes among those with adolescent CMD, reduced this prevalence by 1.6%. CONCLUSIONS: In this Australian cohort, a large proportion of adolescent CMD resolved by adulthood, and by age 35 years, the largest proportion of CMD emerged among individuals without prior CMD. Time-limited, early intervention in those with earlier adolescent disorder is unlikely to substantially reduce the prevalence of CMD in midlife.

The Victorian Intergenerational Health Cohort Study (VIHCS): Study design of a preconception cohort from parent adolescence to offspring childhood.

BACKGROUND: There is increasing evidence that parental determinants of offspring early life development begin well before pregnancy. OBJECTIVES: We established the Victorian Intergenerational Health Cohort Study (VIHCS) to examine the contributions of parental mental health, substance use, and socio-economic characteristics before pregnancy to child emotional, physical, social, and cognitive development. POPULATION: Men and women were recruited from the Victorian Adolescent Health Cohort (VAHCS), an existing cohort study beginning in 1992 that assessed a representative sample of 1943 secondary school students in Victoria, Australia, repeatedly from adolescence (wave 1, mean age 14 years) to adulthood (wave 10, mean age 35 years). METHODS: Victorian Adolescent Health Cohort participants with children born between 2006 and 2013 were recruited to VIHCS and invited to participate during trimester three, at 2 months postpartum, and 1 year postpartum. Parental mental health, substance use and socio-economic characteristics were assessed repeatedly throughout; infant characteristics were assessed postnatally and in infancy. Data will be supplemented by linkage to routine datasets. A further follow-up is underway as children reach 8 years of age. PRELIMINARY RESULTS: Of the 1307 infants born to VAHCS participants between 2006 and 2013, 1030 were recruited to VIHCS. At VIHCS study entry, 18% of recruited parents had preconception common mental disorder in adolescence and young adulthood, 18% smoked daily in adolescence and young adulthood, and 6% had not completed high school. Half of VIHCS infants were female (48%), 4% were from multiple births, and 7% were preterm (<37 weeks' gestation). CONCLUSIONS: Victorian Intergenerational Health Cohort Study is a prospective cohort of 1030 children with up to nine waves of preconception parental data and three waves of perinatal parental and infant data. These will allow examination of continuities of parental health and health risks from the decades before pregnancy to offspring childhood, and the contributions of exposures before pregnancy to offspring outcomes in childhood.

Does adolescent heavier alcohol use predict young adult aggression and delinquency? Parallel analyses from four Australasian cohort studies.

While the association between heavy alcohol consumption and aggression has been well documented, the causal direction of this association, particularly at a population level, is disputed. A number of causal sequences have been proposed. First, that aggression leads to heavy alcohol use. Second, that heavy alcohol use leads to aggression. Third, that the association between alcohol use and aggression is due to confounding by (a) sociodemographic variables or (b) delinquency. We report here data from four Australasian prospective longitudinal studies of adolescents, to assess the temporal sequence of heavy drinking and aggression over the period from adolescence to young adulthood. The four cohort studies provide a total sample of 6,706 persons (Australian Temperament Project, n = 1701; Christchurch Health and Development Study, n = 931; Mater-University of Queensland Study of Pregnancy, n = 2437; Victorian Adolescent Health Cohort Study, n = 1637). We use multinomial logistic regression to determine whether early adolescent aggression predicts subsequent age of onset of heavy episodic drinking (HED), after adjustment for concurrent sociodemographic factors and delinquency. We then consider whether HED predicts subsequent aggression, after adjusting for past aggression, concurrent delinquency, and a range of confounders. There are broadly consistent findings across the four cohort studies. Early aggression strongly predicts subsequent HED. HED predicts later aggression after adjustment for prior aggression and other confounders. Policies that alter population levels of alcohol consumption are likely to impact on levels of aggression in societies where HED linked to aggression is more common.

Prediction of perinatal depression from adolescence and before conception (VIHCS): 20-year prospective cohort study.

BACKGROUND: Perinatal depression is a neglected global health priority, affecting 10-15% of women in high-income countries and a greater proportion in low-income countries. Outcomes for children include cognitive, behavioural, and emotional difficulties and, in low-income settings, perinatal depression is associated with stunting and physical illness. In the Victorian Intergenerational Health Cohort Study (VIHCS), we aimed to assess the extent to which women with perinatal depressive symptoms had a history of mental health problems before conception. METHODS: VIHCS is a follow-up study of participants in the Victorian Adolescent Health Cohort Study (VAHCS), which was initiated in August, 1992, in the state of Victoria, Australia. In VAHCS, participants were assessed for health outcomes at nine timepoints (waves) from age 14 years to age 29 years. Depressive symptoms were measured with the Revised Clinical Interview Schedule and the General Health Questionnaire. Enrolment to VIHCS began in September, 2006, during the ninth wave of VAHCS; depressive symptoms at this timepoint were measured with the Composite International Diagnostic Interview. We contacted women every 6 months (from age 29 years to age 35 years) to identify any pregnancies. We assessed perinatal depressive symptoms with the Edinburgh Postnatal Depression Scale (EPDS) by computer-assisted telephone interview at 32 weeks of gestation, 8 weeks after birth, and 12 months after birth. We defined perinatal depression as an EPDS score of 10 or more. FINDINGS: From a stratified random sample of 1000 female participants in VAHCS, we enrolled 384 women with 564 pregnancies. 253 (66%) of these women had a previous history of mental health problems at some point in adolescence or young adulthood. 117 women with a history of mental health problems in both adolescence and young adulthood had 168 pregnancies, and perinatal depressive symptoms were reported for 57 (34%) of these pregnancies, compared with 16 (8%) of 201 pregnancies in 131 women with no preconception history of mental health problems (adjusted odds ratio 8·36, 95% CI 3·34-20·87). Perinatal depressive symptoms were reported at one or more assessment points in 109 pregnancies; a preconception history of mental health problems was reported in 93 (85%) of these pregnancies. INTERPRETATION: Perinatal depressive symptoms are mostly preceded by mental health problems that begin before pregnancy, in adolescence or young adulthood. Women with a history of persisting common mental disorders before pregnancy are an identifiable high-risk group, deserving of clinical support throughout the childbearing years. Furthermore, the window for considering preventive intervention for perinatal depression should extend to the time before conception. FUNDING: National Health and Medical Research Council (Australia), Victorian Health Promotion Foundation, Colonial Foundation, Australian Rotary Health Research and Perpetual Trustees.

Cannabis Use in Adolescence and Young Adulthood: A Review of Findings from the Victorian Adolescent Health Cohort Study.

The Victorian Adolescent Health Cohort Study (VAHCS) is a long-term Australian cohort study that has documented cannabis use in young Australians from the mid-teens to the mid-30s. The study findings have described the natural history of early cannabis use, remission, and escalation and the social and mental health consequences of different patterns of use. The adverse consequences of cannabis use are most clear-cut in heavy early adolescent users. These consequences include educational failure, persisting mental health problems, and progression to other substance use. For later onset and occasional users, the risks are lower and appear to entail modest elevations in risk for other drug use compared with never users. With growing evidence of health consequences, there is a strong case for actions around early heavy adolescent users. Prevention of early use, identification and treatment of early heavy users, and harm reduction through diversion of early heavy users away from the custodial justice system into health care are all priority responses.

Deaths in young people aged 0-24 years in the UK compared with the EU15+ countries, 1970-2008: analysis of the WHO Mortality Database.

BACKGROUND: Concern is growing that mortality and health in children and young people in the UK lags behind that of similar countries. METHODS: We analysed death registry data provided to the WHO Mortality Database to compare UK mortality for children and young people aged 0-24 years with that of European Union member states (before May, 2004, excluding the UK, plus Australia, Canada, and Norway [the EU15+ countries]) from 1970 to 2008 using the WHO World Mortality Database. We grouped causes of death by Global Burden of Disease classification: communicable, nutritional, or maternal causes; non-communicable disorders; and injury. UK mortality trends were compared with quartiles of mortality in EU15+ countries. We used quasi-likelihood Poisson models to explore differences between intercepts and slopes between the UK and the EU15+ countries. FINDINGS: In 1970, UK total mortality was in the best EU15+ quartile (<25th centile) for children and young people aged 1-24 years, with UK infant mortality similar to the EU15+ median. Subsequent mortality reductions in the UK were smaller than were those in the EU15+ countries in all age groups. By 2008, total mortality for neonates, infants, and children aged 1-4 years in the UK was in the worst EU15+ quartile (>75th centile). In 2008, UK annual excess mortality compared with the EU15+ median was 1035 deaths for infants and 134 for children aged 1-9 years. Mortality from non-communicable diseases in the UK fell from being roughly equivalent to the EU15+ median in 1970 to the worst quartile in all age groups by 2008, with 446 annual excess deaths from non-communicable diseases in the UK (280 for young people aged 10-24 years) in 2008. UK mortality from injury remained in the best EU15+ quartile for the study period in all age groups. INTERPRETATION: The UK has not matched the gains made in child, adolescent, and young adult mortality by other comparable countries in the 40 years since 1970, particularly for infant deaths and mortality from non-communicable diseases, including neuropsychiatric disorders. The UK needs to identify and address amenable social determinants and health system factors that lead to poor health outcomes for infants and for children and young people with chronic disorders. FUNDING: None.

The prognosis of common mental disorders in adolescents: a 14-year prospective cohort study.

BACKGROUND: Most adults with common mental disorders report their first symptoms before 24 years of age. Although adolescent anxiety and depression are frequent, little clarity exists about which syndromes persist into adulthood or resolve before then. In this report, we aim to describe the patterns and predictors of persistence into adulthood. METHODS: We recruited a stratified, random sample of 1943 adolescents from 44 secondary schools across the state of Victoria, Australia. Between August, 1992, and January, 2008, we assessed common mental disorder at five points in adolescence and three in young adulthood, commencing at a mean age of 15.5 years and ending at a mean age of 29.1 years. Adolescent disorders were defined on the Revised Clinical Interview Schedule (CIS-R) at five adolescent measurement points, with a primary cutoff score of 12 or higher representing a level at which a family doctor would be concerned. Secondary analyses addressed more severe disorders at a cutoff of 18 or higher. FINDINGS: 236 of 821 (29%; 95% CI 25-32) male participants and 498 of 929 (54%; 51-57) female participants reported high symptoms on the CIS-R (≥12) at least once during adolescence. Almost 60% (434/734) went on to report a further episode as a young adult. However, for adolescents with one episode of less than 6 months duration, just over half had no further common mental health disorder as a young adult. Longer duration of mental health disorders in adolescence was the strongest predictor of clear-cut young adult disorder (odds ratio [OR] for persistent young adult disorder vs none 3.16, 95% CI 1.86-5.37). Girls (2.12, 1.29-3.48) and adolescents with a background of parental separation or divorce (1.62, 1.03-2.53) also had a greater likelihood of having ongoing disorder into young adulthood than did those without such a background. Rates of adolescent onset disorder dropped sharply by the late 20s (0.57, 0.45-0.73), suggesting a further resolution for many patients whose symptoms had persisted into the early 20s. INTERPRETATION: Episodes of adolescent mental disorder often precede mental disorders in young adults. However, many such disorders, especially when brief in duration, are limited to the teenage years, with further symptom remission common in the late 20s. The resolution of many adolescent disorders gives reason for optimism that interventions that shorten the duration of episodes could prevent much morbidity later in life. FUNDING: Australia's National Health and Medical Research Council.

Does the social context of early alcohol use affect risky drinking in adolescents? Prospective cohort study.

BACKGROUND: There are limited longitudinal data on the associations between different social contexts of alcohol use and risky adolescent drinking. METHODS: Australian prospective longitudinal cohort of 1943 adolescents with 6 assessment waves at ages 14-17 years. Drinkers were asked where and how frequently they drank. Contexts were: at home with family, at home alone, at a party with friends, in a park/car, or at a bar/nightclub. The outcomes were prevalence and incidence of risky drinking (≥5 standard drinks (10g alcohol) on a day, past week) and very risky drinking (>20 standard drinks for males and >11 for females) in early (waves 1-2) and late (waves 3-6) adolescence. RESULTS: Forty-four percent (95 % CI: 41-46 %) reported past-week risky drinking on at least one wave during adolescence (waves 1-6). Drinking at a party was the most common repeated drinking context in early adolescence (28 %, 95 % CI 26-30 %); 15 % reported drinking repeatedly (3+ times) with their family in early adolescence (95 % CI: 14-17 %). For all contexts (including drinking with family), drinking 3+ times in a given context was associated with increased the risk of risky drinking in later adolescence. These effects remained apparent after adjustment for potential confounders (e.g. for drinking with family, adjusted RR 1.9; 95 % CI: 1.5-2.4). Similar patterns were observed for very risky drinking. CONCLUSIONS: Our results suggest that consumption with family does not protect against risky drinking. Furthermore, parents who wish to minimise high risk drinking by their adolescent children might also limit their children's opportunities to consume alcohol in unsupervised settings.

The natural history of self-harm from adolescence to young adulthood: a population-based cohort study.

BACKGROUND: Knowledge about the natural history of self-harm is scarce, especially during the transition from adolescence to young adulthood, a period characterised by a sharp rise in self-inflicted deaths. From a repeated measures cohort of a representative sample, we describe the course of self-harm from middle adolescence to young adulthood. METHODS: A stratified, random sample of 1943 adolescents was recruited from 44 schools across the state of Victoria, Australia, between August, 1992, and January, 2008. We obtained data pertaining to self-harm from questionnaires and telephone interviews at seven waves of follow-up, commencing at mean age 15·9 years (SD 0·49) and ending at mean age 29·0 years (SD 0·59). Summary adolescent measures (waves three to six) were obtained for cannabis use, cigarette smoking, high-risk alcohol use, depression and anxiety, antisocial behaviour and parental separation or divorce. FINDINGS: 1802 participants responded in the adolescent phase, with 149 (8%) reporting self-harm, More girls (95/947 [10%]) than boys (54/855 [6%]) reported self-harm (risk ratio 1·6, 95% CI 1·2-2·2). We recorded a substantial reduction in the frequency of self-harm during late adolescence. 122 of 1652 (7%) participants who reported self-harm during adolescence reported no further self-harm in young adulthood, with a stronger continuity in girls (13/888) than boys (1/764). During adolescence, incident self-harm was independently associated with symptoms of depression and anxiety (HR 3·7, 95% CI 2·4-5·9), antisocial behaviour (1·9, 1·1-3·4), high-risk alcohol use (2·1, 1·2-3·7), cannabis use (2·4, 1·4-4·4), and cigarette smoking (1·8, 1·0-3·1). Adolescent symptoms of depression and anxiety were clearly associated with incident self-harm in young adulthood (5·9, 2·2-16). INTERPRETATION: Most self-harming behaviour in adolescents resolves spontaneously. The early detection and treatment of common mental disorders during adolescence might constitute an important and hitherto unrecognised component of suicide prevention in young adults. FUNDING: National Health and Medical Research Council, Australia, and operational infrastructure support programme, Government of Victoria, Australia.

Health of the world's adolescents: a synthesis of internationally comparable data.

Adolescence and young adulthood offer opportunities for health gains both through prevention and early clinical intervention. Yet development of health information systems to support this work has been weak and so far lagged behind those for early childhood and adulthood. With falls in the number of deaths in earlier childhood in many countries and a shifting emphasis to non-communicable disease risks, injuries, and mental health, there are good reasons to assess the present sources of health information for young people. We derive indicators from the conceptual framework for the Series on adolescent health and assess the available data to describe them. We selected indicators for their public health importance and their coverage of major health outcomes in young people, health risk behaviours and states, risk and protective factors, social role transitions relevant to health, and health service inputs. We then specify definitions that maximise international comparability. Even with this optimisation of data usage, only seven of the 25 indicators, covered at least 50% of the world's adolescents. The worst adolescent health profiles are in sub-Saharan Africa, with persisting high mortality from maternal and infectious causes. Risks for non-communicable diseases are spreading rapidly, with the highest rates of tobacco use and overweight, and lowest rates of physical activity, predominantly in adolescents living in low-income and middle-income countries. Even for present global health agendas, such as HIV infection and maternal mortality, data sources are incomplete for adolescents. We propose a series of steps that include better coordination and use of data collected across countries, greater harmonisation of school-based surveys, further development of strategies for socially marginalised youth, targeted research into the validity and use of these health indicators, advocating for adolescent-health information within new global health initiatives, and a recommendation that every country produce a regular report on the health of its adolescents.

Performance analysis of three pilot-scale multi-compartment anaerobic baffled reactors treating domestic wastewater at psychrophilic temperatures in Colorado.

A transition from inefficient aerobic wastewater treatment methods to sustainable approaches is needed. Anaerobic bioreactors are a viable solution as they consume less energy, reduce biosolid production, and provide a source of renewable methane-rich biogas. A barrier to widespread implementation of anaerobic technologies is the lack of design guidance, especially in colder climates. This study bridges this knowledge gap by deriving design principles from three long-running pilot-scale anaerobic baffled reactors (ABRs) operating under psychrophilic conditions. The ABRs removed an average of 56% and 80% chemical oxygen demand (COD) and suspended solids, respectively, with a methane yield of 0.21 L CH4 /g CODrem . Methane production may be improved with increased influent sCOD concentrations and decreased sulfate concentrations. Results suggest that ABRs can treat a range of wastewater strengths accompanied by useable methane production. Despite sharing location, temperature, and HRT, the ABRs displayed distinct performances, highlighting the significance of influent wastewater characteristics. PRACTITIONER POINTS: ABRs achieved 56% and 80% removal efficiencies for COD and suspended solids. Average biogas was 63% methane, and methane yield was 0.21 L CH4 /g CODrem . Volumetric methane production was positively correlated with the influent sCOD/sulfate ratio and negatively correlated with influent sulfate loading.

50-year mortality trends in children and young people: a study of 50 low-income, middle-income, and high-income countries.

BACKGROUND: Global attention has focused on mortality in children younger than 5 years. We analysed global mortality data for people aged 1-24 years across a 50-year period. METHODS: The WHO mortality database was used to obtain mortality data from 1955 to 2004, by age-group (1-4, 5-9, 10-14, 15-19, and 20-24 years) and stratified by sex. To analyse change in mortality, we calculated mortality rates averaged over three 5-year periods (1955-59, 1978-82, and 2000-04) to investigate trends in deaths caused by communicable and non-communicable diseases and injury. FINDINGS: Data were available for 50 countries (ten high income, 22 middle income, eight low income, seven very low income, and three unclassified), grouped as Organisation for Economic Co-operation and Development (OECD) countries, Central and South American countries, eastern European countries and ex-Soviet states, and other countries. In 1955, mortality was highest in the 1-4-year age-group. Across the study period, all-cause mortality reduced by 85-93% in children aged 1-4 years, 80-87% in children aged 5-9 years, and 68-78% in young people aged 10-14 years in OECD, Central and South American, and other countries. Smaller declines (41-48%) were recorded in young men (15-24 years), and by 2000-04, mortality in this group was two-to-three times higher than that in young boys (1-4 years). Mortality in young women (15-24 years) was equal to that of young girls (1-4 years) from 2000 onwards. Substantial declines in death caused by communicable diseases were seen in all age-groups and regions, although communicable and non-communicable diseases remained the main causes of death in children (1-9 years) and young women (10-24 years). Injury was the dominant cause of death in young men (10-24 years) in all regions by the late 1970s. INTERPRETATION: Adolescents and young adults have benefited from the epidemiological transition less than children have, with a reversal of traditional mortality patterns over the past 50 years. Future global health targets should include a focus on the health problems of people aged 10-24 years. FUNDING: None.

Global burden of disease in young people aged 10-24 years: a systematic analysis.

BACKGROUND: Young people aged 10-24 years represent 27% of the world's population. Although important health problems and risk factors for disease in later life emerge in these years, the contribution to the global burden of disease is unknown. We describe the global burden of disease arising in young people and the contribution of risk factors to that burden. METHODS: We used data from WHO's 2004 Global Burden of Disease study. Cause-specific disability-adjusted life-years (DALYs) for young people aged 10-24 years were estimated by WHO region on the basis of available data for incidence, prevalence, severity, and mortality. WHO member states were classified into low-income, middle-income, and high-income countries, and into WHO regions. We estimated DALYs attributable to specific global health risk factors using the comparative risk assessment method. DALYs were divided into years of life lost because of premature mortality (YLLs) and years lost because of disability (YLDs), and are presented for regions by sex and by 5-year age groups. FINDINGS: The total number of incident DALYs in those aged 10-24 years was about 236 million, representing 15·5% of total DALYs for all age groups. Africa had the highest rate of DALYs for this age group, which was 2·5 times greater than in high-income countries (208 vs 82 DALYs per 1000 population). Across regions, DALY rates were 12% higher in girls than in boys between 15 and 19 years (137 vs 153). Worldwide, the three main causes of YLDs for 10-24-year-olds were neuropsychiatric disorders (45%), unintentional injuries (12%), and infectious and parasitic diseases (10%). The main risk factors for incident DALYs in 10-24-year-olds were alcohol (7% of DALYs), unsafe sex (4%), iron deficiency (3%), lack of contraception (2%), and illicit drug use (2%). INTERPRETATION: The health of young people has been largely neglected in global public health because this age group is perceived as healthy. However, opportunities for prevention of disease and injury in this age group are not fully exploited. The findings from this study suggest that adolescent health would benefit from increased public health attention. FUNDING: None.

Young-adult compared to adolescent onset of regular cannabis use: A 20-year prospective cohort study of later consequences.

INTRODUCTION: This paper compares consequences of cannabis use initiated after high school with those of cannabis initiation in adolescence, with estimates of the proportion of adverse consequences accounted for by adult-onset and adolescent-onset cannabis users. METHODS: A state-representative sample in Victoria, Australia (n = 1792) participated in a 10-wave longitudinal study and was followed from age 15 to 35 years. Exposure variable: Patterns of cannabis use across 20 years. Outcomes at age 35: Alcohol use, smoking, illicit drug use, relationship status, financial hardship, depression, anxiety and employment status. RESULTS: Substantially more participants (13.6%) initiated regular use after high school (young-adult onset) than in adolescence (7.7%, adolescent onset). By the mid-30s, both young-adult and adolescent-onset regular users were more likely than minimal/non-users (63.5%) to have used other illicit drugs (odds ratio [OR] > 20.4), be a high-risk alcohol drinker (OR > 3.7), smoked daily (OR > 7.2) and less likely to be in relationships (OR < 0.4). As the prevalence of the young-adult-onset group was nearly double of the adolescent-onset group, it accounted for a higher proportion of adverse consequences than the adolescent-onset group. DISCUSSION AND CONCLUSIONS: Cannabis users who began regular use in their teens had poorer later life outcomes than non-using peers. The larger group who began regular cannabis use after leaving high school accounted for most cannabis-related harms in adulthood. Given the legalisation of cannabis use in an increasing number of jurisdictions, we should increasingly expect harms from cannabis use to lie in those commencing use in young adulthood.

Global patterns of mortality in young people: a systematic analysis of population health data.

BACKGROUND: Pronounced changes in patterns of health take place in adolescence and young adulthood, but the effects on mortality patterns worldwide have not been reported. We analysed worldwide rates and patterns of mortality between early adolescence and young adulthood. METHODS: We obtained data from the 2004 Global Burden of Disease Study, and used all-cause mortality estimates developed for the 2006 World Health Report, with adjustments for revisions in death from HIV/AIDS and from war and natural disasters. Data for cause of death were derived from national vital registration when available; for other countries we used sample registration data, verbal autopsy, and disease surveillance data to model causes of death. Worldwide rates and patterns of mortality were investigated by WHO region, income status, and cause in age-groups of 10-14 years, 15-19 years, and 20-24 years. FINDINGS: 2.6 million deaths occurred in people aged 10-24 years in 2004. 2.56 million (97%) of these deaths were in low-income and middle-income countries, and almost two thirds (1.67 million) were in sub-Saharan Africa and southeast Asia. Pronounced rises in mortality rates were recorded from early adolescence (10-14 years) to young adulthood (20-24 years), but reasons varied by region and sex. Maternal conditions were a leading cause of female deaths at 15%. HIV/AIDS and tuberculosis contributed to 11% of deaths. Traffic accidents were the largest cause and accounted for 14% of male and 5% of female deaths. Other prominent causes included violence (12% of male deaths) and suicide (6% of all deaths). INTERPRETATION: Present global priorities for adolescent health policy, which focus on HIV/AIDS and maternal mortality, are an important but insufficient response to prevent mortality in an age-group in which more than two in five deaths are due to intentional and unintentional injuries. FUNDING: WHO and National Health and Medical Research Council.

Outcomes of occasional cannabis use in adolescence: 10-year follow-up study in Victoria, Australia.

BACKGROUND: Regular adolescent cannabis use predicts a range of later drug use and psychosocial problems. Little is known about whether occasional cannabis use carries similar risks. AIMS: To examine associations between occasional cannabis use during adolescence and psychosocial and drug use outcomes in young adulthood; and modification of these associations according to the trajectory of cannabis use between adolescence and age 20 years, and other potential risk factors. METHOD: A 10-year eight-wave cohort study of a representative sample of 1943 secondary school students followed from 14.9 years to 24 years. RESULTS: Occasional adolescent cannabis users who continued occasional use into early adulthood had higher risks of later alcohol and tobacco dependence and illicit drug use, as well as being less likely to complete a post-secondary qualification than non-users. Those using cannabis at least weekly either during adolescence or at age 20 were at highest risk of drug use problems in young adulthood. Adjustment for smoking in adolescence reduced the association with later educational achievement, but associations with drug use problems remained. CONCLUSIONS: Occasional adolescent cannabis use predicts later drug use and educational problems. Partial mediation by tobacco use raises a possibility that differential peer affiliation may play a role.

Parental mental health before and during pregnancy and offspring birth outcomes: A 20-year preconception cohort of maternal and paternal exposure.

BACKGROUND: Preterm birth (PTB) and small for gestational age (SGA) are increasingly prevalent, with major consequences for health and development into later life. There is emerging evidence that some risk processes begin before pregnancy. We report on associations between maternal and paternal common mental disorders (CMD) before and during pregnancy and offspring PTB and SGA. METHODS: 398 women with 609 infants and 267 men with 421 infants were assessed repeatedly for CMD symptoms before pregnancy between age 14 and 29 and during pregnancy. Associations between preconception and antenatal CMD symptoms and offspring gestational age/PTB and size for gestational age/SGA were estimated using linear and Poisson regression. FINDINGS: In men, persistent preconception CMD across adolescence and young adulthood predicted offspring PTB after adjustment for ethnicity, education, BMI and adolescent substance use (adjusted RR 7·0, 95% CI 1·8,26·8), corresponding to a population attributable fraction of 31% of preterm births. In women, antenatal CMD symptoms predicted offspring PTB (adjusted RR 4·4, 95% CI 1·4,14·1). There was little evidence of associations with SGA. INTERPRETATION: This first report of an association between paternal preconception mental health and offspring gestational age, while requiring replication in larger samples, complements earlier work on stress in animals, and further strengthens the case for expanding preconception mental health care to both men and women. FUNDING: National Health and Medical Research Council (Australia), Victorian Health Promotion Foundation, Australian Rotary Health, Colonial Foundation, Perpetual Trustees, Financial Markets Foundation for Children (Australia), Royal Children's Hospital Foundation, Murdoch Children's Research Institute, Australian Research Council.

Assessing alcohol guidelines in teenagers: results from a 10-year prospective study.

OBJECTIVE: To assess the value of drinking guidelines applied in adolescence for predicting alcohol-related outcomes in young adulthood. METHODS: We conducted an eight-wave, population-based cohort study of 696 males and 824 females in Victoria between 1992 and 2003. Adolescent drinking was assessed at five survey waves, in six month intervals, from mean age 15.4-17.4 years. We created three measures of adolescent alcohol use using categories from NHMRC drinking guidelines: risky/high-risk drinking in the short and long term (2001), and high-risk drinking (2007). Each measure was defined according to the number of waves at which drinking was reported at or above the designated level during adolescence: non-drinkers, zero waves (low-risk drinkers), one wave, and 2+ waves. Alcohol use disorders and alcohol-related sexual behaviours were assessed at mean age 24.1 years. RESULTS: Fourteen per cent of males and 17% of females were non-drinkers during adolescence. Using each NHMRC drinking guideline, the prevalence of each outcome for men increased with the number of waves at which drinking was reported above the low-risk level (p-values <0.007). The association was less clear for women. The prevalence of each outcome was lower among the nondrinkers compared to the low-risk drinkers for both men and women. CONCLUSIONS AND IMPLICATIONS: These findings support the emphasis in the NHMRC guidelines on abstaining from alcohol during the adolescent years. Any drinking, even at the low-risk level, may not be appropriate in adolescence. However, refinements that could better capture the risk of adolescent drinking in women would be useful.

Adolescent cannabis users at 24 years: trajectories to regular weekly use and dependence in young adulthood.

AIMS: To examine the association between cannabis use by 18 years and problematic cannabis use at 24 years, considering possible mediating and confounding factors. DESIGN: Ten-year representative prospective study with data from six time-points in adolescence (mean age 14.9-17.4 years) and two in young adulthood (mean age 20.7 and 24.1 years) SETTING: Victoria, Australia. PARTICIPANTS: Inception cohort of 1943 secondary school students (95.6% response rate), with 1520 (78% of adolescent participants) interviewed in the final wave. MEASUREMENTS: Participants reported frequency of cannabis use for the past 6 months at each time-point in adolescence (age 14-17 years). Cannabis exposure was defined as: maximum frequency of use (occasional, weekly, daily), number of waves of use (1 or 2; 3-6) and first wave of use (early use: first waves 1-3). Young adult (24 years) outcomes were: weekly+ cannabis use and DSM-IV cannabis dependence, referred to collectively as problematic use. FINDINGS: Of those interviewed at age 24 (wave 8), 34% had reported cannabis use in adolescence (waves 1-6), 12% at a level of weekly or more frequent use; 37% of these adolescent cannabis users were using at least weekly at wave 8, with 20% exhibiting dependence. Persistent adolescent cannabis and tobacco use as well as persistent mental health problems were associated strongly with problematic cannabis use at 24 years, after adjustment for potential confounding factors. CONCLUSIONS: Heavy, persistent and early-onset cannabis use were all strongly predictive of later cannabis problems. Even so, occasional use was not free of later problems. Where there was co-occurring tobacco use or persistent mental health problems, risks for later problem cannabis use was higher.