Drug prevention strategies

Transcription

1 Prevention Research Evaluation Report Number 2 September 2002 Drug prevention strategies A developmental settings approach by Associate Professor John W. Toumbourou, Centre for Adolescent Health Introduction The first report in this series identified patterns of adolescent drug use that lead to economic and social harms. Such patterns include regular tobacco use, alcohol abuse and alcohol dependence, frequent cannabis use, illicit drug use and poly drug use. In this second report we examine prevention strategies, paying particular attention to what is known of the factors that lead to harmful drug use. By reducing the developmental influences that lead to harmful drug use, prevention strategies reduce not only drug-related harm among young people, but also other health and social problems that share similar developmental determinants. A developmental pathways approach to prevention Australian prevention programs are placing a growing emphasis upon a developmental pathways approach. This approach, emphasised in Australian mental health (National Mental Health Strategy, 1999) and crime prevention strategies (National Crime Prevention, 1999), aims to direct evidencebased investment to modify the early developmental pathways that lead to later problems. The approach has emerged through the synthesis of a range of scientific endeavour, but draws in important ways on life-course development research, community epidemiology and preventive intervention trials (Coie et al., 1993; Kellam & Rebok, 1992). In common with the broad area known as prevention science, the developmental pathways approach seeks to prevent health and social problems by identifying and then reducing factors that lead individuals and groups to subsequently develop health or social problems. The approach is based on techniques developed to prevent health problems within the fields of public health and epidemiology (Institute of Medicine, 1994). Although an ultimate understanding of underlying causal processes is sought, in general this approach aims initially to understand the probability relationship between early indicators and subsequent problems. Risk and protective factors for harmful drug use Borrowing similar techniques to those that have been used to study risk and protective factors for heart disease, researchers have been studying over the past three decades risk and protective factors that lead to youth drug abuse. Risk factors for the development of harmful drug use can be defined as prospective (or long-term) predictors that increase the probability that an individual or group will eventually engage in harmful drug use (Hawkins, Catalano & Miller, 1992). Protective factors are those factors that mediate or moderate the influence of risk factors (Cowen & Work, 1988; Garmezy, 1985; Rutter, 1985; Werner, 1989).

2 What are the risk factors for harmful drug use? A number of literature reviews have examined the risk and protective factors influencing young people s drug use and harmful drug use (Hawkins, Catalano & Miller, 1992; Hawkins, Arthur & Catalano, 1995; Kandel et al., 1986; Loeber, Stouthamer-Loeber et al., 1991; Newcomb & Felix-Ortiz, 1992; Newcomb et al., 1987; Werner & Smith, 1992; White, Pandina & LaGrange, 1987). The review paper by Hawkins, Catalano & Miller (1992) was influential in organising what was known to that point of risk and protective factors for young people s drug abuse. Risk factors were organised according to their influence in different developmental settings, including communities, families, schools and peer groups, and within individuals. Community factors Community factors included legal and normative expectations for behaviour, availability of substances, extreme economic deprivation, transitions and mobility and high levels of neighbourhood disorganisation. In the family, family history of substance abuse, poor family management practices, family conflict, parental drug use and parental attitudes favourable towards drug use predicted substance use. School Within the socialisation unit of the school, early and persistent problem behaviour, academic failure and low commitment to school were found to predict substance use. Individual and peer factors Individual and peer factors included constitutional factors (e.g. sensation seeking and lack of impulse control, Rutter, 1987; Bry, McKeon & Pandina, 1982) alienation and rebelliousness, attitudes favourable towards drug use, association with anti-social peers, early initiation of substance use and other problem behaviours. What are the protective factors? The review by Hawkins and colleagues (1992) also organised what was known of protective factors, arguing that they fell into three basic categories (Rutter, 1987; Werner & Smith, 1992): individual characteristics (a positive social orientation, high intelligence and a resilient temperament) social bonding (warm, affective relationships and commitment to conventional lines of action) healthy beliefs and clear standards for behaviour. More recent literature reviews have examined risk and protective factors for harmful drug use by examining research completed over the past ten years (Toumbourou et al., 2000; Toumbourou et al., 2002). Findings tend to confirm many of the factors that were previously identified in the literature reviews relevant to the research completed up to the end of the 1980s (Hawkins, Catalano & Miller, 1992). Parental attitudes Parenting and family appeared to act in early adolescence Family attitudes and behaviour to predict frequent were important predictors, as alcohol use and were parental child-rearing alcohol abuse. practices. Parental substance use, parental substance use problems, family conflict and sexual abuse were identified as family-level predictors from early in a child's life. Parental attitudes appeared to act in early adolescence to predict frequent alcohol use and alcohol abuse. Low family attachment in early adolescence predicted poly drug use and frequent cannabis use. In some cohorts parental permissiveness in adolescence predicted illicit drug use. Family breakdown either early or late in a child's development predicted both alcohol and drug use problems. Community At the community level, low SES was an inconsistent predictor. High community mobility Page 2 of 10

3 in childhood or adolescence predicted poly drug use and illicit drug use. Peers Many peer-level factors were predictors in adolescence. Peer substance use and deviant peers in adoles-cence predicted both alcohol and illicit drug problems. Individual factors At the individual level, male gender was an inconsistent predictor. Early youth substance use in adolescence was a consistent predictor of later problems, as were conduct problems in late childhood or early adolescence. Attention Deficit Hyperactivity Disorder in childhood or adolescence has been widely studied and appears to be an inconsistent predictor of either frequent alcohol use, abuse or frequent cannabis use. Adolescent depressive symptoms show inconsistent prediction. Adolescent anxiety symptoms tend not to be direct predictors. Adventurousness as a child or novelty seeking/ sensation seeking in adolescence tend to be positive predictors across a range of harmful substance use behaviours. Interventions tackling each of these areas therefore appear to have relevance for prevention efforts. The available research provides some indication of the patterns of early substance use that are more likely to lead to later harm. In summary, the major implications of these findings are as follows. Early adolescent (age 12 14) cigarette smoking, alcohol use or poly drug use (use of a variety of licit and illicit substances) is a moderate to strong predictor of later problems with substance use. Early age use and more frequent use of a specific substance (e.g. alcohol) through adolescence generally increases the risk of problems with that substance later in life. Patterns of substance use in midadolescence (age 15 17) show a moderate to strong tendency to either escalate or remain stable in lateadolescence (age 18 24) and, so far as there is evidence, into early adulthood (age 25 30). Initiation to early adolescent substance use is influenced by risk and protective factors that can be identified in both childhood and adolescence. The severity of substance abuse problems appears to be associated with the extent of developmental problems. For young people with the most severe problems, pathways to substance abuse can often be traced to the earliest years of life. Williams et al. (2000), analysing data from the Australian Temperament Project, noted that temperament risk factors in infancy and early childhood emerged only when analyses focused on the 9 per cent of young people with the highest frequency of age 15 poly drug use (use of four or more substances). Research by Fergusson, Horwood & Lynskey (1994) examining the New Zealand Christchurch birth cohort demonstrated that when the focus narrowed on the 2.7 per cent of young people experiencing the most severe behaviour problems, early childhood development was characterised by maternal smoking and drinking during pregnancy, birth complications, problems in infant care (low breast feeding, low infant care, poor parenting) and social instability through childhood (family breakdown and parental changes). The family backgrounds of these children were characterised by high levels of social disadvantage (teenage parents, low education, low income, sole parents) and social disconnection (low rates of church attendance, parent mobility). Bearing the above generalisation in mind, follow-up studies have not consistently identified low SES to be a risk factor for harmful substance use. The cumulative number of risk factors The current state of the science of prevention suggests that risk factors influence the course of development through their cumulative impact across time. This means that there is no single risk factor that lies at the heart of developmental problems. Rather, these problems can be regarded to have complex causes or multiple there is no single risk factor that lies at the heart of developmental problems Page 3 of 10

4 determination. The more risk factors that persist over longer periods of time, the greater the subsequent developmental impact (Bry, McKeon & Pandina, 1982; Newcomb & Felix- Ortiz, 1992). From one view, the cumulative effect of risk factors operates somewhat like a snowball. According to this view, risk-factor exposure early in life can impair the subsequent course of development and lead to a snowball effect, with subsequent risk factors tending to adhere and accumulate as a consequence of the earlier problems (Mitchell et al,, 2001). So, for example, mothers tobacco smoking may impede foetal and early childhood development, resulting in cognitive deficits that then lead to poor school adjustment. Poor school adjustment and school behaviour problems may lead on to social aggregation with other poor school-achieving young people. From this perspective, the solution is to check the avalanche of risk by intervening at the top of the mountain, the earliest point in the course of development. From a slightly different perspective, the cumulative effect of risk is more analogous to a snowstorm. According to this view, a child can withstand extreme weather for a brief period, but over time the chances of illness through exposure increase. For example, a healthy child may withstand drug use in the peer group and community for a period, but over time, if this behaviour is common, the chances of the child becoming involved in drug use increase. Having parents who are unavailable and bad experiences with teachers may increase the chances of the child becoming interested in drug use. The protective benefits of positive relationships with adults, observed even for children with damaged developmental pathways, are again suggestive of the potential to protect health in bad environments by providing protection (analagous to providing shelter in a stormy environment). From this perspective, solutions lie in improving social environments (reducing risk factors) through the course of development (Catalano & solutions lie in improving social environments (reducing risk factors) through the course of development Hawkins, 1996), strengthening the child s capacity to survive risky environments and enhancing protective factors to reduce the impact of risk. In attempting to explore the development of behaviour, an understanding of the sequencing of risk processes across the life span becomes important. At one point in development, a risk factor (such as early age alcohol use) will be studied as a predictor of subsequent behaviour (e.g. cannabis use). However, at an earlier stage in development the same factor may be seen as an outcome to be predicted by prior risk factors (e.g. childhood behavioural problems). What are some criticisms that might be levelled against the developmental pathways approach to prevention? The approach makes extensive use of data from the United States and therefore there are questions regarding the relevance to the Australian context. The approach is heavily weighted to individual-level data, and perhaps does not take adequate account of broader social and community determinants. The approach provides overall estimates of risk, but it is not yet known whether these apply to specific sub-populations such as indigenous children. Some of these issues are explored in the discussion that follows. Are risk and protective factors identified in overseas research relevant in Australia? There are now many studies that have demonstrated a long-term relationship between earlier developmental experiences and subsequent involvement in harmful drug use. The fact that much of this research has been conducted in the United States has led to questions regarding the applicability of this research in the Australian context. A number of Australian studies have increased the confidence that risk and protective factors for harmful drug use are similar in Australia to those identified in the international research literature. Page 4 of 10

5 The Australian experience The Australian Temperament Project (ATP) is an important follow-up research study that was initiated when 2443 infants, representative of the Victorian population, were recruited in 1983 when the children were 4 8 months old. Since that time, data collection has been conducted about every two years with parents, Maternal and Child Health nurses, teachers and from late childhood the children themselves. The study has provided information on domains including behaviour problems, temperament, mother child relationship, health, school achievement and adjustment, social skills, peer relationships, parenting practices, stressful life events, sociodemographic indices, depressive symptoms and drug use (Prior et al., 2000). Williams et al. (2000) presented an analysis of data from the ATP to identify long-term predictors of poly drug use or illicit drug use at age 15. Predictors were identified to include early temperament characteristics (less regular eating, and sleeping and more restlessness in infancy, less shyness and caution toward strangers in childhood) and teacher-reported aggression in early child-hood. In late childhood and early adolescence, predictors included depressive symptoms, peer relations, mother s drinking habits, low community participation, hyperactivity, delinquent behaviour, and low emotional control. The conclusion in that report was that many of the factors that had predicted youth drug use in the overseas research also appeared to be predictors in Australian follow-up research. In a separate Victorian study, a research instrument developed to measure risk and protective factors within the United States youth population was successfully adapted for use in the Australian context (Bond et al., 2000). The survey instrument used in this study measured twenty-five risk factors and ten protective factors that had been identified as longitudinal predictors in previous research. The research in Victoria involved adapting the survey instrument and then using it to survey a representative sample of 9000 high school students. Findings from the survey confirmed a similar psychometric structure in the Australian youth population, with similar relationships applying to students responses regarding their behaviour and experience. Although there were some differences noted, with higher levels of alcohol use among Australian students, the general relationship between risk and protective factors and youth drug use was remarkably similar in Australia when compared with United States samples (Bond et al., 2000). The implication of this study was that the factors influencing youth drug use in Australia were similar to those operating in the United States, and hence prevention studies run successfully in the United States should be considered for their potential application in the Australian setting. An important implication of the research examining risk and protective factors is that the cumulative number of factors influencing the development of harmful drug use among young people also predicts other youth problems including delinquency, homelessness, mental health problems and sexual risk taking (Bond et al., 2000). These findings have led to the view that many prevention strategies that have relevance in preventing harmful drug use among young people will also be relevant to preventing problems in other areas. These conclusions have led to an increased attraction to doing prevention work as a common activity across jurisdictions, incorporating money and resources from the drug and alcohol sector with resources from crime prevention, mental health promotion, welfare and health. The settings approach to drug prevention Knowledge of the factors that influence the development of harmful youth drug use has not only come from follow-up research studies, but also from a range of intervention research (Toumbourou et al., 2000). Given that factors within the community, families, schools and peer groups, and within individual attitudes and behaviour are important determinants of harmful youth drug use, a wide range of intervention strategies appear to be relevant. Page 5 of 10

6 Although terminology tends to be inconsistently used across the prevention literature, in the present document interventions is defined as the core processes through which prevention activities are conceived to achieve behaviour change. Programs can be defined as vehicles for delivering and sequencing interventions over time, and strategies can thus be defined as the broad umbrella category describing the coherent organisation of programs within settings. Table 1 (see page 7) provides definitions for a range of strategies that were identified in a recent review of the prevention literature. The organisation of strategies in the table emphasises the grouping of prevention activities according to the workforce jurisdictions required to engage in coordinated activity in order to deliver interventions in the settings in which children grow up and are exposed to developmental influences. Table 2 (see page 8) provides a summary strategies that have evidence for their effectiveness and dissemination in modifying developmental trajectories leading to harmful youth drug use. Strategies with evidence for outcomes include family intervention, parent education, school drug education, school organisation and behaviour management, restrictions on the sale of tobacco and alcohol and community mobilisation. The Toumbourou et al. (2002) review noted that, while family, peer and individual factors have been the most common predictors of harmful substance use, school-based programs have been amongst the most commonly evaluated early intervention strategies. Although existing research studies have established that discrete interventions can be effective, there appear to be important advantages for early intervention strategies to be creatively integrated and coordinated across time. Toumbourou et al. (2000) noted in their review that programs incorporating more than one health promotion strategy appeared to be more consistently effective. For example, social marketing combined with school-based health education appeared to be more effective than either strategy alone (Flynn et al., 1997). Programs that target more than one risk factor (e.g. parental bonding and peer interaction) may increase the likelihood of an effect, and hence result in more consistent impacts (e.g. Eddy, Reid & Fetrow, 2000). The review of school-based drug education revealed that one-off sessions or intervention for only one school year were less successful than interventions maintained across multiple years. These considerations led to the conclusion that investment in prevention activities should aim to maintain a coordinated set of activities through childhood and adolescence. Activities should address the developmental stage of youth and build on earlier components. Although most people agree with the principle of early investment to prevent later problems, there are a number of important barriers that must be overcome in order to establish an effective prevention framework (Arthur & Blitz, 2000). A major initial problem is the long-term nature of prevention activities. It is sometimes said that the long-term focus of prevention does not fit the short-term requirement for political priorities. A second problem facing efforts to establish prevention programs is that public opinion often requires immediate responses to immediate problems. Where community awareness is lacking it may be difficult to link investment in childhood and adolescence with the down-stream social problems that prevention investment aims to reduce. A third problem facing efforts to improve preventative services is that many of the self-evident methods of encouraging prevention are ineffective. Successful prevention requires that evidence-based strategies are appropriately selected and then applied in a manner that retains the effective elements. The evidence is consistent across outcomes that weakly implemented interventions show inconsistent or null effects. Strategies with evidence for outcomes include family intervention, parent education, school drug education, school organisation and behaviour management, restrictions on the sale of tobacco and alcohol, and community mobilisation. Page 6 of 10

7 Table 1: Definition of prevention strategies (based on Toumbourou et al., 2000) Prevention strategies (delivery settings) Definitions Family setting Family services Family Intervention Parent Education School setting School services School Drug Education (curricula) School Organisation and Behaviour Management One or more parents, children and other family members receiving information and/or a course of instruction together, aimed at encouraging healthy family development. Delivery strategies include programs to prevent pregnancy in young and vulnerable mothers, early family home visitation and both targeted and universal interventions One or more parents receiving information and/or a course of instruction aimed at encouraging healthy family development. Delivery strategies include targeted, universal and combined interventions. Delivery of a structured social-health, drug education curriculum within the school, usually by classroom teachers, but in some cases by visiting outside professionals. Include 1) strategies to better prepare children for the transitions to primary and secondary schools, 2) programs aimed at encouraging positive interpersonal relationships at school, 3) policies and procedures to ensure effective discipline and 4) strategies to maximise learning opportunities Peer settings Typically coordinated by schools, non-government organisations or local government Peer Intervention and Peer Education Youth peers of common identity provide support or deliver a health message. Youth Sport and Recreation Programs Provision or utilisation of recreational opportunities outside the school setting to promote the positive development of children and young people. Mentorship Strategies to develop pro-social relationships between young people and functioning adults within the community Community setting Locally coordinated programs Community Based Drug Education Adolescent drug education curricula or information delivered in a community setting other than in schools Preventative Case-Management Coordinated delivery of more intensive services tailored to meet a range of developmental needs. Generally targeted to children and adolescents with multiple risk factors. Community Mobilisation Campaigns to initiate or strengthen an explicit strategy of coordinated community action and aiming to advance health within targeted adolescent populations Community setting Regionally or state-coordinated programs Health Service Re-orientation Includes re-orientation of existing health services to modify developmental risk and protective factors and enhancement of service access for young people Employment and Training Includes provision of pre-employment assistance, employment experience, training or intervention in a post-school training setting, with the aim of advancing adolescent health Law, regulation, policing and enforcement Modification to, and enforcement of, legislation or regulations, policing strategies and procedures for dealing with offenders, aimed at preventing initiation or escalation of youth behaviour problems Social Marketing Use of the mass media to promote a health message relevant to young people s health Page 7 of 10

8 Table 2: Summary of evidence base for strategies targeting the prevention of harmful drug use and other adolescent health problems (from Toumbourou et al, 2002) Health promotion strategies Harmful drug use Family Intervention Preventing pregnancy in young and vulnerable women Family home visiting Targeted family intervention Universal family intervention Parent Education Targeted parent education Universal parent education Integrating multi-level parent education within schools 1/1 School Drug Education School Organisation and Behaviour Management Peer Intervention and Peer Education Warning 2/4 negative results Youth Sport and Recreation Mentorship 1/1 Community Based Drug Education Warning 1/2 negative results Preventative Case Management 1/1 Health Service Re-orientation 3/3 Employment and Training Law, Regulation, Policing and Enforcement Restrictions on the marketing of alcohol, tobacco and other licit drugs Restrictions on the manufacture, distribution and sale of tobacco and alcohol Restrictions on the manufacture, distribution and sale of illicit drugs Procedures for diverting offenders into early intervention services Community Mobilisation Social Marketing 1/1 Limited investigation Evidence is contra-indicative Warrants further research Evidence for implementation. p/n Proportion of studies with positive impacts. Evidence for outcome effectiveness Evidence for effective dissemination A further issue confronting prevention efforts is that they may not easily fit within the brief of existing service organisations in their requirement for long-term work across multiple developmental settings (e.g. linking schools, communities and families). As one response to these problems, efforts are being made to raise community awareness of the requirements for community prevention. Substantial effort is also being made to increase local capacity to be involved in the planning and delivery of preventative services. Page 8 of 10

9 An important issue for prevention efforts is ensuring evaluation funding and expertise. Evaluation of prevention efforts may involve many levels, from community organisation change through to drug use behaviour change. Funding to enable both prevention process evaluation, social environment improvement and longer-term evaluation of behaviour change are each important components in ensuring the overall success of prevention investments (Arthur & Blitz, 2000). Although prevention is sometimes considered to be necessary only for young people with a high number of risk factors, there appears to be potential to alter the trajectories of disadvantaged youth through universal interventions aimed at improving social environments for the whole population. Young people with multiple risk factors demonstrate better outcomes where negative social interactions are reduced among school peers (Eddy, Reid & Fetrow, 2000; Toumbourou & Gregg, in press), where relationships are enhanced with school teachers (Glover et al., 1998) and other adults (Tierney, Grossman & Resch, 1995) and where broader community changes reduce access to substances (Forster et al., 1998) and promote positive community environments (Chou et al., 1998). References Arthur, MW & Blitz, C 2000 'Bridging the gap between science and practice in drug abuse prevention through needs assessment and strategic community planning', Journal of Community Psychology, 28:3, pp Bond, L, Thomas, L, Toumbourou, J, Patton, GC & Catalano, R 2000 Improving the lives of young Victorians in our community: A survey of risk and protective factors, Centre for Adolescent Health Report prepared for Community Care Division, Department of Human Services Bry, BH, McKeon, P & Pandina, RJ 1982 'Extent of drug use as a function of number of risk factors', Journal of Abnormal Psychology, 91:4, pp Catalano, RF, & Hawkins, JD 1996 'The social development model: A theory of antisocial behavior', in JD Hawkins (ed.), Delinquency and crime: Current theories, New York: Cambridge, pp Chou, C, Montgomery, S, Pentz, MA, Rohrbach, LA, Johnson, CA, Flay, BR & MacKinnon, DP 1998 'Effects of a community-based prevention program on There are roles in such an endeavour for both state and regional services. State-wide dissemination may be critical for strategies such as legislative change and social marketing. Regional funding may be most appropriate to increase expertise in programs with evidence for impacts on regionally prioritised risk factors, protective factors and youth health and behavioural problems. Conclusion In this report, risk and protective factors for harmful drug use were reviewed. The existence of these factors across the major domains of development (communities, schools, families, peer groups) emphasises the requirement to direct prevention investment in many areas. There has been considerable progress in Australia in establishing a basis for prevention in both the workforce and also within broader public opinion. Evaluation expertise remains an important gap. In the next of the current series of reports, prevention evaluations will be examined relevant to specific developmental settings, including schools, families and communities. decreasing drug use in high-risk adolescents', American Journal of Public Health, 88:6, pp Coie, JD, Watt, NF, West SG, Hawkins JD, Asarnow, JR, Markman, HJ, Ramey, SL, Shure, MB & Long, B 1993 'The science of prevention: A conceptual framework and some directions for a national research program', American Psychologist, 48: 10, pp Cowen, E & Work, W 1988 'Resilient children, psychological wellness, and primary prevention', American Journal of Community Psychology, 16, pp Eddy, JM, Reid, JB & Fetrow, RA 2000 'An elementary school-based prevention program targeting modifiable antecedents of youth delinquency and violence: Linking the interests of families and teachers (LIFT)', Journal of Emotional and Behavioural Disorders, 8, pp Fergusson, DM, Horwood, LJ & Lynskey, M 1994 'The childhoods of multiple problem adolescents: A 15-year longitudinal study', Journal of Child Psychology and Psychiatry, 35, pp Flynn, BS, Worden, JK, Secker-Walker, RH, Pirie, PL, Badger, GJ & Carpenter, JH 1997 'Long-term responses Page 9 of 10

10 of higher and lower risk youths to smoking prevention interventions', Preventive Medicine, 26, pp Forster, JL, Murray, DM, Wolfson, M, Blaine, TM, Wagenaar, AC & Hennrikus, DJ 1998 'The effects of community policies to reduce youth access to tobacco', American Journal of Public Health, 88, pp Garmezy, N 1985 'Stress-resistant children: The search for protective factors', in JE Stevenson (ed.), Recent research in developmental psychopathology (pp ), Journal of Child Psychology and Psychiatry, supp. 4 Glover, S, Burns, J, Butler, H & Patton, G.P 1998 'Social environments and the emotional well-being of young people', Family Matters, 49, pp Hawkins, JD, Arthur, MW & Catalano, RF 1995 'Preventing substance abuse', in D Farrington & M Tonry (eds) Crime and justice: A review of research, 18, Crime Prevention, Chicago: University of Chicago Press Hawkins, JD, Catalano, RF & Miller, JY 1992 'Risk and protective factors for alcohol and other drug problems in adolescence and early adulthood: Implications for substance abuse prevention', Psychological Bulletin, 112, pp Institute of Medicine 1994 Reducing risks for mental disorders: Frontiers for preventive intervention research, Washington, DC: National Academy Press Kandel, DB, Simcha-Fagan, O & Davies, M 1986 'Risk factors for delinquency and illicit drug use from adolescence to young adulthood', Journal of Drug Issues, 16, pp Kellam, SG & Rebok, GW 1992 'Building developmental and etiological theory through epidemiologically based preventive intervention trials', in J McCord & RE Tremblay (eds) Preventing antisocial behavior: Interventions from birth through adolescence, New York: Guilford, pp ) Loeber, R, Stouthamer-Loeber, MS, Van Kammen, W & Farrington, DP 1991 'Initiation, escalation, and desistance in juvenile offending and their correlates', Journal of Criminal Law and Criminology, 82, pp Mitchell, P, Spooner, C, Copeland, J, Vimpani, G, Toumbourou, JW, Howard, J & Sanson, A 2001 The role of families in the development, identification, prevention and treatment of illicit drug problems, Canberra: National Health and Medical Research Council National Crime Prevention, 1999 Pathways to prevention: Developmental and early intervention approaches to crime in Australia, Canberra: Commonwealth Attorney General s Department National Mental Health Strategy 1999 Promotion, prevention and early intervention for mental health', Canberra: Department of Health and Aged Care Newcomb, MD & Felix-Ortiz, M 1992 'Multiple protective and risk factors for drug use and abuse: Cross-sectional and prospective findings', Journal of Personality & Social Psychology, 63, pp Newcomb, MD, Maddahian, E, Skager, R & Bentler, PM 1987 'Substance abuse and psychosocial risk factors among teenagers: Associations with sex, age, ethnicity and type of school', American Journal of Drug and Alcohol Abuse, 13, pp Prior, M, Sanson, A, Smart, D & Oberklaid, F 2000 Pathways from infancy to adolescence: Australian Temperament Project Melbourne, Australia: Australian Institute of Family Studies Rutter, M 1985 'Resilience in the face of adversity: Protective factors and resistance to psychiatric disorder', British Journal of Psychiatry, 147, pp Rutter, M 1987 'Temperament, personality, and personality disorder', British Journal of Psychiatry, 150, pp Tierney, JP, Grossman, JB & Resch, NL 1995 Making a difference. An impact study of Big Brothers/Big Sisters, Philadelphia, PA: Public/Private Ventures Toumbourou, JW & Gregg, ME in press 'Impact of an empowerment-based parent education program on the reduction of youth suicide risk factors', Journal of Adolescent Health Toumbourou, J, Patton, G, Sawyer, S, Olsson, C, Web- Pullmann, J, Catalano, R & Godfrey, C 2000 Evidencebased interventions for promoting adolescent health, Melbourne: Centre for Adolescent Health Toumbourou, JW, Snow, P, Sanci, L & Williams J 2002 'Literature review of early intervention for young people with drug problems', prepared by the Centre for Adolescent Health for the Victorian Department of Human Services Werner, EE 1989 'High-risk children in young adulthood: A longitudinal study from birth to 32 years', American Journal of Orthopsychiatry, 59, pp Werner, EE & Smith, RS 1992 Overcoming the odds: High risk children from birth to adulthood, Ithaca, NY: Cornell University Press White, HR, Pandina, RJ & LaGrange, RL 1987 'Longitudinal predictors of serious substance use and delinquency', Criminology, 25, pp Williams, B, Sanson, A, Toumbourou, J & Smart, D 2000 'Patterns and predictors of teenagers use of licit and illicit substances in the Australian Temperament Project cohort', report prepared for the Ross Trust, Parkville, Victoria: Department of Behavioural Science, The University of Melbourne This report was prepared for the DrugInfo Clearinghouse by the Centre for Adolescent Health, Melbourne Page 10 of 10