Development and evaluation of a risk algorithm predicting alcohol dependence after early onset of regular alcohol use.

AIMS: Likelihood of alcohol dependence (AD) is increased among people who transition to greater levels of alcohol involvement at a younger age. Indicated interventions delivered early may be effective in reducing risk, but could be costly. One way to increase cost-effectiveness would be to develop a prediction model that targeted interventions to the subset of youth with early alcohol use who are at highest risk of subsequent AD. DESIGN: A prediction model was developed for DSM-IV AD onset by age 25 years using an ensemble machine-learning algorithm known as 'Super Learner'. Shapley additive explanations (SHAP) assessed variable importance. SETTING AND PARTICIPANTS: Respondents reporting early onset of regular alcohol use (i.e. by 17 years of age) who were aged 25 years or older at interview from 14 representative community surveys conducted in 13 countries as part of WHO's World Mental Health Surveys. MEASUREMENTS: The primary outcome to be predicted was onset of life-time DSM-IV AD by age 25 as measured using the Composite International Diagnostic Interview, a fully structured diagnostic interview. FINDINGS: AD prevalence by age 25 was 5.1% among the 10 687 individuals who reported drinking alcohol regularly by age 17. The prediction model achieved an external area under the curve [0.78; 95% confidence interval (CI) = 0.74-0.81] higher than any individual candidate risk model (0.73-0.77) and an area under the precision-recall curve of 0.22. Overall calibration was good [integrated calibration index (ICI) = 1.05%]; however, miscalibration was observed at the extreme ends of the distribution of predicted probabilities. Interventions provided to the 20% of people with highest risk would identify 49% of AD cases and require treating four people without AD to reach one with AD. Important predictors of increased risk included younger onset of alcohol use, males, higher cohort alcohol use and more mental disorders. CONCLUSIONS: A risk algorithm can be created using data collected at the onset of regular alcohol use to target youth at highest risk of alcohol dependence by early adulthood. Important considerations remain for advancing the development and practical implementation of such models.

The associations between traumatic experiences and subsequent onset of a substance use disorder: Findings from the World Health Organization World Mental Health surveys.

AIM: Exposure to traumatic events (TEs) is associated with substance use disorders (SUDs). However, most studies focus on a single TE, and are limited to single countries, rather than across countries with variation in economic, social and cultural characteristics. We used cross-national data to examine associations of diverse TEs with SUD onset, and variation in associations over time. METHODS: Data come from World Mental Health surveys across 22 countries. Adults (n = 65,165) retrospectively reported exposure to 29 TEs in six categories: "exposure to organised violence"; "participation in organised violence"; "interpersonal violence"; "sexual-relationship violence"; "other life-threatening events"; and those involving loved ones ("network traumas"). Discrete-time survival analyses were used to examine associations with subsequent first SUD onset. RESULTS: Most (71.0%) reported experiencing at least one TE, with network traumas (38.8%) most common and exposure to organised violence (9.5%) least. One in five (20.3%) had been exposed to sexual-relationship violence and 26.6% to interpersonal violence. Among the TE exposed, lifetime SUD prevalence was 14.5% compared to 5.1% with no trauma exposure. Most TE categories (except organised violence) were associated with increased odds of SUD. Increased odds of SUD were also found following interpersonal violence exposure across all age ranges (ORs from 1.56 to 1.78), and sexual-relationship violence exposure during adulthood (ORs from 1.33 to 1.44), with associations persisting even after >11 years. CONCLUSION: Sexual and interpersonal violence have the most consistent associations with progression to SUD; increased risk remains for many years post-exposure. These need to be considered when working with people exposed to such traumas.

Demographic and mental health assessments in the adolescent brain and cognitive development study: Updates and age-related trajectories.

The Adolescent Brain Cognitive Development (ABCD) Study of 11,880 youth incorporates a comprehensive range of measures assessing predictors and outcomes related to mental health across childhood and adolescence in participating youth, as well as information about family mental health history. We have previously described the logic and content of the mental health assessment battery at Baseline and 1-year follow-up. Here, we describe changes to that battery and issues and clarifications that have emerged, as well as additions to the mental health battery at the 2-, 3-, 4-, and 5-year follow-ups. We capitalize on the recent release of longitudinal data for caregiver and youth report of mental health data to evaluate trajectories of dimensions of psychopathology as a function of demographic factors. For both caregiver and self-reported mental health symptoms, males showed age-related decreases in internalizing and externalizing symptoms, while females showed an increase in internalizing symptoms with age. Multiple indicators of socioeconomic status (caregiver education, family income, financial adversity, neighborhood poverty) accounted for unique variance in both caregiver and youth-reported externalizing and internalizing symptoms. These data highlight the importance of examining developmental trajectories of mental health as a function of key factors such as sex and socioeconomic environment.

Optimizing scalable, technology-supported behavioral interventions to prevent opioid misuse among adolescents and young adults in the emergency department: A randomized controlled trial protocol.

Preventing opioid misuse and opioid use disorder is critical among at-risk adolescents and young adults (AYAs). An Emergency Department (ED) visit provides an opportunity for delivering interventions during a rapidly changing opioid landscape. This paper describes pilot data and the protocol for a 2 × 2 factorial randomized controlled trial testing efficacy of early interventions to reduce escalation of opioid (prescription or illicit) misuse among at-risk AYAs. Interventions are delivered using technology by health coaches. AYAs ages 16-30 in the ED screening positive for prescription opioid use (+ ≥ 1 risk factor) or opioid misuse will be stratified by risk severity, sex, and age group. Participants will be randomly assigned to a condition at intake, either a live video health coach-delivered single session or a control condition of an enhanced usual care (EUC) community resource brochure. They are also randomly assigned to one of two post-intake conditions: health coach-delivered portal-like messaging via web portal over 30 days or EUC delivered at 30 days post-intake. Thus, the trial has four groups: health coach-delivered session+portal, health coach-delivered session+EUC, EUC + portal, and EUC + EUC. Outcomes will be measured at 3-, 6-, and 12-months. The primary outcome is opioid misuse based on a modified Alcohol Smoking and Substance Involvement Screening Test. Secondary outcomes include other opioid outcomes (e.g., days of opioid misuse, overdose risk behaviors), other substance misuse and consequences, and impaired driving. This study is innovative by testing the efficacy of feasible and scalable technology-enabled interventions to reduce and prevent opioid misuse and opioid use disorder. Trial Registration:ClinicalTrials.gov University of Michigan HUM00177625 NCT Registration: NCT04550715.

The epidemiology of alcohol use disorders cross-nationally: Findings from the World Mental Health Surveys.

BACKGROUND: Prevalences of Alcohol Use Disorders (AUDs) and Mental Health Disorders (MHDs) in many individual countries have been reported but there are few cross-national studies. The WHO World Mental Health (WMH) Survey Initiative standardizes methodological factors facilitating comparison of the prevalences and associated factors of AUDs in a large number of countries to identify differences and commonalities. METHODS: Lifetime and 12-month prevalence estimates of DSM-IV AUDs, MHDs, and associations were assessed in the 29 WMH surveys using the WHO CIDI 3.0. RESULTS: Prevalence estimates of alcohol use and AUD across countries and WHO regions varied widely. Mean lifetime prevalence of alcohol use in all countries combined was 80%, ranging from 3.8% to 97.1%. Combined average population lifetime and 12-month prevalence of AUDs were 8.6% and 2.2% respectively and 10.7% and 4.4% among non-abstainers. Of individuals with a lifetime AUD, 43.9% had at least one lifetime MHD and 17.9% of respondents with a lifetime MHD had a lifetime AUD. For most comorbidity combinations, the MHD preceded the onset of the AUD. AUD prevalence was much higher for men than women. 15% of all lifetime AUD cases developed before age 18. Higher household income and being older at time of interview, married, and more educated, were associated with a lower risk for lifetime AUD and AUD persistence. CONCLUSIONS: Prevalence of alcohol use and AUD is high overall, with large variation worldwide. The WMH surveys corroborate the wide geographic consistency of a number of well-documented clinical and epidemiological findings and patterns.

The epidemiology of drug use disorders cross-nationally: Findings from the WHO's World Mental Health Surveys.

BACKGROUND: Illicit drug use and associated disease burden are estimated to have increased over the past few decades, but large gaps remain in our knowledge of the extent of use of these drugs, and especially the extent of problem or dependent use, hampering confident cross-national comparisons. The World Mental Health (WMH) Surveys Initiative involves a standardised method for assessing mental and substance use disorders via structured diagnostic interviews in representative community samples of adults. We conducted cross-national comparisons of the prevalence and correlates of drug use disorders (DUDs) in countries of varied economic, social and cultural nature. METHODS AND FINDINGS: DSM-IV DUDs were assessed in 27 WMH surveys in 25 countries. Across surveys, the prevalence of lifetime DUD was 3.5%, 0.7% in the past year. Lifetime DUD prevalence increased with country income: 0.9% in low/lower-middle income countries, 2.5% in upper-middle income countries, 4.8% in high-income countries. Significant differences in 12-month prevalence of DUDs were found across country in income groups in the entire cohort, but not when limited to users. DUDs were more common among men than women and younger than older respondents. Among those with a DUD and at least one other mental disorder, onset of the DUD was usually preceded by the 'other' mental disorder. CONCLUSIONS: Substantial cross-national differences in DUD prevalence were found, reflecting myriad social, environmental, legal and other influences. Nonetheless, patterns of course and correlates of DUDs were strikingly consistent. These findings provide foundational data on country-level comparisons of DUDs.

Association of Cohort and Individual Substance Use With Risk of Transitioning to Drug Use, Drug Use Disorder, and Remission From Disorder: Findings From the World Mental Health Surveys.

Importance: Limited empirical research has examined the extent to which cohort-level prevalence of substance use is associated with the onset of drug use and transitioning into greater involvement with drug use. Objective: To use cross-national data to examine time-space variation in cohort-level drug use to assess its associations with onset and transitions across stages of drug use, abuse, dependence, and remission. Design, Setting, and Participants: The World Health Organization World Mental Health Surveys carried out cross-sectional general population surveys in 25 countries using a consistent research protocol and assessment instrument. Adults from representative household samples were interviewed face-to-face in the community in relation to drug use disorders. The surveys were conducted between 2001 and 2015. Data analysis was performed from July 2017 to July 2018. Main Outcomes and Measures: Data on timing of onset of lifetime drug use, DSM-IV drug use disorders, and remission from these disorders was assessed using the Composite International Diagnostic Interview. Associations of cohort-level alcohol prevalence and drug use prevalence were examined as factors associated with these transitions. Results: Among the 90 027 respondents (48.1% [SE, 0.2%] men; mean [SE] age, 42.1 [0.1] years), 1 in 4 (24.8% [SE, 0.2%]) reported either illicit drug use or extramedical use of prescription drugs at some point in their lifetime, but with substantial time-space variation in this prevalence. Among users, 9.1% (SE, 0.2%) met lifetime criteria for abuse, and 5.0% (SE, 0.2%) met criteria for dependence. Individuals who used 2 or more drugs had an increased risk of both abuse (odds ratio, 5.17 [95% CI, 4.66-5.73]; P < .001) and dependence (odds ratio, 5.99 [95% CI, 5.02-7.16]; P < .001) and reduced probability of remission from abuse (odds ratio, 0.86 [95% CI, 0.76-0.98]; P = .02). Birth cohort prevalence of drug use was also significantly associated with both initiation and illicit drug use transitions; for example, after controlling for individuals' experience of substance use and demographics, for each additional 10% of an individual's cohort using alcohol, a person's odds of initiating drug use increased by 28% (odds ratio, 1.28 [95% CI, 1.26-1.31]). Each 10% increase in a cohort's use of drug increased individual risk by 12% (1.12 [95% CI, 1.11-1.14]). Conclusions and Relevance: Birth cohort substance use is associated with drug use involvement beyond the outcomes of individual histories of alcohol and other drug use. This has important implications for understanding pathways into and out of problematic drug use.

Cross-national patterns of substance use disorder treatment and associations with mental disorder comorbidity in the WHO World Mental Health Surveys.

AIMS: To examine cross-national patterns of 12-month substance use disorder (SUD) treatment and minimally adequate treatment (MAT), and associations with mental disorder comorbidity. DESIGN: Cross-sectional, representative household surveys. SETTING: Twenty-seven surveys from 25 countries of the WHO World Mental Health Survey Initiative. PARTICIPANTS: A total of 2446 people with past-year DSM-IV SUD diagnoses (alcohol or illicit drug abuse and dependence). MEASUREMENTS: Outcomes were SUD treatment, defined as having either received professional treatment or attended a self-help group for substance-related problems in the past 12 months, and MAT, defined as having either four or more SUD treatment visits to a health-care professional, six or more visits to a non-health-care professional or being in ongoing treatment at the time of interview. Covariates were mental disorder comorbidity and several socio-economic characteristics. Pooled estimates reflect country sample sizes rather than population sizes. FINDINGS: Of respondents with past-year SUD, 11.0% [standard error (SE) = 0.8] received past 12-month SUD treatment. SUD treatment was more common among people with comorbid mental disorders than with pure SUDs (18.1%, SE = 1.6 versus 6.8%, SE = 0.7), as was MAT (84.0%, SE = 2.5 versus 68.3%, SE = 3.8) and treatment by health-care professionals (88.9%, SE = 1.9 versus 78.8%, SE = 3.0) among treated SUD cases. Adjusting for socio-economic characteristics, mental disorder comorbidity doubled the odds of SUD treatment [odds ratio (OR) = 2.34; 95% confidence interval (CI) = 1.71-3.20], MAT among SUD cases (OR = 2.75; 95% CI = 1.90-3.97) and MAT among treated cases (OR = 2.48; 95% CI = 1.23-5.02). Patterns were similar within country income groups, although the proportions receiving SUD treatment and MAT were higher in high- than low-/middle-income countries. CONCLUSIONS: Few people with past-year substance use disorders receive adequate 12-month substance use disorder treatment, even when comorbid with a mental disorder. This is largely due to the low proportion of people receiving any substance use disorder treatment, as the proportion of patients whose treatment is at least minimally adequate is high.

Concordance between the diagnostic guidelines for alcohol and cannabis use disorders in the draft ICD-11 and other classification systems: analysis of data from the WHO's World Mental Health Surveys.

BACKGROUND AND AIMS: The World Health Organization's (WHO's) proposed International Classification of Diseases, 11th edition (ICD-11) includes several major revisions to substance use disorder (SUD) diagnoses. It is essential to ensure the consistency of within-subject diagnostic findings throughout countries, languages and cultures. To date, agreement analyses between different SUD diagnostic systems have largely been based in high-income countries and clinical samples rather than general population samples. We aimed to evaluate the prevalence of, and concordance between diagnoses using the ICD-11, The WHO's ICD 10th edition (ICD-10) and the Diagnostic and Statistical Manual of Mental Disorders, 4th and 5th editions (DSM-IV, DSM-5); the prevalence of disaggregated ICD-10 and ICD-11 symptoms; and variation in clinical features across diagnostic groups. DESIGN: Cross-sectional household surveys. SETTING: Representative surveys of the general population in 10 countries (Argentina, Australia, Brazil, Colombia, Iraq, Northern Ireland, Poland, Portugal, Romania and Spain) of the World Mental Health Survey Initiative. PARTICIPANTS: Questions about SUDs were asked of 12 182 regular alcohol users and 1788 cannabis users. MEASUREMENTS: Each survey used the World Mental Health Survey Initiative version of the WHO Composite International Diagnostic Interview version 3.0 (WMH-CIDI). FINDINGS: Among regular alcohol users, prevalence (95% confidence interval) of life-time ICD-11 alcohol harmful use and dependence were 21.6% (20.5-22.6%) and 7.0% (6.4-7.7%), respectively. Among cannabis users, 9.3% (7.4-11.1%) met criteria for ICD-11 harmful use and 3.2% (2.3-4.0%) for dependence. For both substances, all comparisons of ICD-11 with ICD-10 and DSM-IV showed excellent concordance (all κ ≥ 0.9). Concordance between ICD-11 and DSM-5 ranged from good (for SUD and comparisons of dependence and severe SUD) to poor (for comparisons of harmful use and mild SUD). Very low endorsement rates were observed for new ICD-11 feature for harmful use ('harm to others'). Minimal variation in clinical features was observed across diagnostic systems. CONCLUSIONS: The World Health Organization's proposed International Classification of Diseases, 11th edition (ICD-11) classifications for substance use disorder diagnoses are highly consistent with the ICD 10th edition and the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV). Concordance between ICD-11 and the DSM 5th edition (DSM-5) varies, due largely to low levels of agreement for the ICD harmful use and DSM-5 mild use disorder. Diagnostic validity of self-reported 'harm to others' is questionable.

Demographic, physical and mental health assessments in the adolescent brain and cognitive development study: Rationale and description.

The Adolescent Brain and Cognitive Development (ABCD) Study incorporates a comprehensive range of measures assessing predictors and outcomes related to both mental and physical health across childhood and adolescence. The workgroup developed a battery that would assess a comprehensive range of domains that address study aims while minimizing participant and family burden. We review the major considerations that went into deciding what constructs to cover in the demographics, physical health and mental health domains, as well as the process of selecting measures, piloting and refining the originally proposed battery. We present a description of the baseline battery, as well as the six-month interim assessments and the one-year follow-up assessments. This battery includes assessments from the perspectives of both the parent and the target youth, as well as teacher reports. This battery will provide a foundational baseline assessment of the youth's current function so as to permit characterization of stability and change in key domains over time. The findings from this battery will also be utilized to identify both resilience markers that predict healthy development and risk factors for later adverse outcomes in physical health, mental health, and substance use and abuse.

Substance dependence among those without symptoms of substance abuse in the World Mental Health Survey.

The World Health Organization (WHO) World Mental Health (WMH) Survey Initiative uses the Composite International Diagnostic Interview (CIDI). The first 13 surveys only assessed substance dependence among respondents with a history of substance abuse; later surveys also assessed substance dependence without symptoms of abuse. We compared results across the two sets of surveys to assess implications of the revised logic and develop an imputation model for missing values of lifetime dependence in the earlier surveys. Lifetime dependence without symptoms of abuse was low in the second set of surveys (0.3% alcohol, 0.2% drugs). Regression-based imputation models were built in random half-samples of the new surveys and validated in the other half. There were minimal differences for imputed and actual reported cases in the validation dataset for age, gender and quantity; more mental disorders and days out of role were found in the imputed cases. Concordance between imputed and observed dependence cases in the full sample was high for alcohol [sensitivity 88.0%, specificity 99.8%, total classification accuracy (TCA) 99.5%, area under the curve (AUC) 0.94] and drug dependence (sensitivity 100.0%, specificity 99.8%, TCA 99.8%, AUC 1.00). This provides cross-national evidence of the small degree to which lifetime dependence occurs without symptoms of abuse. Imputation of substance dependence in the earlier WMH surveys improved estimates of dependence.

Alcohol abuse in developed and developing countries in the World Mental Health Surveys: Socially defined consequences or psychiatric disorder?

BACKGROUND: Previous single country research has raised concerns that: (1) the DSM-IV diagnosis of alcohol abuse (AA) is met primarily through the hazardous use criterion related to drinking and driving and (2) that the hazardous use and social consequences AA criteria primarily reflect varying socioeconomic and cultural factors rather than psychiatric disorder. METHODS: Using representative cross-national data from the 21 countries in the World Mental Health surveys, adults meeting DSM-IV lifetime criteria for AA but not dependence from 10 developed (n=46,071) and 11 developing (n=49,761) countries were assessed as meeting AA with the hazardous use or the social consequences criteria. RESULTS: Between 29.3% (developed) and 16.2% (developing) of respondents with AA met only the hazardous use criterion. AA cases with and without hazardous use were similar in age-of-onset, course, predictors, and psychopathological consequences in both developed and developing countries. DISCUSSION AND CONCLUSIONS: Despite some associations of the AA criteria with socioeconomic factors, the hazardous use and social consequences criteria were significantly associated with psychiatric predictors and sequelae. The findings indicate that these criteria reflect psychiatric disorder and are appropriate for inclusion as DSM-5 Alcohol Use Disorder criteria. SCIENTIFIC SIGNIFICANCE: These findings support a psychiatric rather than a sociocultural view of the hazardous use and social consequences symptoms and provide evidence that they are appropriate diagnostic criteria cross-nationally with utility in a wide range of socioeconomic environments. This suggests consideration for their adoption by ICD-11. Further research is needed on the implications of these results for prevention and treatment.

Revisiting the concepts of risk and protective factors for understanding the etiology and development of substance use and substance use disorders: implications for prevention.

Over the past 20 years we have accumulated a greater knowledge and understanding of the genetic, neurobiological, and behavioral factors that may be associated with young people initiating the use of drugs and other substances and to progressing from use to abuse and dependence. This knowledge suggests that individuals may be "predisposed" to substance use disorders (SUD) and that the actual engagement in these behaviors depends on their environmental experiences from micro to macro levels. This paper summarizes this knowledge base and supports a developmental framework that examines the interaction of posited genetic, psychological, and neurobiological "predispositions" to SUD and those environmental influences that exacerbate this vulnerability.

Smoking and suicidal behaviors in the National Comorbidity Survey: Replication.

Controversy exists about the role of mental disorders in the consistently documented association between smoking and suicidal behavior. This controversy is addressed here with data from the nationally representative National Comorbidity Survey-Replication (NCS-R). Assessments were made of 12-month smoking, suicidal behaviors (ideation, plans, attempts), and DSM-IV disorders (anxiety, mood, impulse-control, and substance use disorders). Statistically significant odds ratios (2.9-3.1) were found between 12-month smoking and 12-month suicidal behaviors. However, the associations of smoking with the outcomes became insignificant with controls for DSM-IV mental disorders. Although clear adjudication among contending hypotheses about causal mechanisms cannot be made from the cross-sectional NCS-R data, the results make it clear that future research on smoking and suicidal behaviors should focus more centrally than previous research on mental disorders either as common causes, markers, or mediators.

Prenatal drug exposure effects on subsequent vulnerability to drug abuse.

Research has shown that both prenatal alcohol and tobacco exposure are associated with increased risk of significant adverse medical, developmental, and behavioral outcomes including substance abuse. Research on the outcomes of prenatal exposure to illicit drugs (PNDE) has also found increased physical and behavioral problems for gestationally drug-exposed children. However, a clear picture has not emerged on whether the consequences of PNDE are independent from those associated with having a substance abusing parent and whether PNDE increases vulnerability to drug abuse. Because of its typical co-occurrence with factors inherent in having a drug-abusing parent, PNDE is at least a marker of significant increased risk for a range of negative outcomes including greater vulnerability to substance abuse. Although a review of the relevant research literatures indicates that the direct consequences of PNDE appear to be generally both subtle and nonglobal, PNDE does appear to have negative developmental and behavioral outcomes, and there is evidence that it is a modest direct contributor to increased substance abuse vulnerability.

Prevalence of marijuana use disorders in the United States: 1991-1992 and 2001-2002.

CONTEXT: Among illicit substance use disorders, marijuana use disorders are the most prevalent in the population. Yet, information about the prevalence of current Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) marijuana use disorders and how prevalence has changed is lacking. OBJECTIVE: To examine changes in the prevalence of marijuana use, abuse, and dependence in the United States between 1991-1992 and 2001-2002. DESIGN, SETTING, AND PARTICIPANTS: Face-to-face interviews were conducted in 2 large national surveys conducted 10 years apart: the 1991-1992 National Longitudinal Alcohol Epidemiologic Survey ([NLAES] n = 42,862) and the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions ([NESARC] n = 43,093). MAIN OUTCOME MEASURES: Rates of past year marijuana use, abuse, and dependence. RESULTS: Among the adult US population, the prevalence of marijuana use remained stable at about 4.0% over the past decade. In contrast, the prevalence of DSM-IV marijuana abuse or dependence significantly (P =.01) increased between 1991-1992 (1.2%) and 2001-2002 (1.5%), with the greatest increases observed among young black men and women (P<.001) and young Hispanic men (P =.006). Further, marijuana use disorders among marijuana users significantly increased (P =.002) in the absence of increased frequency and quantity of marijuana use, suggesting that the concomitant increase in potency of delta-9-tetrahydrocannabinol (Delta9-THC) may have contributed to the rising rates. CONCLUSIONS: Despite the stability in the overall prevalence of marijuana use, more adults in the United States had a marijuana use disorder in 2001-2002 than in 1991-1992. Increases in the prevalence of marijuana use disorders were most notable among young black men and women and young Hispanic men. Although rates of marijuana abuse and dependence did not increase among young white men and women, their rates have remained high. The results of this study underscore the need to develop and implement new prevention and intervention programs targeted at youth, particularly minority youth.

Introduction to the special issue on the impact of childhood psychopathology interventions on subsequent substance abuse: pieces of the puzzle.

Studies of adolescents and adults have reported high levels of co-occurrence of substance abuse with other psychiatric disorders, suggesting influence between the conditions. The comorbidity seems complex and variable, indicating that there may be more than I type of association between the comorbid disorders. When occurring in childhood. some of the frequently comorbid psychopathologies typically precede later drug and alcohol abuse and may have implications for substance abuse prevention as early risk indicators and as targets for intervention. Research discussed in this article and in this special issue provides a foundation for investigating the question of whether effective treatment of childhood psychopathologies can prevent or at least mitigate substance abuse for some adolescents. Clinical, research, and policy implications are discussed.