Genetic and environmental contributions to age of onset of alcohol dependence symptoms in male twins

The association between HTR1B gene rs13212041 polymorphism and onset of alcohol abuse

BACKGROUND

Alcohol dependence displays a wide variety of clinical phenotypes. Various typology classifications of alcoholism include age of onset of alcohol abuse as one of the major phenotypic features. Serotonergic changes have been associated with alcoholism, while serotonin receptors type 1B (5-HT1B) play an important role in regulating serotonergic neurotransmission. The rs13212041 polymorphism modulates the expression of HTR1B gene coding for 5-HT1B receptor. This study examined the association of platelet serotonin (5-HT) and HTR1B gene with the onset of alcohol abuse in alcohol-dependent subjects.

MATERIALS AND METHODS

Determination of platelet 5-HT concentration and genotyping of rs13212041 HTR1B gene polymorphism were performed in 613 alcohol-dependent patients, subdivided according to early/late onset (before/after 25 years of age) of alcohol abuse.

RESULTS

Alcohol-dependent individuals with CC genotype were more frequent in the group with early onset of alcohol abuse compared to carriers of T allele. Besides HTR1B genotype, age and gender, but not platelet 5-HT, were major variables associated with the onset of alcohol abuse. Platelet 5-HT concentration was not significantly different between patients with early and late onset of alcohol abuse, or patients carrying various HTR1B genotypes. Although we observed no influence of co-variables such as age, gender, or somatic and psychiatric comorbidities, platelet 5-HT concentration was significantly affected by smoking.

CONCLUSION

These findings support potential involvement of 5-HT1B receptors in the onset of alcohol abuse and development of alcohol dependence. Additionally, the results of our study emphasize the importance of controlling for smoking status, as one of the significant confounding factors influencing platelet 5-HT concentration.

Amygdala-orbitofrontal functional connectivity mediates the relationship between sensation seeking and alcohol use among binge-drinking adults

BACKGROUND

Decreased amygdala-orbitofrontal cortex (OFC) neural functional connectivity (FC) positively predicts alcohol use among adolescents. Low amygdala-OFC FC is also associated with poor emotion regulation, a trait robustly linked to alcohol use. Thus, decreased amygdala-OFC connectivity may represent a risk factor for the development of alcohol use disorder (AUD) via impaired emotion regulation or reward processing. In this study, we examined amygdala-OFC FC among young adult binge drinkers at high risk for AUD. We also tested if amygdala-OFC FC mediates the relationship between externalizing personality traits and alcohol use.

METHODS

Healthy male and female (n = 39) binge drinkers completed a resting state fMRI scan and the Eysenck Impulsive Personality questionnaire. We utilized seed-based connectivity of the left and right amygdala to prefrontal regions as well as mediation analysis.

RESULTS

Individuals with higher weekly alcohol use displayed decreased right amygdala-OFC FC. Furthermore, high trait venturesomeness, but not impulsivness, was associated with decreased right amygdala-OFC FC. Finally, right amygdala-OFC FC mediated the relationship between trait venturesomeness and weekly drinking; individuals with high trait venturesomeness displayed decreased right amygdala-OFC FC, which in turn predicted greater weekly drinking.

CONCLUSIONS

Our findings corroborate and extend the adolescent literature by showing that decreased amygdala-OFC FC is associated with higher alcohol consumption among adults at elevated risk for AUD. This study also demonstrates for the first time that this neural profile reflects a tendency to sensation seeking. In sum, our findings suggest that amygdala-OFC FC may be an objective neural target for alcohol use prevention and intervention.

Using an Event-History with Risk-Free Model to Study the Genetics of Alcoholism

Case–control genetic association studies typically ignore possible later disease onset in currently healthy subjects and assume that subjects with diseases equally contribute to the likelihood for inference, regardless of their onset age. Therefore, we used an event-history with risk-free model to simultaneously characterize alcoholism susceptibility and onset age in 65 independent non-Hispanic Caucasian males in the Collaborative Study on the Genetics of Alcoholism. Following data quality control, we analysed 22 single nucleotide polymorphisms (SNPs) on 12 candidate genes. The single-SNP analysis showed that the dominant minor allele of rs2134655 on DRD3 increases alcoholism susceptibility; the dominant minor allele of rs1439047 on NTRK2 delays the alcoholism onset age, but the additive minor allele of rs172677 on GRIN2B and the dominant minor allele of rs63319 on ALDH1A1 advance the alcoholism onset age; and the dominant minor allele of rs1079597 on DRD2 shortens the onset age range. Similarly, multiple-SNPs analysis revealed joint effects of rs2134655, rs172677 and rs1079597, with an adjustment for habitual smoking. This study provides a more comprehensive understanding of the genetics of alcoholism than previous case–control studies.

Does familial risk for alcohol use disorder predict alcohol hangover?

AIMS

Positive family history of alcohol use disorder (FHP), a variable associated with propensity for alcohol use disorder (AUD), has been linked with elevated hangover frequency and severity, after controlling for alcohol use. This implies that hangover experiences may be related to AUD. However, inadequate control of alcohol consumption levels, low alcohol dose and testing for hangover during the intoxication phase detract from these findings. Here, we present further data pertinent to understanding the relationship between family history and alcohol hangover.

METHODS

Study 1 compared past year hangover frequency in a survey of 24 FHP and 118 family history negative (FHN) individuals. Study 2 applied a quasi-experimental naturalistic approach assessing concurrent hangover severity in 17 FHP and 32 FHN individuals the morning after drinking alcohol. Both studies applied statistical control for alcohol consumption levels.

RESULTS

In Study 1, both FHP status and estimated blood alcohol concentration on the heaviest drinking evening of the past month predicted the frequency of hangover symptoms experienced over the previous 12 months. In Study 2, estimated blood alcohol concentration the previous evening predicted hangover severity but FHP status did not.

CONCLUSIONS

FHP, indicating familial risk for AUD, was not associated with concurrent hangover severity but was associated with increased estimates of hangover frequency the previous year.

Three measures of explained variation for correlated survival data under the proportional hazards mixed-effects model

Measures of explained variation are useful in scientific research, as they quantify the amount of variation in an outcome variable of interest that is explained by one or more other variables. We develop such measures for correlated survival data, under the proportional hazards mixed-effects model. Because different approaches have been studied in the literature outside the classical linear regression model, we investigate three measures R(2) , Rres2, and ρ(2) that quantify three different population coefficients. We show that although the three population measures are not the same, they reflect similar amounts of variation explained by the predictors. Among the three measures, we show that R(2) , which is the simplest to compute, is also consistent for the first population measure under the usual asymptotic scenario when the number of clusters tends to infinity. The other two measures, on the other hand, all require that in addition the cluster sizes be large. We study the properties of the measures both analytically and through simulation studies. We illustrate their different usage on a multi-center clinical trial and a recurrent events data set. Copyright © 2016 John Wiley & Sons, Ltd.

Initial subjective reward: single-exposure conditioned place preference to alcohol in mice

Most adults consume alcohol with relative impunity, but about 10–20% of users persist (or progress) in their consumption, despite mounting and serious repercussions. Identifying at-risk individuals before neuroadaptative changes associated with chronic use become well ingrained is thus a key step in mitigating and preventing the end stage disease and its devastating impacts. Explaining liability has been impeded, in part, by the absence of animal models for assessing initial sensitivity to the drug's reinforcing properties, an important endophenotype in the trajectory toward excessive drinking. Here we assess the initial rewarding effects of the drug in a novel application of the conditioned place preference paradigm. In contrast to previous studies that have all employed repeated drug administration, we demonstrated a robust preference for a context paired with a single exposure to 1.5 g/kg EtOH in male and female subjects of three strains. This model validates an assay of initial sensitivity to the subjective rewarding effects of alcohol, a widely used drug with multifarious impacts on both brain and society, and provides a new tool for theory-driven endophenotypic pharmacogenetic approaches to understanding and treating addiction.

Family history of alcohol use disorders and neuromaturation: a functional connectivity study with adolescents

BACKGROUND

A positive family history (FHP) of alcohol use disorders (AUD) is linked to increased risk for personal AUD, but the mechanisms behind this risk are unclear. Previous research suggests that a subtle neurodevelopmental lag in FHP adolescents may contribute to risk for future AUD.

METHODS

Functional magnetic resonance imaging (fMRI) response to a spatial working memory (SWM) task was examined for markers of neuromaturational delay in 85 youth with and without FHP. It was hypothesized that FHP adolescents (n = 24, ages 12-14 years), as compared to matched FHN youth (n = 26, ages 12-14 years), would show less similarity to brain connectivity observed in older adolescents (n = 35, ages 16-20 years) and that statistical comparison of SWM functional connectivity models would differentiate FHN and FHP youth. Structural equation modeling tested the fit of brain response connectivity between FH groups and against the older-adolescent model.

RESULTS

Patterns of connectivity were more similar between older adolescent and FHN than FHP adolescents; FHP youth demonstrated higher association between right posterior and left frontal brain regions than FHN and older adolescent youth. Comparison of FH groups indicated a significant difference on the pathway from the right superior parietal lobule to the left middle frontal gyrus.

CONCLUSIONS

These findings provide additional support for the notion of a neuromaturational lag in FHP youth. Protracted neuromaturation may be a mechanism by which FH increases risk for alcohol dependence, and this less mature neural connectivity pattern may provide a novel endophenotype for identifying youth at risk for drinking problems.

The genetics of alcohol dependence

Alcohol consumption dates back to the Neolithic period, and alcohol dependence contributes substantially to the current global burden of disease. Despite this, optimal therapies and preventive strategies are lacking. Formal genetic studies of alcohol dependence have shown that genetic factors play as large a role in disease etiology as environmental factors. Molecular genetic studies may identify causal factors and facilitate the development of novel preventive and therapeutic approaches. Whereas earlier studies involved the use of linkage- and candidate-gene approaches, recent years have witnessed the introduction of genome-wide association studies (GWAS). The present review provides a brief overview of the findings of formal genetic studies, summarizes the results of earlier molecular-genetic investigations, and presents a detailed overview of all published GWAS in the field of alcohol dependence research. To date, few genome-wide significant findings have been reported. However, through the polygenic approach, GWAS have both confirmed the existence of a multitude of novel risk genes and indicated interesting new candidates.

Structural models of the comorbidity of internalizing disorders and substance use disorders in a longitudinal birth cohort

PURPOSE

The present study examined the associations between internalizing disorders and substance use disorders using structural equation models to examine the relative contributions of common fixed confounding factors and direct causal pathways, and to determine the direction of causality.

METHODS

Data were gathered during the course of the Christchurch Health and Development Study, a 25-year longitudinal study of a birth cohort of New Zealand children (n = 953). Measures included DSM-IV symptom criteria for major depression, anxiety disorders, alcohol abuse/dependence, nicotine dependence, and illicit drug abuse/dependence, ages 18, 21, and 25.

RESULTS

Structural equation modeling showed that for depression and substance use disorder, the best-fitting model was the one in which the associations were explained by a combination of common fixed factors and direct causal pathways from substance use to depression. A similar pattern emerged for anxiety disorders and (1) nicotine dependence, and (2) illicit drug abuse/dependence. The comorbidity of anxiety disorder and alcohol abuse/dependence was best explained by a model that included common fixed factors and a reciprocal pathway between these disorders. Decomposition of the correlations between internalizing disorders and substance use disorders showed that most of the correlation arose from direct causal pathways between disorders.

CONCLUSIONS

The findings suggest that the comorbidity between internalizing disorders and substance use disorders can be attributed to both common fixed factors and direct causal pathways between substance use disorder and internalizing disorder. The evidence suggests that, in most cases, the most plausible explanation of causality is the one in which substance use disorder increases the risk of internalizing disorder.

arouser reveals a role for synapse number in the regulation of ethanol sensitivity

A reduced sensitivity to the sedating effects of alcohol is a characteristic associated with alcohol use disorders (AUDs). A genetic screen for ethanol sedation mutants in Drosophila identified arouser (aru), which functions in developing neurons to reduce ethanol sensitivity. Genetic evidence suggests that aru regulates ethanol sensitivity through its activation by Egfr/Erk signaling and its inhibition by PI3K/Akt signaling. The aru mutant also has an increased number of synaptic terminals in the larva and adult fly. Both the increased ethanol sensitivity and synapse number of the aru mutant are restored upon adult social isolation, suggesting a causal relationship between synapse number and ethanol sensitivity. We thus show that a developmental abnormality affecting synapse number and ethanol sensitivity is not permanent and can be reversed by manipulating the environment of the adult fly.

Individuals family history positive for alcoholism show functional magnetic resonance imaging differences in reward sensitivity that are related to impulsivity factors

BACKGROUND

Substance-abusing individuals tend to display abnormal reward processing and a vulnerability to being impulsive. Detoxified alcoholics show differences in regional brain activation during a monetary incentive delay task. However, there is limited information on whether this uncharacteristic behavior represents a biological predisposition toward alcohol abuse, a consequence of chronic alcohol use, or both.

METHODS

We investigated proposed neural correlates of substance disorder risk by examining reward system activity during a monetary incentive delay task with separate reward prospect, reward anticipation, and reward outcome phases in 30 individuals with and 19 without family histories of alcoholism. All subjects were healthy, lacked DSM-IV past or current alcohol or substance abuse histories, and were free of illegal substances as verified by a urine toxicology screening at the time of scanning. Additionally, we explored specific correlations between task-related nucleus accumbens (NAcc) activation and distinct factor analysis-derived domains of behavioral impulsivity.

RESULTS

During reward anticipation, functional magnetic resonance imaging data confirmed blunted NAcc activation in family history positive subjects. In addition, we found atypical activation in additional reward-associated brain regions during additional task phases. We further found a significant negative correlation between NAcc activation during reward anticipation and an impulsivity construct.

CONCLUSIONS

Overall, results demonstrate that sensitivity of the reward circuit, including NAcc, is functionally different in alcoholism family history positive individuals in multiple regards.

Association between the 5-HTR1B gene polymorphisms and alcohol dependence in a Han Chinese population

The human serotonin receptor 1B (HRT1B) plays an important role in regulating serotonin release. Previous research has suggested that the genetic variation of the HTR1B gene may confer susceptibility to alcoholism or some subtypes of alcohol dependence, but the evidence has been inconsistent. The aim of the present study is to examine whether polymorphic variants of the HTR1B gene are associated with alcohol dependence subtypes or drinking-related behaviors in Chinese Han population. Alcohol-dependent (AD) male patients (n=135) and controls (n=143) were genotyped for two polymorphisms: A161T in the promoter region and the synonymous variation G861C in the coding region of HTR1B. The results showed that the A161T polymorphism was associated with alcohol dependence (T vs. A allele: p=0.002; OR=2.18, 95% CI: 1.32-3.60). This association was strengthened in those with positive family history (OR=3.12, 95% CI: 1.71-5.70) and/or early onset (OR=4.53, 95% CI: 2.18-9.44) of alcohol dependence. The A161T variant was also significantly associated with age of onset of alcoholism (p=0.001). Furthermore, there was a significant difference of haplotypic frequencies between patients and controls (χ(2)=14.84, df=3, p=0.002), with one common haplotype AG of being significantly underrepresented among the patient group compared to the control group (34% vs. 47.7%, permutation p=0.0034; OR=0.56; 95% CI: 0.39-0.79). These findings confirm HTR1B as a susceptibility gene for alcohol dependence in the sample of Chinese Han population. The HTR1B A-161T polymorphism may be particularly valuable as a functional genetic marker for alcoholism and merits additional study.

Priming deficiency in male subjects at risk for alcoholism: the N4 during a lexical decision task

BACKGROUND

While there is extensive literature on the relationship between the P3 component of event-related potentials (ERPs) and risk for alcoholism, there are few published studies regarding other potentially important ERP components. One important candidate is the N4(00) component in the context of semantic processing, as abnormalities in this component have been reported for adult alcoholics.

METHOD

A semantic priming task was administered to nonalcohol dependent male offspring (18 to 25 years) of alcoholic fathers [high risk (HR) n = 23] and nonalcoholic fathers [low risk (LR) n = 28] to study whether the 2 groups differ in terms of the N4 component. Subjects were presented with 150 words and 150 nonwords. Among the words, 50 words (primed) were preceded by their antonyms (prime, n = 50), whereas the remaining 50 words were unprimed. For the analysis, N4 amplitude and latency as well as behavioral measures for the primed and unprimed words were considered.

RESULTS

A significant interaction effect was observed between semantic condition and group, where HR subjects did not show N4 attenuation for primed stimuli.

CONCLUSION

The lack of N4 attenuation to primed stimuli and/or inability to differentiate between primed and unprimed stimuli, without latency and reaction time being affected, suggest deficits in semantic priming, especially in semantic expectancy and/or postlexical semantic processing in HR male offspring. Further, it indicates that it might be an electrophysiological endophenotype that reflects genetic vulnerability to develop alcoholism.

Initial evidence of an association between OPRM1 and adolescent alcohol misuse

BACKGROUND

Considerable research efforts have attempted to identify genes associated with alcoholism among adults, yet few studies have examined adolescents. Identifying genes associated with alcohol misuse in youth is important given that the relative contribution of genetic and environmental influences on alcoholism varies across development. The purpose of this study was to examine the association between a polymorphism of the mu-opioid receptor gene (OPRM1) and alcohol misuse in a sample of youth and to test whether heightened sensitivity to the reinforcing effects of alcohol mediated this relationship.

METHODS

Adolescents (n = 187; mean age = 15.4 years; 47.6% female) were genotyped for A118G (rs1799971), a single-nucleotide polymorphism (SNP) of the OPRM1 gene, and assessed for alcohol use disorder (AUD) diagnoses and other psychopathology. Alcohol misuse was also measured continuously to maximize detection of drinking problems in youth. Drinking motives were used to capture the extent to which youth consumed alcohol to enhance positive affect.

RESULTS

AUD groups differed significantly in terms of allelic distributions of the A118G SNP, such that 51.9% of youth with an AUD carried at least one copy of the G allele compared to 16.3% of non-AUD controls. Those who carried the G allele endorsed drinking to enhance positive affect more strongly than those who were homozygous for the A allele and drinking to enhance positive affect mediated the association between OPRM1 and alcohol-related problems.

CONCLUSIONS

These data build on findings from adult studies and provide the first evidence that a polymorphism of the OPRM1 receptor gene is associated with the development of early-onset alcohol-related problems during adolescence, in part, by heightening sensitivity to the reinforcing effects of alcohol.

Genome-wide association study of alcohol dependence

CONTEXT

Alcohol dependence is a serious and common public health problem. It is well established that genetic factors play a major role in the development of this disorder. Identification of genes that contribute to alcohol dependence will improve our understanding of the mechanisms that underlie this disorder.

OBJECTIVE

To identify susceptibility genes for alcohol dependence through a genome-wide association study (GWAS) and a follow-up study in a population of German male inpatients with an early age at onset.

DESIGN

The GWAS tested 524,396 single-nucleotide polymorphisms (SNPs). All SNPs with P < 10(-4) were subjected to the follow-up study. In addition, nominally significant SNPs from genes that had also shown expression changes in rat brains after long-term alcohol consumption were selected for the follow-up step.

SETTING

Five university hospitals in southern and central Germany.

PARTICIPANTS

The GWAS included 487 male inpatients with alcohol dependence as defined by the DSM-IV and an age at onset younger than 28 years and 1358 population-based control individuals. The follow-up study included 1024 male inpatients and 996 age-matched male controls. All the participants were of German descent.

MAIN OUTCOME MEASURES

Significant association findings in the GWAS and follow-up study with the same alleles.

RESULTS

The GWAS produced 121 SNPs with nominal P < 10(-4). These, together with 19 additional SNPs from homologues of rat genes showing differential expression, were genotyped in the follow-up sample. Fifteen SNPs showed significant association with the same allele as in the GWAS. In the combined analysis, 2 closely linked intergenic SNPs met genome-wide significance (rs7590720, P = 9.72 x 10(-9); rs1344694, P = 1.69 x 10(-8)). They are located on chromosome region 2q35, which has been implicated in linkage studies for alcohol phenotypes. Nine SNPs were located in genes, including the CDH13 and ADH1C genes, that have been reported to be associated with alcohol dependence.

CONCLUSIONS

This is the first GWAS and follow-up study to identify a genome-wide significant association in alcohol dependence. Further independent studies are required to confirm these findings.

A short review on the aetiology and pathophysiology of alcoholism

Alcoholism is a chronic remitting and relapsing condition; its aetiology and pathophysiology remains largely obscure despite recent advances. This review summarises the current knowledge about the causation (biological or psychological) of alcohol addiction. This involves heredity, candidate genes, alcohol metabolism regulation and the influence of alcohol in the pathophysiology of the different neurotransmitter systems. Alcohol addiction is a multifactorial phenomenon where personality structure, individual state of mind and social influences are in constant interaction with brain neurobiology and pathophysiology. This disorder influences different sexes in different ways and causes major problems, especially in developed societies.

On proportional hazards assumption under the random effects models

The proportional hazards mixed-effects model (PHMM) was proposed to handle dependent survival data. Motivated by its application in genetic epidemiology, we study the interpretation of its parameter estimates under violations of the proportional hazards assumption. The estimated fixed effect turns out to be an averaged regression effect over time, while the estimated variance component could be unaffected, inflated or attenuated depending on whether the random effect is on the baseline hazard, and whether the non-proportional regression effect decreases or increases over time. Using the conditional distribution of the covariates we define the standardized covariate residuals, which can be used to check the proportional hazards assumption. The model checking technique is illustrated on a multi-center lung cancer trial.

Genetic and environmental predictors of early alcohol use

BACKGROUND

The goal of the current investigation was to examine genetic and environmental predictors of early alcohol use, a potent predictor of later alcohol dependence.

METHODS

This study represents an add-on project to an investigation examining the efficacy of an intervention for maltreated children entering out-of-home care. Predictors of early alcohol use include the following: maltreatment, family loading for alcohol or substance-use disorders, and serotonin transporter genotype (5-HTTLPR; locus SLC6A4). Participants included 127 subjects: 76 maltreated children and 51 demographically matched community controls.

RESULTS

At follow-up, 29% of the maltreated children reported alcohol use, a rate more than seven times the rate observed in controls. Maltreated children also drank alcohol, on average, more than 2 years earlier than controls (11.2 vs. 13.5 years). Early alcohol use was predicted by maltreatment, 5-HTTLPR, and a gene by environment interaction, with increased risk for early alcohol use associated with the s-allele. Psychopathology at baseline, severity of maltreatment, and poor mother-child relations also predicted early alcohol use.

CONCLUSIONS

Maltreated children are at high risk for psychiatric, alcohol, and substance abuse problems. Examination of genetic and environmental risk and protective factors can help identify those who are most vulnerable and help guide prevention and intervention efforts.

Early adversity and alcohol availability persistently modify serotonin and hypothalamic–pituitary–adrenal-axis metabolism and related behavior: What experimental research on rodents and primates can tell us

Early experiences have profound influences on individual developmental trajectories. For example alcohol exposure during central nervous system development relates to a number of pathological consequences in adulthood. An increased risk of developing psychiatric disorders, like major depression and impulse-control-related pathologies is associated with alcohol exposure during fetal life and/or during adolescence. Additionally, adverse life experiences occurring early in development may exacerbate these consequences, while impinging on the same neural systems affected by precocious alcohol exposure. Conversely, a protective and/or stimulating environment may mitigate these alcohol-related negative outcomes. Experimental research in animal models constitutes a primary source of information in understanding both functional and dysfunctional human adaptations to these events. In this review, a selection of rodent and primate studies shows that developmental ethanol exposure on the one hand, and environmental treatments aimed at modifying the mother-offspring interaction on the other hand, independently modulate similar neuro-endocrine systems. In particular, we discuss the effects that the above-mentioned independent variables exert on the hypothalamic-pituitary-adrenal (HPA)-axis and on brain serotonergic pathways. Experimental evidence indicates that pathological adaptations of these systems are valuable predictors of human neuro-behavioral abnormalities like depression, impaired impulse control and alcohol abuse. Finally, a working hypothesis is proposed, which combines primate and rodent studies aimed: (i) at studying functional and pathological individual development following early ethanol consumption, and (ii) at heading towards a better definition of potential intervention strategies.

Alcohol use in families: a 15-year prospective follow-up study

AIMS

To study the prevalence of adolescents' problematic alcohol use and its parental predictors: drinking habits and socio-demographic factors.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

Questionnaires were sent regularly to the same Finnish families (n = 1132) from the onset of pregnancy (in 1986-87) to the child's age of 15 years (in 2001-02) (n = 1028). There was a total of three follow-up points.

FINDINGS

At 15 years of age, 83% of girls and 79% of boys had used alcohol; 18% of boys and 14% of girls had been drunk more than once a month. The child's permanent separation from at least one biological parent was the strongest socio-demographic predictor of adolescents drinking. Fathers' present heavy drinking and parental early drinking were the best predictors of their children's problematic alcohol use at the age of 15.

CONCLUSIONS

Knowledge of fathers' alcohol use and its time of onset may be used to determine children who are at added risk of problematic alcohol use later in life. Special guidance, support and treatment can be targeted to these families.