Psychological mechanisms of enhanced risk of addiction in children of alcoholics: a dual pathway?

Reward-Modulated Response Inhibition, Cognitive Shifting, and the Orbital Frontal Cortex in Early Adolescence

Immaturities in cognitive shifting are associated with adolescent risk behaviors. The orbital frontal cortex (OFC) regulates reward processing and response inhibition. This study tested the relationship between cognitive shifting, OFC activity, and reward-modulated response inhibition in young adolescents. An fMRI antisaccade (AS) paradigm examined the effects of reward conditions on inhibitory response and OFC processing. A validated self-report inventory assessed cognitive shifting. Compared to neutral, reward trials showed better AS performance and increased OFC activation. Cognitive shifting positively associated with AS performance in reward and neutral trials. Poorer cognitive shifting predicted greater OFC activation. Results indicate lower OFC efficiency, as greater activation to achieve correct performance, underlies cognitive shifting problems. These neurocognitive impairments are relevant for understanding adolescent risk behaviors.

Sibling genes as environment: Sibling dopamine genotypes and adolescent health support frequency dependent selection

While research consistently suggests siblings matter for individual outcomes, it remains unclear why. At the same time, studies of genetic effects on health typically correlate variants of a gene with the average level of behavioral or health measures, ignoring more complicated genetic dynamics. Using National Longitudinal Study of Adolescent Health data, we investigate whether sibling genes moderate individual genetic expression. We compare twin variation in health-related absences and self-rated health by genetic differences at three locations related to dopamine regulation and transport to test sibship-level cross-person gene-gene interactions. Results suggest effects of variation at these genetic locations are moderated by sibling genes. Although the mechanism remains unclear, this evidence is consistent with frequency dependent selection and suggests much genetic research may violate the stable unit treatment value assumption.

Evocative gene-parenting correlations and academic performance at first grade: an exploratory study

Academic performance during the first years of school lays the groundwork for subsequent trajectories of academic success throughout childhood and adolescence. The current study tests a model according to which a gene-parenting correlation in the first 3 years of life is associated with subsequent psychosocial adjustment and then academic performance in the first grade (as indicated by teachers' assessment of academic behavior and two subscales of the Woodcock-Johnson Test of Achievement, Third Edition). Drawing on multiple waves of data from the Durham Child Health and Development Study, we find that risk alleles for dopamine receptor genes (dopamine receptor D4 for girls, dopamine receptor D2 for boys) are associated with less sensitive parenting. For girls, parenting mediates the link between dopamine receptor D4 and all academic outcomes. There is some indication that parenting also influences girls' withdrawn behavior in the classroom, which in turn influences teachers' assessments of academic performance. For boys, some evidence suggests that parenting is associated with emotion regulation, which is associated with teachers' assessments of academic behavior and both subscales of the Woodcock-Johnson. Replications of this exploratory study are necessary, but these findings provide a first step in understanding how evocative correlations in the home may predict indicators of psychosocial adjustment that in turn influence performance and achievement at school.

Genetic interactions with prenatal social environment: effects on academic and behavioral outcomes

Numerous studies report gene-environment interactions, suggesting that specific alleles have different effects on social outcomes depending on environment. In all these studies, however, environmental conditions are potentially endogenous to unmeasured genetic characteristics. That is, it could be that the observed interaction effects actually reflect underlying genetic tendencies that lead individuals into certain environments. What is critical to move this literature forward is random environmental variation that we know is not correlated with innate characteristics of subjects. We exploit a natural experiment that randomizes a particular stressor-birth weight discordance within twin pairs-to address this challenge and ask: Do random differences in early environment (prenatal nutrition) moderate genetic effects on depression, delinquency, or GPA? Using Add Health data, the only consistently significant allele-birth weight interaction we reveal works in the opposite direction of Caspi et al.'s classic finding regarding the interaction of maltreatment with genetic variation in the serotonin transporter promoter. Less robust interactions found for DRD2 and MAOA are consistent with this pattern that reverses prior findings. These results do not necessarily overturn existing research but support our methodological point that gene-environment research must address endogeneity.

Clinical and pathological features of alcohol-related brain damage

One of the sequelae of chronic alcohol abuse is malnutrition. Importantly, a deficiency in thiamine (vitamin B(1)) can result in the acute, potentially reversible neurological disorder Wernicke encephalopathy (WE). When WE is recognized, thiamine treatment can elicit a rapid clinical recovery. If WE is left untreated, however, patients can develop Korsakoff syndrome (KS), a severe neurological disorder characterized by anterograde amnesia. Alcohol-related brain damage (ARBD) describes the effects of chronic alcohol consumption on human brain structure and function in the absence of more discrete and well-characterized neurological concomitants of alcoholism such as WE and KS. Through knowledge of both the well-described changes in brain structure and function that are evident in alcohol-related disorders such as WE and KS and the clinical outcomes associated with these changes, researchers have begun to gain a better understanding of ARBD. This Review examines ARBD from the perspective of WE and KS, exploring the clinical presentations, postmortem brain pathology, in vivo MRI findings and potential molecular mechanisms associated with these conditions. An awareness of the consequences of chronic alcohol consumption on human behavior and brain structure can enable clinicians to improve detection and treatment of ARBD.

Associations of the DRD2 TaqIA polymorphism with impulsivity and substance use: preliminary results from a clinical sample of adolescents

BACKGROUND

The A1 allele of the TaqIA polymorphism (rs1800497) in the dopamine D2 receptor gene (DRD2) has been associated with substance use. It is unclear whether this allele is a marker for an underlying propensity for specifically developing a substance use disorder, or more generally to developing an externalizing psychiatric disorder highly correlated with substance use. It is also possible that DRD2 is related to a behavioral phenotype common to externalizing disorders and substance use.

METHOD

Data was obtained from 104 psychiatrically hospitalized adolescents in a larger assessment study. Adolescents were genotyped for the DRD2 TaqIA site, grouped as carriers of the A1 allele (A1+) or homozygous for the A2 allelle (A1-). Associations of the presence of the A1 allele with externalizing disorders, the intermediate phenotype of impulsivity, and measures of alcohol and drug use were examined.

RESULTS

A diagnosis of conduct disorder and impulsive behavior were both associated with severity of problem drinking and/or drug use. Further, interaction effects were found between the DRD2 TaqIA polymorphism and conduct disorder (trend level) as well as A1+ status and impulsivity, such that adolescents who were carriers of the A1 allele, and had conduct disorder or impulsive behavior, reported higher levels of problematic alcohol use than those who were non-carriers (A2/A2 or A1-). The same interaction effect between this polymorphism and impulsivity was found for severity of problem drug use. In contrast, no interaction effects were found between the DRD2 allele status and ADHD on severity of problem drinking or drug use.

DISCUSSION

These results suggest that the well documented relationship between conduct disorder, the behavioral phenotype of impulsivity, and problematic alcohol/drug use among adolescents may be moderated by A1 carrier status of the DRD2 gene.

Bidirectional genetic and environmental influences on mother and child behavior: the family system as the unit of analyses

Family systems theory proposes that an individual's functioning depends on interactive processes within the self and within the context of dyadic family subsystems. Previous research on these processes has focused largely on behavioral, cognitive, and psychophysiological properties of the individual and the dyad. The goals of this study were to explore genetic and environmental interactions within the family system by examining how the dopamine receptor D2 gene (DRD2) A1+ polymorphism in mothers and children relates to maternal sensitivity, how maternal and child characteristics might mediate those effects, and whether maternal sensitivity moderates the association between DRD2 A1+ and child affective problems. Evidence is found for an evocative effect of child polymorphism on parenting behavior, and for a moderating effect of child polymorphism on the association between maternal sensitivity and later child affective problems. Findings are discussed from a family systems perspective, highlighting the role of the family as a context for gene expression in both mothers and children.

Alcohol and drug expectancies as anticipated changes in affect: negative reinforcement is not sedation

Goldman and Darkes (2004) argued that all three basic alcohol-expectancy factors can be assessed with a brief questionnaire (AEMax), related to the circumplex model of emotion. I argue that negative reinforcement, one of the three basic expectancy factors, is not assessed with the AEMax. Importantly, negative reinforcement is positively related to problem drinking while sedation (the AEMax-factor that comes closest) is not. In a new dataset (from 119 students, collected in 2002), I demonstrate that sedation is related to negative expectancies and not to negative reinforcement. Different ways to assess all major expectancy factors are proposed.

Children of alcoholics in Spain: from risk to pathology. Results from the ALFIL program

OBJECTIVE

To identify the possible risk factors and negative outcomes associated with parental alcoholism. A secondary aim was to determine the influence of the family density of alcoholism on children of alcoholics' (COAs) psychological functioning.

METHOD

A multisite epidemiological study was conducted in 8 Spanish cities, recruiting a total sample of 371 COAs (whose parents were in contact with alcohol treatment centers and accepted to participate in this study) and 147 controls (from schools in the same localities as COAs). Both groups were 6-17 years old and received a comprehensive evaluation of mental disorders (no symptoms, subclinical symptoms or clinical diagnosis for each disorder; according to DSM-IV criteria); alcohol and other substance use (none, occasional, regular and risky consumption); school achievement (low, middle and high) and other academic performance indicators (WISC-R Information and Arithmetic subtests, school support activities and failed subjects and courses). Lastly, several cognitive functions were measured by the WISC-R Similarities, Block Design and Digit Symbol subtests, the Toulouse-Piéron test and the Stroop test. Logistic regression methods were used to compare both groups and a linear regression model was used to determine the influence of the family density of alcoholism. The following confounding variables were controlled for: age, gender, socio-economic status and family cohesion.

RESULTS

Children of alcoholics' were twice as likely as controls to present subclinical symptoms and four times more likely than controls to have a definite diagnosis of any mental disorder. More specifically, COAs had a significantly higher risk than controls of attention deficit disorder/hyperactivity, depression, phobias, enuresis and tics. COAs also tended to have more symptoms of generalized anxiety disorder. COAs had worse results on all the cognitive tests used and their risk of low school achievement was nine times higher than that of controls. Family density of alcoholism was significantly related to several psychiatric disorders and to low academic and cognitive performance in these children.

CONCLUSION

Children of alcoholics' whose parents are in contact with treatment centers in Spain constitute a target group for selective prevention, as they have a higher risk of different negative outcomes, which mainly include attention disorders and other cognitive deficits, depression and anxiety.

Prefrontal Cortex, Thalamus, and Cerebellar Volumes in Adolescents and Young Adults with Adolescent-Onset Alcohol Use Disorders and Comorbid Mental Disorders

BACKGROUND

In adults, prefrontal, thalamic, and cerebellar brain injury is associated with excessive ethanol intake. As these brain structures are actively maturing during adolescence, we hypothesized that subjects with adolescent-onset alcohol use disorders, compared with control subjects, would have smaller brain volumes in these areas. Thus, we compared prefrontal-thalamic-cerebellar measures of adolescents and young adults with adolescent-onset alcohol use disorders (AUD, defined as DSM-IV alcohol dependence or abuse) with those of sociodemographically similar control subjects.

METHODS

Magnetic resonance imaging was used to measure prefrontal cortex, thalamic, and cerebellar volumes in 14 subjects (eight males, six females) with an AUD (mean age, 17.0+/-2.1 years) and 28 control subjects (16 males, 12 females; 16.9+/-2.3 years). All AUD subjects were recruited from substance abuse treatment programs and had comorbid mental disorders.

RESULTS

Subjects with alcohol use disorders had smaller prefrontal cortex and prefrontal cortex white matter volumes compared with control subjects. Right, left, and total thalamic, pons/brainstem, right and left cerebellar hemispheric, total cerebellar, and cerebellar vermis volumes did not differ between groups. There was a significant sex-by-group effect, indicating that males with an adolescent-onset AUD compared with control males had smaller cerebellar volumes, whereas the two female groups did not differ in cerebellar volumes. Prefrontal cortex volume variables significantly correlated with measures of alcohol consumption.

CONCLUSIONS

These findings suggest that a smaller prefrontal cortex is associated with early-onset drinking in individuals with comorbid mental disorders. Further studies are warranted to examine if a smaller prefrontal cortex represents a vulnerability to, or a consequence of, early-onset drinking.

Adverse childhood experiences and personal alcohol abuse as an adult

Adult alcohol abuse has been linked to childhood abuse and family dysfunction. However, little information is available about the contribution of multiple adverse childhood experiences (ACEs) in combination with parental alcohol abuse, to the risk of later alcohol abuse. A questionnaire about childhood abuse, parental alcoholism and family dysfunction while growing up was completed by adult HMO members in order to retrospectively assess the independent relationship of eight ACEs to the risk of adult alcohol abuse. The number of ACEs was used in stratified logistic regression models to assess their impact on several adult alcohol problems in the presence or absence of parental alcoholism. Each of the eight individual ACEs was associated with a higher risk alcohol abuse as an adult. Compared to persons with no ACEs, the risk of heavy drinking, self-reported alcoholism, and marrying an alcoholic were increased twofold to fourfold by the presence of multiple ACEs, regardless of parental alcoholism. Prevention of ACEs and treatment of persons affected by them may reduce the occurrence of adult alcohol problems.

Is a mild deficit in executive functions in boys related to childhood ADHD or to parental multigenerational alcoholism?

A mild deficit in executive functions has been hypothesized to be associated with attention deficit hyperactivity disorder (ADHD), with externalizing problem behaviors such as conduct disorder (CD) and with the vulnerability to alcoholism in sons of multi-generational alcoholics (SOMGAs). These three categories overlap, which raises concerns about the specificity of the hypothesized associations. In the present study, measures of executive functions (EFs) were tested in seventy-six 7- to 11-year-old boys: boys with ADHD but without a family history of addiction, SOMGAs, and controls. Specific deficits in EFs were found for boys with ADHD but not for SOMGAs. The association between a deficit in EFs and attention problems remained after controlling for externalizing problem behaviors, but not for the reverse. These results suggest that a mild deficit in EFs is specifically related to ADHD and that the deficits reported in boys with CD and in SOMGAs are due to relatively high attentional problems in these groups or due to other factors such as motivation.

Social class and substance use disorders: the value of social class as distinct from socioeconomic status

The relationship between social class and substance use disorders (SUDs) is explored and compared to the relationship between SES and SUDs. Social class and SES are two different conceptualizations of socioeconomic inequality (SEI) which emanate from two different theoretical orientations in sociology. SES is commonly used in epidemiological research and is usually measured in terms of education, income or occupational prestige. Social class is less known and less used. Here, following the work of Wright et al. (Wright, E. O., Hachen, D. and Costello, C. et al. (1982) The American class structure. American Sociological Review 47, 709-726) it is measured in terms of four types of control people have in their work place: ownership, control over budget decisions, control over other workers, and control over one's own work. Data are derived from an epidemiological survey, conducted in Israel, using a two stage sampling procedure for the identification of cases. In the first stage 4914 respondents were screened with the Psychiatric Epidemiological Research Interview (PERI). In the second stage (n = 2741), those who screened positive (and a sample of the negatives) were diagnosed by psychiatrists using a structured interview that yielded diagnoses according to the Research Diagnostic Criteria (RDC). The results indicate that those who are advantaged in terms of ownership, i.e. self-employed, have higher rates of SUDs compared to employees. Furthermore, it appears that most disorders have an onset subsequent to entry into the current job, indicating that ownership plays a causal role in the onset of SUDs rather than the other way around. These results are contrasted with those of a previous report from the same study by Dohrenwend et al. (Dohrenwend, B. P., Levav, I. and Shrout, P. E. et al. (1992) Socioeconomic status and psychiatric disorders: the causation selection issue. Science 255, 946-952) which showed just the opposite association between SES and SUDs, i.e. those who are advantaged in terms of SES have lower rates of SUDs. As an explanation of these apparently conflicting results, the possibility is entertained that social class and SES represent independent causal pathways to the onset of SUDs with social class mainly related to primary SUDs and SES mainly to secondary SUDs.

Children of alcoholics. Predictors for psychopathology and addiction

Children of alcoholics have a higher risk of psychopathology and alcoholism. Therefore, in 1993 the Amsterdam Institute for Addiction Research initiated a study on vulnerability markers and risk factors in children of alcoholics, aimed at identifying predictors for the development of psychopathology and addiction in children of alcoholics. This article provides a summary of the background, rationales and aims of the study. With more specific and sensitive biological vulnerability markers that indicate risk status, more effective preventive interventions might become available. The biochemical part of the study aims at answering the question whether adenylate cyclase is a vulnerability marker for alcoholism. The psychophysiological part is directed at event-related potentials during task performance to clarify the nature of the brain and cognitive functions that may underlie or relate to vulnerability to alcoholism. The third part, the psychological component, aims at possible psychological mechanisms of enhanced risk of addition in children of alcoholics as well as the relationship with childhood psychopathology.

Adenylate cyclase, a biochemical marker of alcoholism?

A possible biochemical vulnerability (trait) marker is examined in a cross-sectional study to determine the biochemical factors associated with the development of alcoholism in a population of non-adult children of alcoholics. The activity of adenylate cyclase, an enzyme that plays a role in the signal transduction pathway of several hormones and neurotransmitters, is assessed in blood platelets. This activity was reported to be lower in blood cells of alcoholics and abstinent alcoholics compared with that in controls. In addition, dysregulation of adenylate cyclase in the CNS of animals seems to be involved in drug-seeking behaviour. The relation between these biochemical findings and psychopathology is currently being investigated in a project by the Amsterdam Institute for Addiction Research.