Timothy C. Blackson

Etiology of early age onset substance use disorder: A maturational perspective

The etiology of early age onset substance use disorder (SUD), an Axis I psychiatric illness, is examined from the perspective of the multifactorial model of complex disorders. Beginning at conception, genetic and environment interactions produce a sequence of biobehavioral phenotypes during development which bias the ontogenetic pathway toward SUD. One pathway to SUD is theorized to emanate from a deviation in somatic and neurological maturation, which, in the context of adverse environments, predisposes to affective and behavioral dysregulation as the cardinal SUD liability-contributing phenotype. Dysregulation progresses via epigenesis from difficult temperament in infancy to conduct problems in childhood to substance use by early adolescence and to severe SUD by young adulthood.

Child abuse potential in parents with histories of substance use disorder.

OBJECTIVE To examine the relationship between parental history of substances use disorders (SUDs) and abuse potential. METHOD Milners (1986) Child Abuse Potential Inventory (CAPI) was administered to fathers and mothers (with and without histories of SUDs) of 10- to 12-year-old boys. RESULTS Fathers and mothers with lifetime histories of SUDs had higher Abuse Scale scores and were more likely to score in the Elevated range (as determined by clinically significant cutoff scores) than parents without such histories. No differences were found between parents with current diagnoses of SUD and those with past (but not current) histories of SUD. Fathers and mothers with a partner who had a history of SUD were more likely to score in the Elevated range, regardless of their own SUD histories. Separate regression models revealed that, for both fathers and mothers, emotional dysregulation (positive and negative affectivity) predicted Abuse Scale scores. Additional contributors to Abuse Scale scores were SUD status in fathers, and lack of involvement with the child in mothers. CONCLUSIONS History of SUDs in both fathers and mothers increases abuse potential. Contributors to abuse potential differed in fathers and mothers, underscoring the importance of examining parents separately in child maltreatment research.

Aggressivity, inattention, hyperactivity, and impulsivity in boys at high and low risk for substance abuse.

Aggressivity, inattention, hyperactivity, and impulsivity are cardinal dimensions of externalizing behavior problems of childhood. They are diagnostic and clinical features of childhood disorders, and are thought to be linked to the subsequent development of adult disorders such as substance abuse (SA). Little is known, however, about the convergent and discriminant validity of these four constructs. We used multiple measures to develop indices of aggressivity, inattention, hyperactivity, and impulsivity in a sample of 10- to 12-year-old boys (N=183) with and without a family history of SA. Data were taken from mother reports, child reports, teacher reports, and laboratory tasks. The study aims were (1) to test the convergent and discriminant validity of aggressivity, inattention, hyperactivity, and impulsivity; (2) to examine whether the data were consistent with a model specifying the four constructs as indicators of one superordinate factor; and (3) to differentiate boys with and without a family history of SA in construct scores. The results supported the convergent and discriminant validity of the four constructs. Although discriminable, the constructs covaried strongly and were consistent with a model specifying them as indicators of a single superordinate factor. Boys with a family history of substance abuse scored higher than control boys on aggressivity, inattention, and impulsivity scores, but the groups did not differ on hyperactivity scores. The results are discussed in terms of the role of childhood behavior problems in vulnerability to SA.

The association between childhood irritability and liability to substance use in early adolescence: a 2-year follow-up study of boys at risk for substance abuse

The aim of this investigation was to determine whether irritability, defined as the propensity to experience and express anger following actual or perceived provocation, is a component of the liability to alcohol and drug abuse. Sons of substance abusing fathers (n = 40) and normal fathers (n = 56) were studied when they were 10-12 years of age and followed-up 2 years later. Hierarchical regression analysis revealed that resting salivary cortisol concentration, impulsivity and family discord measured when the subjects were 10-12 years of age explained 35% of the variance on a scale measuring irritability 2 years later. At follow-up, when the boys were 12-14 years of age, it was observed that irritability scale scores and family discord were the only variables that accounted for significance variance on a scale measuring coping via alcohol and drug use. Latency and amplitude of the N1 and P3 event-related potentials of an auditory oddball task, measured at age 10-12, were not associated with drug use at age 12-14. These results indicate that family dysfunction, stress state of the child, and low behavioral self-control additively account for a significant proportion of variance on irritability scale scores 2 years later, and that this trait, in conjunction with family discord, is associated with substance use as a coping response by early adolescence.

Temperament Mediates the Effects of Family History of Substance Abuse on Externalizing and Internalizing Child Behavior

Temperament has been hypothesized to mediate the effects of family history of substance abuse (SA) on behavioral maladjustment in children. To date no study has provided empirical evidence to support this mediation hypothesis. In this study the temperament mediation hypothesis was tested employing hierarchical regression and other linear regression procedures. “Difficult affective temperament” in fathers and sons was found to mediate the relationship between SA+ family history and behavior maladjustment in 10- to 12-year-old sons of SA+ (n=41)and SA-(n = 39) families. The authors discuss implications of the phenotype of difficult affective temperament in describing the developmental pathway to substance abuse.

Heightened motor activity level in male offspring of substance abusing fathers

Heightened activity level has been implicated in the liability for substance abuse, but no prior research has directly examined motor activity in a sample of prepubertal boys at high-risk for substance abuse. The magnitude of behavioral activity of 10-12 year-old sons of substance abusing fathers (SA +) (n = 42) and controls (SA -) (n = 60) was assessed using a microprocessor-based activity monitor during tasks that demanded significant concentration, effort, and constraint on motor activity, and when no such demands were present. Psychiatric status, measures of temperament traits, and measures of internalizing and externalizing behaviors were also obtained on the boys. Although the groups did not differ during the lower demand task, SA + boys showed significantly greater motor activity than SA - boys during the tasks that required concerted effort, attention, and behavioral suppression. Multiple regression analysis indicated that under the low-demand condition, the presence of an anxiety disorder in the boy was the only significant predictor of activity level. However, under the conditions that demanded effort, concerted attention and behavioral suppression, SA + group membership, and having low rhythmicity (as a temperament trait) predicted heightened activity. Statistically controlling for rhythmicity, the SA + boys were estimated to have about 24% higher activity than control boys. The results suggest that heightened motor activity may be associated with susceptibility to substance abuse.

Mutual Dissatisfaction Between Mother and Son in Substance-Abusing and Normal Families

This study compares relationship satisfaction between mother and son in families where the father either qualified for a diagnosis of psychoactive substance use disorder (SA+) or had no lifetime psychiatric diagnosis (SA-). The authors found that there was greater mutual dissatisfaction in SA+ families compared with SA- families. The magnitude of dissatisfaction cov-aried with behavioral disturbance in the children; however, in SA+ families, mother-son dissatisfaction correlated positively with externalizing and internalizing behaviors in the children, whereas in SA- families dissatisfaction correlated only with externalizing behaviors. The results suggest that in SA+families, generalized behavioral deviations in the child, combined with parent-offspring dissatisfaction, may facilitate the childs disengagement from parental influence and promote negative association with peers.