Behavioral disinhibition and the development of substance-use disorders: Findings from the Minnesota Twin Family Study

Abstract

One variant of substance-use disorder is characterized by behavioral disinhibition. In this report, we martial evidence for a model for the development of this variant. We hypothesize that genetic liability for this variant is reflected in a spectrum of risk indicators linked to the inability or unwillingness to inhibit behavioral impulses. Included in this spectrum are personality traits suggesting low constraint, and externalizing psychopathology, including conduct, oppositional defiant, and attention-deficit disorder in children and antisocial personality disorder and behavior in adults. We further hypothesize that these individual differences in behavioral disinhibition are manifestations of underlying central nervous system processes associated with various psychophysiological anomalies, some of which may index genetic risk for substance abuse. Support for the model is derived from the analysis of findings from the Minnesota Twin Family Study, an epidemiological investigation of approximately 2,700 adolescent twins and their parents.

Differential parent-child relationships and adolescent externalizing symptoms: Cross-lagged analyses within a monozygotic twin differences design.

“…Participating families were broadly representative of the Minnesota population at the time the twins were born; approximately 98% are Caucasian. Further information regarding the design, recruitment procedures, participation rates, and zygosity determination procedures of the MTFS can be obtained elsewhere (Iacono, Carlson, Taylor, Elkins, & McGue, 1999).…”

Externalizing proneness and brain response during pre-cuing and viewing of emotional pictures

“…The perspective here is that heightened reactivity of this system is associated with difficulties in processing of emotional cues in dynamic situational contexts, leading to affective dysregulation expressed as distress, anger and reactive aggression (Blair, 2013;Blair et al, 2014). Elsewhere, Iacono et al (1999) demonstrated heightened physiological (electrodermal) reactivity to aversive noise blasts among highdisinhibited participants in a condition in which the blasts were signaled and thus predictable. 2 Whereas low-disinhibited participants were able to use the predictive signal to down-regulate their responses to the succeeding noise blasts, high-disinhibited subjects were not-reacting at increased levels to the blasts.…”

“…ii. If trait disinhibition primarily reflects overresponsiveness to threat (Blair et al, 2014) as related to impaired preparatory processing (Iacono et al, 1999) (Bechara et al, 2000;Davidson et al, 2000), and research has shown that electrodermal and fMRI responses covary (Critchley et al, 2000) and that this covariation occurs in differing task contexts, including resting state measurement (Patterson et al, 2002).…”

The adolescent origins of substance use disorders

“…The MTFS sample was identified from birth records from the US state of Minnesota and is broadly representative of families with twins born in that state. A complete description of the recruitment of the MTFS sample as well as evidence of sample representativeness is given in Iacono et al (1999). The MTFS samples have been followed longitudinally every 3-4 years, with in-person follow-up assessments timed to coincide with major life transitions in the life of American adolescents and young adults (Figure 1).…”

“…Diagnoses and symptom counts according to DSM-III-R, the diagnostic standard current at the time the MTFS was started, are generated by computer algorithm. The reliability of this consensus process for the diagnoses we assess is uniformly high (Iacono et al, 1999). …”