Disinhibition- A Neurobehavioral Trait Underlying the Relationship Between Social Anxiety & Alcohol Use

Introduction:

Social anxiety (SA), marked by fear of negative evaluation and social avoidance, and problematic alcohol use (AU) are prevalent and often comorbid. Previous findings demonstrate that co-occurring SA and AU may result in increased symptom severity, decreased likelihood of treatment-seeking, and overall poorer treatment outcomes (Buckner et al., 2008). Many conceptualizations of SA emphasize that socially anxious individuals are overtly shy and risk-avoidant, although there is substantial, yet less robust support for an additional subtype of socially anxious individuals—those with disinhibited personalities (Nicholls et al., 2014; Iacono et al., 1999). Research has yielded mixed findings regarding the relationship between SA and AU, which suggests that moderating influences of specific risk factors (e.g., neurobiological traits) may help determine predispositions to developing psychopathology. One such neurobiological trait may be disinhibition, which can be defined as poor self-regulation (Mullins-Sweatt et al., 2019). Elevations in some facets of disinhibition (e.g., high impulsivity, risk-taking) may provide a way to escape anxious feelings and acute self-awareness, thus serving as a potential risk factor for AU (Kashdan & Hofmann, 2008). The presence of high rigid perfectionism and low impulsivity/risk-taking, in contrast, may yield over-regulated behaviors that protect against AU. 

Purpose:

The current study assesses the contribution of varying facets of disinhibition—impulsivity, risk-taking, and rigid perfectionism—in efforts to better understand the nature of the relationship between SA and dimensions of AU within different age groups.

Method: 

Data collected as part of the Social Processes and Mental Health (SPMH) Study were used to examine associations between facets of disinhibition, SA, and severity of AU. College-aged adults were split into two age groups: those below the legal drinking age (n = 295, 46.8% female; M_age = 18.8, SD = 0.755 years) and those above it (n = 164, 43.1% female; M_age = 24.1, SD = 4.9 years). A measure of social anxiety was created using self-report data from the Inventory of Depression and Anxiety-Expanded version (IDAS-II). Scores from the Personality Inventory for DSM-5 (PID-5) served as indices of impulsivity, risk-taking, and rigid perfectionism. Scores from the Michigan Alcoholism Screening Test (MAST) served as indices of alcohol use.

Results: 

At the bivariate level, SA was strongly positively associated with all three facets of disinhibition in the younger age group. SA was moderately associated with impulsivity and rigid perfectionism, but not risk-taking, in the older age group. For the younger age group, impulsivity and risk-taking were strongly, positively associated with dimensional AU, whereas for the older age group, impulsivity was the only facet associated with dimensional AU, and it was weak. At the multivariate level across both age groups, all three facets of disinhibition emerged as independent predictors of dimensional alcohol use. SA did not emerge as an independent predictor of AU in either age group. None of the hypothesized interactions reached significance

Discussion:

Results of this study suggest that high trait disinhibition is an independent predictor of SA, which aligns with associations found in previous literature. Our findings suggest that SA should not be viewed as a contributor to patterns of alcohol use. Although the sample was split into two age groups, it is still overarchingly an undergraduate student sample, which likely may not accurately capture typical adult substance use patterns. Future studies on SA should continue to take into account neurobehavioral constructs (i.e., self-regulatory strength models) in efforts to better understand trait disinhibition. Operationalizing additional constructs (e.g. motivation, coping, expectancy strategies) would likely provide insight into disentangling the complex relationship between SA & AU.