Striatal dopamine D2 receptor availability as a predictor of subsequent alcohol use in social drinkers.

BACKGROUND AND AIMS: Whereas striatal dopamine D2 receptor (D2R) availability has shown to be altered in individuals with alcohol use disorder (AUD) and in healthy individuals with a family history of AUD, the role of D2R in the development of AUD is unknown. In this positron emission tomography (PET) study, we measured whether D2R availability is associated with subsequent alcohol use and alcohol-related factors, at a follow-up 8 to 16 years post-PET scan, in social drinkers. DESIGN: Longitudinal study investigating the association between PET data and later self-report measures in healthy individuals. SETTING: Academic research imaging centre in Stockholm, Sweden. PARTICIPANTS: There were 71 individuals (68 of whom had evaluable PET data, 5 females, 42.0 years mean age) from a series of previous PET studies. MEASUREMENTS: One PET examination with the D2R antagonist radioligand [11 C]raclopride at baseline and self-report measures assessing alcohol use, drug use, impulsivity, reward sensitivity and family history of alcohol or substance use disorder at follow-up. FINDINGS: We found no evidence for an association between D2R availability and later alcohol use (B = -0.019, B 95% CI = -0.043 to -0.006, P = 0.147) nor for the majority of the alcohol-related factors (B 95% CI = -0.034 to 0.004, P = 0.273-0.288). A negative association with a small effect size was found between D2R availability and later impulsivity (B = -0.017, B 95% CI = -0.034 to -0.001, P = 0.046). CONCLUSIONS: Low striatal dopamine D2 receptor availability may not be a strong predictor in the development of alcohol use disorder.

Emotion dysregulation across levels of substance use.

Emotion dysregulation has shown to be of importance in the onset and maintenance of psychiatric disorders, including substance use disorders. How difficulties in emotion regulation differ across levels of substance use, and whether these relations are influenced by co-occurring psychiatric disorders, is less clear. This study aimed to identify difficulties in emotion regulation across the spectrum of substance use and evaluate the influence of co-occurring psychiatric symptoms. Self-reported emotion regulation difficulties, substance use, and other psychiatric symptoms were assessed in one community sample (n = 843) and two inpatient clinics, with substance use disorder populations (n = 415). Data were merged and analyzed with regression models and correlations. Emotion dysregulation was distributed across different levels of substance use, and significantly associated with substance use severity and frequency. High substance use severity and frequency was significantly associated with high scores on the emotion dysregulation facet specifically involving difficulties controlling impulsive behaviors. Psychiatric symptoms did not significantly influence the association between substance use and emotion dysregulation. Results indicate an association between emotion dysregulation and the frequency and severity of substance use, and also suggest that difficulties controlling impulsive behaviors may be a potentially useful treatment target for individuals with substance dependence.