Does Alcohol Initiation in Early-To-Middle Adolescence Predict Changes in Reward Motivation? Evidence of Sex Differences.

BACKGROUND: Reward motivation has been cross-sectionally correlated with adolescent alcohol use, but the temporal nature of this relationship remains unclear. This project sought to determine whether adolescent alcohol initiation longitudinally predicted changes in reward motivation and behavioral inhibition from early to middle adolescence, and explored the role of adolescent sex in this prediction. METHODS: A total of 180 11- to 14-year-olds were recruited and then followed for 3 years to age 14 to 17. Participants self-reported their alcohol use at all time points. We selected participants who were alcohol-naïve at Baseline (early adolescence) and then grouped them based on whether or not they reported alcohol initiation by Year 3 (Y3: middle adolescence). Adolescents completed self-report and experimental (delay discounting) measures of reward motivation and self-report measures of behavioral inhibition at Baseline and Y3. RESULTS: Adolescents' alcohol initiation significantly predicted higher Y3 self-reported reward motivation on one measure. Additionally, a significant sex × alcohol initiation interaction was found predicting Y3 task-based reward motivation (delay discounting), with boys' alcohol initiation predicting increased bias toward immediate reward at Y3. There was also a sex × alcohol initiation interaction predicting behavioral inhibition, with girls' alcohol initiation predicting higher behavioral inhibition at Y3. CONCLUSIONS: Results suggest that alcohol initiation among adolescents might precede changes in reward motivation, and the effects of alcohol on reward and behavioral inhibition may differ by adolescent sex.

Genetic Association and Expression Analyses of the Phosphatidylinositol-4-Phosphate 5-Kinase (PIP5K1C) Gene in Alcohol Use Disorder-Relevance for Pain Signaling and Alcohol Use.

BACKGROUND: The gene encoding phosphatidylinositol-4-phosphate 5-kinase (PIP5K1C) has been recently implicated in pain regulation. Interestingly, a recent cross-tissue and cross-phenotypic epigenetic analysis identified the same gene in alcohol use disorder (AUD). Given the high comorbidity between AUD and chronic pain, we hypothesized that genetic variation in PIP5K1C might contribute to susceptibility to AUD. METHODS: We conducted a case-control association study of genetic variants in PIP5K1C. Association analyses of 16 common PIP5K1C single nucleotide polymorphisms (SNPs) were conducted in cases and controls of African (427 cases and 137 controls) and European ancestry (488 cases and 324 controls) using standard methods. In addition, given the prominent role of the opioid system in pain signaling, we investigated the effects of acute alcohol exposure on PIP5K1C expression in humanized transgenic mice for the µ-opioid receptor that included the OPRM1 A118G polymorphism, a widely used mouse model to study analgesic response to opioids in pain. PIP5K1C expression was measured in the thalamus and basolateral amygdala (BLA) in mice after short-term administration (single 2 g/kg dose) of alcohol or saline using immunohistochemistry and analyzed by 2-way analysis of variance. RESULTS: In the case-control association study using an NIAAA discovery sample, 8 SNPs in PIP5K1C were significantly associated with AUD in the African ancestry (AA) group (p < 0.05 after correction; rs4807493, rs10405681, rs2074957, rs10432303, rs8109485, rs1476592, rs10419980, and rs4432372). However, a replication analysis using an independent sample (N = 3,801) found no significant associations after correction for multiple testing. In the humanized transgenic mouse model with the OPRM1 polymorphism, PIP5K1C expression was significantly different between alcohol and saline-treated mice, regardless of genotype, in both the thalamus (p < 0.05) and BLA (p < 0.01). CONCLUSIONS: Our discovery sample shows that genetic variants in PIP5K1C are associated with AUD in the AA group, and acute alcohol exposure leads to up-regulation of PIP5K1C, potentially explaining a mechanism underlying the increased risk for chronic pain conditions in individuals with AUD.

Association Analysis Between Genetic Variation in GATA Binding Protein 4 (GATA4) and Alcohol Use Disorder.

AIMS: Previous genetic association studies have shown that variation in the GATA4 gene encoding the GATA binding protein 4, a binding protein that binds to the ANA sequence GATA, increase susceptibility for alcohol use disorder (AUD). In this study, we aimed to replicate those findings in an independent sample and analyze their association with anxiety. METHODS: Overall, 1044 individuals with AUD [534 European American (EA), 510 African Americans (AA)] and 645 controls [413 EA, 232 AA] were genotyped using 34 markers. Genotype and allele frequencies were compared between cases and controls using chi-square analysis. Other phenotype data were analyzed for possible associations with GATA4 single-nucleotide polymorphisms (SNPs) in individuals with AUD. RESULTS: Rs6601604 was nominally significantly associated with AUD in EA, and 3 SNPs (rs6990313, rs11250159 and rs17153694) showed trend-level significance (P < 0.10) in AA. However, none of the SNPs were significant after correcting for multiple testing. Haplotype analysis of the 34 SNPs did not find a significant association between haplotype blocks and AUD diagnosis after correcting for multiple testing. From the phenotype analysis, anxiety was associated with GATA4 SNP rs10112596 among the AA group with AUD after a correction for multiple testing. CONCLUSIONS: Although previous studies have shown a relationship between variants of the GATA4 gene and a diagnosis of AUD, we did not replicate these findings in our sample. Additional studies of variation in this gene are needed to elucidate whether polymorphisms of the GATA4 gene are associated with AUD and other alcohol-related phenotypes. SHORT SUMMARY: GATA4 variants were not associated with AUD in either the European ancestry or African ancestry groups after correcting for multiple comparisons. Rs10112596 demonstrated a significant relationship with an anxiety measure among the African ancestry group with AUD.

Effects of Parenting Environment on Child and Adolescent Social-Emotional Brain Function.

The caregiving environment that children and adolescents experience is critically important for their social-emotional development. Parenting may affect child social-emotional outcomes through its effects in shaping the child's developing brain. Research has begun to investigate effects of parenting on child and adolescent brain function in humans using functional magnetic resonance imaging (fMRI). Here we review these initial studies. These studies find associations between parenting behavior and child and adolescent functional activation in neural networks involved in emotional arousal, emotion regulation (ER), reward processing, cognitive control, and social-emotional information processing. Findings from these studies suggest that higher negative parenting and lower positive parenting are generally associated with heightened activation in emotional arousal networks in response to negative emotional stimuli in youth. Further, findings indicate that lower positive parenting is associated with higher response in reward processing networks to monetary reward in youth. Finally, findings show that lower positive parenting predicts lower activation in cognitive control networks during cognitive control tasks and less adaptive neural responses to parent-specific stimuli. Several studies found these associations to be moderated by child sex or psychopathology risk status and we discuss these moderating factors and discuss implications of findings for children's social-emotional development.

Behavioral inhibition and approach tendencies are associated with striatal activation to loss: Implications for adolescent substance use.

Behavioral inhibition/avoidance and approach systems (BIS/BAS), which facilitate avoidance of aversive stimuli and approach of enticing stimuli, are thought to underlie engagement in substance use (SU). However, little is known about the neural correlates of these systems, particularly in adolescence. The current study examined associations between BIS/BAS tendencies and neural response to reward and loss and then examined whether there was an indirect effect of BIS/BAS on later SU initiation through these neural responses. 79 12-14 year olds underwent fMRI at baseline during a card guessing task. Adolescents reported on their BIS/BAS at baseline and on their SU at baseline and through a 3-year follow-up period. Results showed that higher BIS was associated with lower striatal activation and higher BAS with higher striatal activation to monetary loss. BIS and BAS were not associated with neural activation to monetary reward. There was no support that BIS or BAS predicted SU initiation through striatal activation to monetary loss. Overall, these results may suggest that adolescents with the tendency to avoid aversive stimuli assign less salience and adolescents with the tendency to approach enticing stimuli assign more salience to monetary loss.

Neural activation to loss and reward among alcohol naive adolescents who later initiate alcohol use.

Adolescent alcohol use is associated with adverse psychosocial outcomes, including an increased risk of alcohol use disorder in adulthood. It is therefore important to identify risk factors of alcohol initiation in adolescence. Research to date has shown that altered neural activation to reward is associated with alcohol use in adolescence; however, few studies have focused on neural activation to loss and alcohol use. The current study examined neural activation to loss and reward among 64 alcohol naive 12-14 year olds that did (n = 20) and did not initiate alcohol use by a three year follow-up period. Results showed that compared to adolescents that did not initiate alcohol use, adolescents that did initiate alcohol use by the three year follow-up period had increased activation to loss in the left striatum (i.e., putamen), right precuneus, and the brainstem/pons when they were alcohol naive at baseline. By contrast, alcohol initiation was not associated with neural activation to winning a reward. These results suggest that increased activation in brain regions implicated in salience, error detection/self-referential processing, and sensorimotor function, especially to negative outcomes, may represent an initial vulnerability factor for alcohol use in adolescence.

Effects of A Parenting-Focused Mindfulness Intervention on Adolescent Substance Use and Psychopathology: A Randomized Controlled Trial.

Substance use and psychopathology symptoms increase in adolescence. One key risk factor for these is high parent stress. Mindfulness interventions reduce stress in adults and may be useful to reduce parent stress and prevent substance use (SU) and psychopathology in adolescents. This study tested the feasibility and effects of a mindfulness intervention for parents on adolescent SU and psychopathology symptoms. Ninety-six mothers of 11-17 year olds were randomly assigned to a mindfulness intervention for parents (the Parenting Mindfully [PM] intervention) or a brief parent education [PE] control group. At pre-intervention, post-intervention, 6-month follow-up, and 1-year follow-up, adolescents reported on SU and mothers and adolescents reported on adolescent externalizing and internalizing symptoms. Primary intent to treat analyses found that the PM intervention prevented increases in adolescent SU over time, relative to the PE control group. The PM intervention also prevented increases in mother-reported externalizing symptoms over time relative to the PE control group. However, PM did not have a significant effect on internalizing symptoms. PM had an indirect effect on adolescent-reported externalizing symptoms through greater mother mindfulness levels at post-intervention, suggesting mother mindfulness as a potential intervention mechanism. Notably, while mothers reported high satisfaction with PM, intervention attendance was low (31% of mothers attended zero sessions). Secondary analyses with mothers who attended > = 50% of the interventions (n = 48) found significant PM effects on externalizing symptoms, but not SU. Overall, findings support mindfulness training for parents as a promising intervention and future studies should work to promote accessibility for stressed parents.Clinical Trials Identifier: NCT02038231; Date of Registration: January 13, 2014.

Association of High-Intensity Binge Drinking With Lipid and Liver Function Enzyme Levels.

Importance: The prevalence of high-intensity binge drinking (HIBD), defined as consuming 2 or more times the binge threshold defined by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), is rapidly increasing in the United States. While the relationship between alcohol consumption and lipid and liver function enzyme (LFT) biomarkers has been previously examined, the associations of HIBD with those biomarkers remain unknown. Objective: To examine associations of HIBD with lipid and LFT levels in a cross-sectional sample enriched with participants who engage in HIBD. Design, Setting, and Participants: Cross-sectional study using data from the NIAAA clinical sample collected from March 3, 2005, to August 21, 2017, with participants recruited for either the NIAAA screening protocols or inpatient alcohol treatment program. For this study, participants were stratified by self-reported alcohol consumption into 4 sex-specific binge levels: nonbinge and 1, 2, and 3 or more times the binge threshold (levels I, II, and III). Multivariable analyses examined the odds of clinically high levels of lipids and LFTs across binge levels. Analyses were performed from December 3, 2018, to January 30, 2019. Main Outcomes and Measures: Serum levels of high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, total cholesterol, triglycerides, alanine aminotransferase, aspartate aminotransferase, and γ-glutamyltransferase. Results: A total of 2065 participants underwent protocol screening; 1519 with data available on alcohol consumption, body mass index, lipid levels, and LFT levels were included in the final analyses. Mean (SD) age was 39.7 (12.1) years; mean (SD) body mass index was 26.6 (5.1); 978 (64.4%) were male; 718 (47.3%) were white; and 578 (31.1%) consumed alcohol at the nonbinge level, 321 (21.2%) at level I, 239 (15.7%) at level II, and 318 (25.1%) at level III. High-intensity binge drinking was associated with 2- to 8-fold increased odds for clinically high levels of HDL-C, total cholesterol, triglycerides, and all LFTs (eg, for HDL-C: level III odds ratio [OR], 8.65; 95% CI, 4.75-15.77 and for γ-glutamyltransferase: level III OR, 8.21; 95% CI, 5.90-11.43). Increased HIBD frequency (days consuming at levels II and III) was associated with increased odds for clinically high levels of HDL-C, total cholesterol, and all LFTs (per unit increase in days consuming at the respective binge level) (eg, for HDL-C: level II OR, 1.025; 95% CI, 1.014-1.036 and level III OR, 1.033; 95% CI, 1.019-1.047 and for γ-glutamyltransferase: level II OR, 1.028; 95% CI, 1.019-1.037 and level III OR, 1.033; 95% CI, 1.019-1.047). Conclusions and Relevance: High-impact binge drinking was significantly associated with increased odds for clinically high levels of lipids and LFTs. Given that HIBD is increasingly common among US adults, targeted interventions aimed at reducing HIBD may have important health benefits.