Shannon K. McWilliams

Reduced cortical gray matter volume in male adolescents with substance and conduct problems

UNLABELLED Boys with serious conduct and substance problems (Antisocial Substance Dependence (ASD)) repeatedly make impulsive and risky decisions in spite of possible negative consequences. Because prefrontal cortex (PFC) is involved in planning behavior in accord with prior rewards and punishments, structural abnormalities in PFC could contribute to a persons propensity to make risky decisions. METHODS We acquired high-resolution structural images of 25 male ASD patients (ages 14-18 years) and 19 controls of similar ages using a 3T MR system. We conducted whole-brain voxel-based morphometric analysis (p<0.05, corrected for multiple comparisons at whole-brain cluster-level) using Statistical Parametric Mapping version-5 and tested group differences in regional gray matter (GM) volume with analyses of covariance, adjusting for total GM volume, age, and IQ; we further adjusted between-group analyses for ADHD and depression. As secondary analyses, we tested for negative associations between GM volume and impulsivity within groups and separately, GM volume and symptom severity within patients using whole-brain regression analyses. RESULTS ASD boys had significantly lower GM volume than controls in left dorsolateral PFC (DLPFC), right lingual gyrus and bilateral cerebellum, and significantly higher GM volume in right precuneus. Left DLPFC GM volume showed negative association with impulsivity within controls and negative association with substance dependence severity within patients. CONCLUSIONS ASD boys show reduced GM volumes in several regions including DLPFC, a region highly relevant to impulsivity, disinhibition, and decision-making, and cerebellum, a region important for behavioral regulation, while they showed increased GM in precuneus, a region associated with self-referential and self-centered thinking.

Female Adolescents with Severe Substance and Conduct Problems Have Substantially Less Brain Gray Matter Volume

Objective Structural neuroimaging studies have demonstrated lower regional gray matter volume in adolescents with severe substance and conduct problems. These research studies, including ours, have generally focused on male-only or mixed-sex samples of adolescents with conduct and/or substance problems. Here we compare gray matter volume between female adolescents with severe substance and conduct problems and female healthy controls of similar ages. Hypotheses: Female adolescents with severe substance and conduct problems will show significantly less gray matter volume in frontal regions critical to inhibition (i.e. dorsolateral prefrontal cortex and ventrolateral prefrontal cortex), conflict processing (i.e., anterior cingulate), valuation of expected outcomes (i.e., medial orbitofrontal cortex) and the dopamine reward system (i.e. striatum). Methods We conducted whole-brain voxel-based morphometric comparison of structural MR images of 22 patients (14-18 years) with severe substance and conduct problems and 21 controls of similar age using statistical parametric mapping (SPM) and voxel-based morphometric (VBM8) toolbox. We tested group differences in regional gray matter volume with analyses of covariance, adjusting for age and IQ at p<0.05, corrected for multiple comparisons at whole-brain cluster-level threshold. Results Female adolescents with severe substance and conduct problems compared to controls showed significantly less gray matter volume in right dorsolateral prefrontal cortex, left ventrolateral prefrontal cortex, medial orbitofrontal cortex, anterior cingulate, bilateral somatosensory cortex, left supramarginal gyrus, and bilateral angular gyrus. Considering the entire brain, patients had 9.5% less overall gray matter volume compared to controls. Conclusions Female adolescents with severe substance and conduct problems in comparison to similarly aged female healthy controls showed substantially lower gray matter volume in brain regions involved in inhibition, conflict processing, valuation of outcomes, decision-making, reward, risk-taking, and rule-breaking antisocial behavior.

Brain cortical thickness in male adolescents with serious substance use and conduct problems

Abstract Background: Adolescents with substance use disorder (SUD) and conduct problems exhibit high levels of impulsivity and poor self-control. Limited work to date tests for brain cortical thickness differences in these youths. Objectives: To investigate differences in cortical thickness between adolescents with substance use and conduct problems and controls. Methods: We recruited 25 male adolescents with SUD, and 19 male adolescent controls, and completed structural 3T magnetic resonance brain imaging. Using the surface-based morphometry software FreeSurfer, we completed region-of-interest (ROI) analyses for group cortical thickness differences in left, and separately right, inferior frontal gyrus (IFG), orbitofrontal cortex (OFC) and insula. Using FreeSurfer, we completed whole-cerebrum analyses of group differences in cortical thickness. Results: Versus controls, the SUD group showed no cortical thickness differences in ROI analyses. Controlling for age and IQ, no regions with cortical thickness differences were found using whole-cerebrum analyses (though secondary analyses co-varying IQ and whole-cerebrum cortical thickness yielded a between-group cortical thickness difference in the left posterior cingulate/precuneus). Secondary findings showed that the SUD group, relative to controls, demonstrated significantly less right > left asymmetry in IFG, had weaker insular-to-whole-cerebrum cortical thickness correlations, and showed a positive association between conduct disorder symptom count and cortical thickness in a superior temporal gyrus cluster. Conclusion: Functional group differences may reflect a more nuanced cortical morphometric difference than ROI cortical thickness. Further investigation of morphometric differences is needed. If replicable findings can be established, they may aid in developing improved diagnostic or more targeted treatment approaches.

Adolescent Male Conduct-Disordered Patients in Substance Use Disorder Treatment: Examining the “Limited Prosocial Emotions” Specifier

ABSTRACT To our knowledge, this is the first study to examine the Diagnostic and Statistical Manual of Mental Disorders (DSM)-5-defined conduct disorder (CD) with limited prosocial emotions (LPE) among adolescents in substance use disorder (SUD) treatment, despite the high rates of CD in this population. We tested previously published methods of LPE categorization in a sample of male conduct-disordered patients in SUD treatment (N = 196). CD with LPE patients did not demonstrate a distinct pattern in terms of demographics or comorbidity regardless of the categorization method utilized. In conclusion, LPE, as operationalized here, does not identify a distinct subgroup of patients based on psychiatric comorbidity, SUD diagnoses, or demographics.

Adolescent perspectives on the return of individual results in genomic addiction research.

This study surveyed all adolescents who were enrolled in behavioral genomic research and provided DNA to a biobank, including 320 patients undergoing treatment for substance and conduct problems (SCPs) and 109 non-SCP controls. Participants selected from three options on the return of individual genomic results (RIR) and rated eight methods of re-contact. Most individuals with SCPs (77.8%) and non-SCP controls (72.5%) wanted RIR involving health or behavioral implications. The majority of individuals with SCPs (67.2%) and non-SCP controls (69.7%) indicated that phone re-contact was ‘best’, with e-mail (22.5% SCPs, 33.9% non-SCPs) and social networking websites (21.3% SCPs, 20.2% non-SCPs) being viable options. These results suggest a layered approach for RIR: phone calls, followed by e-mails and a secure message to a social networking account. Data from this special and vulnerable population, which includes youth involved in the criminal justice system and substantial minority participation, bring an essential and missing perspective to the discussion of RIR.

Imaging decision about whether to benefit self by harming others: Adolescents with conduct and substance problems, with or without callous-unemotionality, or developing typically ☆

We sought to identify brain activation differences in conduct-problem youth with limited prosocial emotions (LPE) compared to conduct-problem youth without LPE and community adolescents, and to test associations between brain activation and severity of callous-unemotional traits. We utilized a novel task, which asks subjects to repeatedly decide whether to accept offers where they will benefit but a beneficent other will be harmed. Behavior on this task has been previously associated with levels of prosocial emotions and severity of callous-unemotional traits, and is related to empathic concern. During fMRI acquisition, 66 male adolescents (21 conduct-problem patients with LPE, 21 without, and 24 typically-developing controls) played this novel game. Within typically-developing controls, we identified a network engaged during decision involving bilateral insula, and inferior parietal and medial frontal cortices, among other regions. Group comparisons using non-parametric (distribution-free) permutation tests demonstrated LPE patients had lower activation estimates than typically-developing adolescents in right anterior insula. Additional significant group differences emerged with our a priori parametric cluster-wise inference threshold. These results suggest measurable functional brain activation differences in conduct-problem adolescents with LPE compared to typically-developing adolescents. Such differences may underscore differential treatment needs for conduct-problem males with and without LPE.

Children’s brain activation during risky decision-making: A contributor to substance problems?

OBJECTIVE Among young children excessive externalizing behaviors often predict adolescent conduct and substance use disorders. Adolescents with those disorders show aberrant brain function when choosing between risky or cautious options. We therefore asked whether similarly aberrant brain function during risky decision-making accompanies excessive externalizing behaviors among children, hypothesizing an association between externalizing severity and regional intensity of brain activation during risky decision-making. METHOD Fifty-eight (58) 9-11 year-old children (both sexes), half community-recruited, half with substance-treated relatives, had parent-rated Child Behavior Checklist Externalizing scores. During fMRI, children repeatedly chose between doing a cautious behavior earning 1 point or a risky behavior that won 5 or lost 10 points. Conservative permutation-based whole-brain regression analyses sought brain regions where, during decision-making, activation significantly associated with externalizing score, with sex, and with their interaction. RESULTS Before risky responses higher externalizing scores were significantly, negatively associated with neural activation (ts: 2.91-4.76) in regions including medial prefrontal cortex (monitors environmental reward-punishment schedules), insula (monitors internal motivating states, e.g., hunger, anxiety), dopaminergic striatal and midbrain structures (anticipate and mediate reward), and cerebellum (where injuries actually induce externalizing behaviors). Before cautious responses there were no significant externalizing:activation associations (except in post hoc exploratory analyses), no significant sex differences in activation, and no significant sex-by-externalizing interactions. CONCLUSIONS Among children displaying more externalizing behaviors extensive decision-critical brain regions were hypoactive before risky behaviors. Such neural hypoactivity may contribute to the excessive real-life risky decisions that often produce externalizing behaviors. Substance exposure, minimal here, was a very unlikely cause.

Marijuana Use by Adolescents and Young Adults with Inflammatory Bowel Disease

Objective To evaluate marijuana use by adolescents and young adults with inflammatory bowel disease (IBD). Study design This descriptive cross‐sectional study of patients seen between December 2015 through June 2017 at Childrens Hospital Colorado for IBD enrolled patients 13‐23 years of age, independent of marijuana use status. Information obtained consisted of chart review, electronic and interview self‐report, and serum cannabinoid levels. Marijuana ever‐users were compared with never‐users for clinical characteristics and perceptions of risk with use; users provided information on routes, patterns, motivations, and perceived benefits and problems with use. Results Of 99 participants, ever‐use was endorsed by 32% (32 of 99) and daily or almost daily use by 9% (9 of 99). Older age was the only characteristic related to endorsing marijuana use. Twenty‐nine ever‐users completed all questionnaires. After adjusting for age, users were 10.7 times more likely to perceive low risk of harm with regular use (P < .001). At least 1 medical reason for use was endorsed by 57% (17 of 30), most commonly for relief of physical pain (53%, 16 of 30) (2 did not complete all questionnaires). Problems from use were identified by 37% (11 of 30), most commonly craving/strong urge to use. Most common route of use was smoking (83%) followed by edibles (50%), dabbing (40%), and vaping (30%). Conclusions Marijuana use by adolescents and young adults with IBD is common and perceived as beneficial. Guidelines for screening, testing, and counseling of marijuana use should be developed for patients with IBD.