Relationships Between the Nicotine Metabolite Ratio (NMR) and Laboratory Assessments of Smoking Reinforcement and Craving Among Adults in a Smoking Cessation Trial.

INTRODUCTION: People who metabolize nicotine more quickly are generally less successful at quitting smoking. However, the mechanisms that link individual differences in the nicotine metabolite ratio (NMR), a phenotypic biomarker of the rate of nicotine clearance, to smoking outcomes are unclear. We tested the hypotheses that higher NMR is associated with greater smoking reinforcement, general craving, and cue-induced cigarette craving in a treatment-seeking sample. METHODS: Participants were 252 adults who smoke cigarettes enrolled in a randomized controlled smoking cessation trial (NCT03262662) conducted in Buffalo, New York, USA. Participants completed the Choice Behavior Under Cued Conditions (CBUCC) paradigm, a laboratory choice procedure, ~1 week before the first cessation treatment visit, at which time a saliva sample was collected for NMR assessment. On each CBUCC trial, participants reported cigarette craving during cue presentation (cigarette, water) and spent $0.01-0.25 for a chance (5%-95%) to sample the cue (1 puff, sip), providing measures of smoking reinforcement (spending for cigarettes vs. water), general cigarette craving (averaged across cigarette and water cues), and cue-specific craving (cigarette craving during cigarette vs. water cues). RESULTS: As observed in prior work, the NMR was significantly higher among white and female participants. As expected, both spending and cigarette craving were significantly greater on cigarette compared to water trials. However, contrary to our hypotheses, higher NMR was not associated with greater smoking reinforcement, general craving, or cue-specific craving. CONCLUSIONS: The present data do not support that smoking reinforcement or craving are related to nicotine metabolism among individuals seeking to quit smoking. IMPLICATIONS: Though greater smoking reinforcement, general craving, and cue-specific craving are hypothesized to be linked to faster nicotine metabolism, there was no evidence of such relationships in the present sample of adults seeking to quit smoking. Further research, including replication and consideration of alternate hypotheses, is warranted to elucidate the mechanisms by which the NMR is related to smoking cessation.

Parent Alcohol Use and Problems in Children's Alcohol-Related Learning and Subsequent Alcohol Use.

Background: Alcohol cognitions can emerge early in life and have lasting associations with alcohol use behavior. Observational learning theories suggest that witnessing alcohol use and its consequences may be an important mechanism underlying early development of alcohol cognitions. Parents are among the earliest contributors to children's alcohol-related learning, although findings regarding the association of parental alcohol use and problems with children's alcohol-related beliefs and attitudes are considerably mixed. This study tested associations of parent alcohol use and problems with adolescent alcohol expectancies, motives, and subsequent alcohol use to help clarify this literature. Methods: Families (N = 227) comprising family alcohol use disorder cases and demographically matched controls were recruited as part of a longitudinal investigation on child development. Parents reported on their alcohol use and problems at seven assessments throughout the index adolescents' childhood, and adolescents reported on their own alcohol expectancies in 6th grade, alcohol motives in 8th grade, and alcohol use in 12th grade. Results: Father alcohol problems and mother alcohol use were linked to more positive and less negative child alcohol expectancies, respectively. However, these cognitions did not contribute unique variance in adolescent alcohol use after accounting for additional risks included in the model. Conclusions: Findings highlight the need for future research aimed at modeling broader and potentially indirect sources of parent influences on adolescent alcohol-related learning and subsequent drinking behavior.

Reciprocal associations between implicit attitudes and drinking in emerging adulthood.

BACKGROUND: Implicit alcohol attitudes are considered important in the etiology of drinking, and theory posits reciprocal associations between them. Research testing reciprocal associations between implicit attitudes (using the Implicit Association Task, IAT) and drinking is limited by a failure to consider multiple processes influencing performance on the IAT and to disaggregate within- and between-person effects. The current study addressed these limitations by using a diffusion model to analyze IAT data and Latent Curve Models with Structured Residuals to test reciprocal associations. METHODS: The sample included 314 emerging adults from the community (52% female; predominantly non-Hispanic Caucasian (76%) or African American (15%)) assessed annually for three years. Differences between IAT conditions in the drift rate parameter of the EZ-diffusion model (vΔ) were used as an alternative to traditional response-time-based indices from the IAT (d-scores). Differences in drift rate have been found to index implicit attitudes effectively. RESULTS: Within-person reciprocal associations were supported, but between-person associations were not. Positive implicit alcohol attitudes (vΔ) were prospectively associated with heavy drinking, which was positively associated with subsequent positive implicit alcohol attitudes. CONCLUSIONS: We found that positive implicit alcohol attitudes and heavy drinking reinforce each other in a negative cascade within individuals. The results highlight the importance of disaggregating within- and between-person prospective effects when testing dual process models and suggest that the diffusion model may be a fruitful approach to enhance the construct validity of IAT assessed implicit attitudes.

Computational modeling reveals strategic and developmental differences in the behavioral impact of reward across adolescence.

Studies of reward effects on behavior in adolescence typically rely on performance metrics that confound myriad cognitive and non-cognitive processes, making it challenging to determine which process is impacted by reward. The present longitudinal study applied the diffusion decision model to a reward task to isolate the influence of reward on response caution from influences of processing and motor speed. Participants completed three annual assessments from early to middle adolescence (N = 387, 55% female, Mage  = 12.1 at Wave 1; Mage  = 13.1 at Wave 2, Mage  = 14.1 at Wave 3) and three annual assessments in late adolescence (Mages  = 17.8, 18.9, 19.9). At each assessment, participants completed a two-choice reaction time task under conditions of no-reward and a block in which points were awarded for speeded accuracy. Reward reduced response caution at all waves, as expected, but had a greater impact as teens moved from early to middle adolescence. Simulations to identify optimal response caution showed that teens were overly cautious in early adolescence but became too focused on speed over accuracy by middle adolescence. By late adolescence, participants adopted response styles that maximized reward. Further, response style was associated with both internalizing and externalizing symptoms in early-to-middle adolescence, providing evidence for the construct validity of a diffusion model approach in this developmental period.

A Psychometric Evaluation of the Stanford Expectations of Treatment Scale (SETS) in the Context of a Smoking Cessation Trial.

INTRODUCTION: Although treatment outcome expectancies (TOEs) may influence clinical outcomes, TOEs are rarely reported in the smoking cessation literature, in part because of the lack of validated measures. Therefore, we conducted a psychometric evaluation of TOEs scores with the Stanford Expectations of Treatment Scale (SETS) in the context of a smoking cessation clinical trial. METHODS: Participants were 320 adults enrolled in a randomized controlled trial of extended versus standard pre-quit varenicline treatment for smoking cessation (clinicaltrials.gov ID: NCT03262662). Across an 8-week treatment period, we examined the nature and stability of the factor structure using confirmatory factor analysis (CFA), evaluated discriminant validity by examining correlations with abstinence self-efficacy and positive/negative affect (PA/NA), and assessed internal consistency and test-retest reliability of SETS scores. RESULTS: CFAs supported a 2-factor structure that was stable (ie, invariant) across weeks. Positive and negative TOEs were each reflected in three-item subscales that exhibited acceptable to excellent internal consistency (Cronbach's alphas ≥ .77). Positive and negative TOEs were modestly correlated with PA and NA (all |rs| <.27, p < .05). Positive TOEs, but not negative TOEs, were moderately correlated with abstinence self-efficacy (rs = .45 to .61, p < .01). Both positive and negative TOEs scores demonstrated moderate test-retest reliability between assessments (rs = .54 to .72). CONCLUSIONS: SETS scores generally reflect a valid and reliable assessment of positive and negative TOEs in a sample of adults enrolled in a smoking cessation trial. The SETS appears to be a reasonable option for assessing TOEs in future smoking treatment studies. IMPLICATIONS: Assessments of treatment outcome expectancies are rarely reported in the smoking cessation literature. The present results support the validity and reliability of the SETS scores among adults seeking treatment for their smoking behavior.

An examination of the joint effects of adolescent interpersonal styles and parenting styles on substance use.

The current study examined how parenting and adolescent interpersonal styles jointly influence youths' abilities to form close relationships - a central developmental milestone - yet avoid substance use, which predominantly occurs in the presence of peers. Nine annual waves from an adolescent sample (N = 387) were used to assess (a) combinations of interpersonal and parenting styles from early to middle adolescence using longitudinal latent profile analysis, (b) the validity of these profiles on indicators of adjustment, and (c) the relationships between the profiles and growth in substance use across adolescence as well as substance-related consequences in late adolescence. The results supported five distinct combinations of interpersonal and parenting styles, and validity analyses identified both risk and protective profiles. The protective profile submissive-communal interpersonal style + high-warmth-authoritative parenting style was associated with indicators of positive social adjustment (e.g., friendship quality, resistance to peer influence) as well as lower levels of substance use. Significant differences also emerged with respect to substance-related consequences. The findings of this study highlight how combinations of adolescent interpersonal style and parenting render adolescents more or less successful at navigating peer relationships while avoiding substance use behaviors.

Assessing Parent-Adolescent Substance Use Discussions Using the Continuous Assessment of Interpersonal Dynamics.

Assessing parent-child interactions is critical for understanding family dynamics, however tools available for capturing these dynamics are limited. The current study sought to examine the validity of the Continuous Assessment of Interpersonal Dynamics (CAID) for understanding the dynamics of parent-adolescent substance use discussions. Specifically, we examined how CAID parameters were related to indicators of parenting and substance use. Sixty-one parent-adolescent dyads (M adolescent age = 14.02, 57% female; M parent age = 46.40; 98% female) completed three 9-minute video-taped conflict, alcohol, and cannabis discussions as well as self-report measures of parenting (e.g., monitoring, psychological control) and substance use behaviors (e.g., intentions, use with parental permission). Interactions were coded using the CAID which provides continuous assessments of parent and adolescent warmth and dominance. Parental warmth, adolescent warmth, and dominance complementarity CAID parameters were positively associated with adaptive parenting and negatively associated with maladaptive parenting factors. Parental warmth in the cannabis discussion was negatively associated with the substance use and intentions factor. These findings support CAID as a reliable and valid assessment of interpersonal dynamics that characterize parent-adolescent substance use discussions and suggest that substance use conversations may be most effective when parents and adolescents act warmly throughout the discussion and exhibit dominance complementarity.

Alcohol-Specific Communication and Emerging Adult Offspring's Perceived Parental Approval and Drinking in the Context of Parent Alcohol Expectancies.

BACKGROUND: There are mixed findings in the literature regarding the association between parental alcohol communication and offspring alcohol use. To clarify this association, this study tested a prospective mediated moderation model in which the association between parental communication about the risks of alcohol use and emerging adult offspring drinking was mediated by offspring perceived parental approval of drinking. Parental alcohol expectancies and use were tested as moderators of the link between communication and perceived approval. METHOD: The community sample of 378 emerging adult and caregiver dyads completed 3 annual assessments (first assessment mean age = 19.13). The sample was 54% female and majority White/non-Hispanic (76%). Caregivers reported on their own alcohol expectancies and use, and emerging adult offspring reported on parental communication of alcohol risks, perceived parental approval of drinking, and their own alcohol use. Multilevel modeling was used to test hypotheses. RESULTS: Mediated moderation was largely supported. More frequent communication about the risks of drinking was prospectively associated with low levels of perceived parental approval of alcohol use, which in turn was associated with low levels of offspring drinking. This pathway depended on parental alcohol expectancies. CONCLUSIONS: Findings suggest that including mediators (e.g., perceived approval of drinking) helps to clarify the mixed literature on parental communication about alcohol and that parental attitudes about alcohol can impact the effectiveness with which parents convey the risk of alcohol to offspring.

An examination of reciprocal associations between substance use and effortful control across adolescence using a bifactor model of externalizing symptoms.

Early adolescence is thought to represent a window of vulnerability when exposure to substances is particularly harmful, partly because the neurotoxic effects of adolescent substance use may derail self-regulation development. However, previous studies fail to account for externalizing symptoms, such as aggression and delinquency, that accompany adolescent substance use and may also derail the development of self-regulation. The current study aims to clarify whether the neurotoxic effects of adolescent substance use are associated with deficits in effortful control (EC) after accounting for externalizing symptoms and to examine reciprocal relationships between EC, externalizing symptoms, and substance use. A longitudinal sample of adolescents (N = 387) was used to estimate bifactor models of externalizing symptoms across five assessments (Mage = 11.6 to 19.9). The broad general externalizing factors were prospectively associated with declines in EC across adolescence and emerging adulthood. However, the narrow substance use specific factors were not prospectively associated with EC. Findings suggest that the broader externalizing context, but not the specific neurotoxic effects of substance use, may hamper self-regulation development. It is critical to account for the hierarchical structure of psychopathology, namely externalizing symptoms, when considering development of EC.

Testing alternative cascades from internalizing and externalizing symptoms to adolescent alcohol use and alcohol use disorder through co-occurring symptoms and peer delinquency.

Given the equivocal literature on the relationship between internalizing symptoms and early adolescent alcohol use (AU) and AU disorder (AUD), the present study took a developmental perspective to understand how internalizing and externalizing symptoms may operate together in the etiology of AU and AUD. We pit the delayed onset and rapid escalation hypothesis (Hussong et al., 2011) against a synthesis of the dual failure model and the stable co-occurring hypothesis (Capaldi, 1992; Colder et al., 2013, 2018) to test competing developmental pathways to adolescent AU and AUD involving problem behavior, peer delinquency, and early initiation of AU. A latent transactional and mediational framework was used to test pathways to AUD spanning developmental periods before AU initiation (Mage = 11) to early and high risk for AUD (Mage = 14-15 and Mage = 17-18). The results supported three pathways to AUD. The first started with "pure" externalizing symptoms in early childhood and involved multiple mediators, including the subsequent development of co-occurring symptoms and peer delinquency. The second pathway involved stable co-occurring symptoms. Interestingly, chronically elevated pure internalizing symptoms did not figure prominently in pathways to AUD. Selection and socialization effects between early AU and peer delinquency constituted a third pathway.

Agency, communion, and pubertal status: Separating between- and within-person associations to examine social goals development.

OBJECTIVES: Agentic (status/independence) and communal (acceptance/connectedness) social goals are thought to shape how adolescents transact with their social environments. Despite their theoretical importance, little work has focused on the development of these higher order personality dimensions. Informed by developmental neuroscience and evolutionary psychology theoretical frameworks, the current study examined associations between pubertal status, a person's level of pubertal development at a single point in time, and agentic and communal social goals across early to middle adolescence. METHODS: This longitudinal study consisted of 387 (55% female) adolescents (Wave 1 M age = 12.1) who were assessed annually across three waves. Hierarchical linear modeling was used to examine growth in pubertal status and agentic and communal goals and to distinguish between- and within-person associations between pubertal status and social goals. RESULTS: Within-person pubertal status was concurrently associated with higher levels of agentic and communal goals. In the cross-sectional and longitudinal models, between-person pubertal status was associated with higher levels of agentic social goals. No support was found for social goals prospectively predicting pubertal status. CONCLUSIONS: These findings provide support for the hypothesis that puberty, in part, may drive developmental shifts in the value adolescents place on close peer relationships and obtaining status and independence.

Parents' Cannabis-Related Attitudes and Emerging Adult Offspring Cannabis Use: Testing the Mediating Effect of Perceived Parental Approval.

Background: Contrary to parental alcohol use and expectancies work, little is known about how parent's cannabis use (CU) and expectancies influence offspring CU. This is a notable gap in the literature given increasing acceptability and use of cannabis, especially among emerging adults (EA). Moreover, limited work has tested mechanisms of transmission of risk from these parent factors. This study addresses these gaps by testing prospective associations of parental CU and expectancies with offspring CU and CU problems, and perceived parental approval of offspring CU as a potential mediator. Method: A community sample of 314 EA and caregiver dyads completed three annual assessments (mean age = 19.13). The sample was 54% female and majority White/non-Hispanic (76%). Caregivers reported on their cannabis expectancies and use, and EA reported on their CU, CU-related problems, and perceived parental approval of CU. Results: Longitudinal structural equation modeling supported a mediated pathway such that high parental positive cannabis expectancies were associated with perceived parental approval of CU, which in turn, predicted increases in EA CU and CU problems. Parental negative expectancies had a significant indirect effect but in the opposite direction. Indirect effects were found above and beyond parental CU, which was not associated with offspring CU. Conclusions: This is the first study to test prospective indirect effects of parental cannabis expectancies on offspring CU. Findings suggest parents' attitudes, even in the absence of parental use, confer risk for offspring use by shaping perceived acceptance of CU, suggesting parental expectancies as targets for parent-based CU interventions.

Distress-Related Internalizing Symptoms Interact With Externalizing Symptoms to Predict Alcohol Problems in an Inpatient Adolescent Sample.

BACKGROUND AND OBJECTIVES: Previous research has yielded equivocal findings regarding whether internalizing symptoms are risk factors for adolescent hazardous alcohol use (AU), specifically in the presence of externalizing symptoms. This may be due to the type of internalizing symptoms examined (ie, distress vs fear), and the use of primarily normative rather than clinical samples. Thus, we tested internalizing and externalizing symptom interactions as they relate to adolescent hazardous AU in a high-risk, clinical sample of adolescents. METHODS: Adolescents (N = 101; 66% female; Mage = 15) were recruited from an inpatient psychiatric unit and assessed for current symptoms. Hypotheses were tested by running a series of moderation models regressing hazardous AU on a set of internalizing symptoms (ie, depression, generalized anxiety disorder [GAD], social anxiety, separation anxiety, school avoidance, and panic), each interacting with externalizing symptoms. RESULTS: We observed significant interactions between several internalizing symptoms (depression, GAD, and panic symptoms) and externalizing symptoms predicting hazardous AU. These internalizing symptoms were unrelated to AU at low and average levels of externalizing symptoms, but were positively related to AU at high levels of externalizing symptoms. DISCUSSION AND CONCLUSIONS: In this clinical sample, distress-related internalizing symptomatology was associated with risk for, and not protection against, hazardous AU, but only when accompanied by high externalizing symptoms. SCIENTIFIC SIGNIFICANCE: Findings suggest that whether or not internalizing symptoms operate synergistically with externalizing symptoms to predict hazardous AU depends on the subdomain of internalizing symptoms (distress vs fear) and perhaps the type of sample (ie, clinical vs community). (Am J Addict 2019:00:00-00).

Adolescent Social Norms and Alcohol Use: Separating Between- and Within-Person Associations to Test Reciprocal Determinism.

Despite perceived drinking norms being robust predictors of adolescent alcohol use, few studies have assessed the development of perceived norms across adolescence and processes accounting for the strong associations between perceived norms and drinking. Using reciprocal determinism as a theoretical basis for understanding the development of adolescent drinking norms, this study examined reciprocal associations across nine waves of data spanning early to late adolescence. Bivariate latent curve models with structured residuals demonstrated consistent within-person reciprocal associations between descriptive and injunctive norms and alcohol use after accounting for growth in norms and alcohol use. Results suggest the need for developmentally informed intervention efforts targeting perceived drinking norms during early and middle adolescence.

The effect of prenatal adversity on externalizing behaviors at 24 months of age in a high-risk sample: Maternal sensitivity as a moderator.

The purpose of this study was to examine the moderating role of maternal sensitivity on the association between prenatal adversity and externalizing behaviors at 24 months of age in a diverse, high-risk sample. We hypothesized that among children with higher prenatal adversity, high maternal sensitivity would serve as a protective factor. Participants were 247 primarily low-income, diverse dyads. Results indicated a significant interaction effect of maternal sensitivity and prenatal adversity on externalizing problems. The association between prenatal adversity and externalizing behaviors was significant only among children who experienced low prenatal adversity, with higher maternal sensitivity associated with lower externalizing behaviors. These findings indicate that, in the absence of high prenatal risk, responsive and sensitive parenting can buffer children in an otherwise high-risk sample from the development of externalizing behaviors.

El propósito de este estudio fue examinar el papel moderador que la sensibilidad materna tiene sobre la asociación entre adversidad prenatal y las conductas de externalización a los 24 meses de edad en un grupo muestra diverso y de alto riesgo. Nuestra hipótesis es que entre los niños con más alta adversidad prenatal (PA), una alta sensibilidad materna serviría como un factor de protección. Participaron 247 díadas diversas, primariamente de bajos recursos económicos (173 infantes expuestos a sustancias). Los resultados indicaron un significativo efecto de interacción de la sensibilidad materna y la adversidad prenatal sobre los problemas de externalización. La asociación entre la adversidad prenatal y las conductas de externalización fue significativa sólo entre niños que habían experimentado una adversidad prenatal baja, mientras que una más alta sensibilidad materna se asoció con más bajas conductas de externalización. Estos resultados indican que, en ausencia de un riesgo prenatal alto, una crianza receptiva y sensible puede amortiguar el desarrollo de conductas de externalización en niños que, de lo contrario, están dentro de un grupo muestra de alto riesgo.

Le but de cette étude était d'examiner le rôle modérateur de la sensibilité maternelle sur l'association entre l'adversité prénatale et les comportements d'externalisation à l'âge de 24 mois chez un échantillon varié, et à haut risque. Nous avons pris comme hypothèse que chez les enfants avec une adversité prénatale élevée (PA), une sensibilité maternelle élevée servirait de facteur de protection. Les participants ont consisté en 247 dyades diverse et principalement issues de milieux défavorisés (173 bébés exposés à la toxicomanie). Les résultats indiquent un effet d'interaction important de la sensibilité maternelle et de l'adversité prénatale sur les problèmes d'externalisation. Le lien entre l'adversité prénatale et les comportements d'externalisation n'était important que chez les enfants ayant fait l'expérience d'une adversité prénatale peu élevée, avec une sensibilité maternelle plus élevée liée à des comportements d'externalisation moins élevés. Ces résultats indiquent que, en l'absence d'une risque prénatal élevé, le parentage réactif et sensible peut servir de tampon aux enfants contre le développement de comportements d'externalisation dans un échantillon qui est par ailleurs à haut risque.

Trajectories of College Alcohol Involvement and Their Associations with Later Alcohol Use Disorder Symptoms.

Little is known about what differentiates individuals whose drinking patterns escalate into problematic use following the transition out of college compared to those who learn to drink in a way that is consistent with independent adult roles. Patterns of alcohol use and problems during college may pre-sage progression toward problem drinking in adulthood. The present study sought to examine such patterns in an effort to delineate those at greatest risk. Research has not yet elucidated whether, when, and how these groups diverge. Our results indicate that students who report AUD symptoms one year following graduation reported greater alcohol involvement from the first semester and escalated their involvement with alcohol at a more rapid pace. We observed marked and measurable differences in drinking patterns between those who go on to exhibit AUD symptoms following college and those who do not. A close inspection of these differences reveals that relatively small absolute differences in alcohol consumption add up to large differences in alcohol-related consequences. Thus, markers of longer-term risk are present early in college, and greater escalation of drinking across college is an indicator that intervention is needed. Brief Motivational Interventions could help students to anticipate some of the challenges ahead as they transition from the college environment, as well as the potential deleterious effects of immoderate alcohol use on making a successful transition into adult roles. In addition to the beginning of college, our findings also point to critical periods during which screening and brief intervention may be optimally timed.

The development of inhibitory control in adolescence and prospective relations with delinquency.

INTRODUCTION: Despite the central role of inhibitory control in models of adolescent development, few studies have examined the longitudinal development of inhibitory control within adolescence and its prospective association with maladaptive outcomes. The current study evaluated: 1) growth in inhibitory control from early- to middle-adolescence, and 2) the relation between inhibitory control and later delinquency. METHODS: Participants included 387 parent-child dyads (11-13 years old at Wave 1; 55% female; USA). Across three annual assessments, teens completed the Stop Signal Task (SST), and parents completed the Inhibitory Control subscale of the Early Adolescent Temperament Questionnaire-Revised. Teens self-reported their delinquent behaviors in early (Mage = 12.1) and middle adolescence (Mage = 14.1) and emerging adulthood (Mage = 18.2). RESULTS: Latent growth curve models indicated that SST performance improved curvilinearly from early to middle adolescence (ages 11-15), with growth slowing around middle adolescence. However, no growth in parent-reported inhibitory control was observed. Lower task-based and parent-reported inhibitory control in early adolescence predicted greater increases in delinquency from middle adolescence to emerging adulthood. However, rate of growth in task-based inhibitory control was unrelated to later delinquency. CONCLUSIONS: This longitudinal study provides a novel examination of the development of inhibitory control across early and middle adolescence. Results suggest that the degree to which inhibitory control confers risk for later delinquency may be captured in early adolescence, consistent with neurodevelopmental accounts of delinquency risk. Differences across assessment tools also highlight the need for careful measurement considerations in future work, as task-based measures may be better suited to capture within-person changes over time.

Dyadic and Group-Level Positive Friendship Characteristics and Susceptibility to Perceived Delinquent Peer Substance Use.

Peer relations researchers have suggested that dyadic and peer group relationship characteristics may interact with each other to affect behavior. Building on prior work that has pitted the relative effects of dyadic and peer group relationship characteristics on susceptibility to peer influence, the present study sought to integrate dyadic and group characteristics into a moderational model by testing whether friendship quality and peer group identification together exacerbate risk for conforming to peer norms for substance use. This longitudinal study included 387 early adolescents assessed annually for 4 years. Participants completed measures of perceived peer delinquency, friendship quality, peer group identification, and substance use frequency. Results indicated that perceived peer delinquency had the strongest association with substance use for adolescents characterized by high friendship quality and high peer group identification. These findings highlight the importance of considering the joint effects of multiple peer relationship characteristics on susceptibility to peer influence.

How do stimulant treatments for ADHD work? Evidence for mediation by improved cognition.

BACKGROUND: Stimulant medications such as methylphenidate (MPH) are the frontline treatment for Attention-Deficit/Hyperactivity Disorder (ADHD). Despite their well-documented efficacy, the mechanisms by which stimulants improve clinical outcomes are not clear. The current study evaluated whether MPH effects on classroom behavior were mediated by improved cognitive functioning. METHODS: Children with ADHD (n = 82; 9-12 years old) participated in a week-long summer research camp, consisting of cognitive testing, classroom periods, and recreational activities. After a baseline day, participants completed a 3-day randomized, double-blind, placebo-controlled trial of MPH (at doses approximating 0.3 and 0.6 mg/kg of immediate-release MPH dosed TID). Cognitive domains included inhibitory control (Stop Signal Task and prepulse inhibition of startle), attention (Continuous Performance Task and reaction time variability), and working memory (forward and backward spatial span). Clinical outcomes included math seatwork productivity and teacher-rated classroom behavior. A within-subjects path-analytic approach was used to test mediation. MPH-placebo and dose-response contrasts were used to evaluate drug effects. RESULTS: Methylphenidate improved seatwork productivity and teacher ratings (ds = 1.4 and 1.1) and all domains of cognition (ds = 0.3-1.1). Inhibitory control (Stop Signal Task, SST) and working memory backward uniquely mediated the effect of MPH (vs. placebo) on productivity. Only working memory backward mediated the impact of MPH on teacher-rated behavior. The dose-response (0.6 vs. 0.3 mg/kg) effects were more modest for clinical outcomes (ds = 0.4 and 0.2) and cognition (ds = 0-0.3); there was no evidence of cognitive mediation of the clinical dose-response effects. CONCLUSIONS: These findings are novel in demonstrating that specific cognitive processes mediate clinical improvement with stimulant treatment for ADHD. They converge with work on ADHD theory, neurobiology, and treatment development in suggesting that inhibitory control and working memory may be mechanisms of stimulant treatment response in ADHD. More work is necessary to evaluate the degree to which these findings generalize to chronic treatment, a broader array of clinical outcomes, and nonstimulant treatments.

Prenatal Risk and Infant Regulation: Indirect Pathways via Fetal Growth and Maternal Prenatal Stress and Anger.

Pathways from maternal tobacco, marijuana, stress, and anger in pregnancy to infant reactivity and regulation (RR) at 9 months of infant age were examined in a low-income, diverse sample beginning in the first trimester of pregnancy, with fetal growth and postnatal stress/anger as potential mediators, and infant sex as a moderator. Participants were 247 dyads (173 substance-exposed infants). There were no direct effects of prenatal risk on RR and no moderation by sex. However, there were significant indirect effects on RR via poor fetal growth and higher postnatal anger. The study adds to the sparse literature on joint effects of tobacco and marijuana, and highlights the role of fetal growth and maternal anger as important pathways from prenatal risk to infant RR.