Prospective study of the association between abandoned dwellings and testosterone level on the development of behaviors leading to cannabis use disorder in boys

Pubertal Testosterone and Brain Response to Faces in Young Adulthood: An Interplay between Organizational and Activational Effects in Young Men

According to the organizational-activational hypothesis, the organizational effects of testosterone during (prenatal) brain development moderate the activational effects of adult testosterone on behavior. Accumulating evidence supports the notion that adolescence is another period during which sex hormones organize the nervous system. Here we investigate how pubertal sex hormones moderate the activational effects of adult sex hormones on social cognition in humans. To do so, we recruited a sample of young men (n = 507; age, ∼19 years) from a longitudinal birth cohort and investigated whether testosterone exposure during adolescence (from 9 to 17 years of age) moderates the relation between current testosterone and brain response to faces in young adulthood, as assessed with functional magnetic resonance imaging (fMRI). Our results showed that the cumulative exposure to testosterone during adolescence moderated the relation between adult testosterone and both the mean fMRI response and functional connectivity (i.e., node strength). Specifically, in participants with low exposure to testosterone during puberty, we observed a positive relationship between current testosterone and the brain response to faces; this was not the case for participants with medium and high pubertal testosterone. Furthermore, we observed a stronger relationship between the brain response and current testosterone in parts of the angry-face network associated with (vs without) motion in the eye region of an observed (angry) face. We speculate that pubertal testosterone modulates the relationship between current testosterone and brain response to social cues carried by the eyes and signaling a potential threat.SIGNIFICANCE STATEMENT Accumulating evidence supports the organizational effects of pubertal testosterone, but the body of literature examining these effects on social cognition in humans is in its infancy. With a sample of young men from a longitudinal birth cohort, we showed that the cumulative exposure to testosterone during adolescence moderated the relation between adult testosterone and both the mean BOLD signal change and functional connectivity. Specifically, we observed a positive relationship between adult testosterone and the brain response to faces in participants with low exposure to testosterone during puberty, but not in participants with medium and high pubertal testosterone. Results of further analysis suggest that sensitivity to cues carried by the eyes might underlie the relationship between testosterone and brain response to faces, especially in the context of a potential threat.

Developmental trajectory classes in psychological dysregulation predict later decision-making competence

Adolescence and emerging adulthood are developmental periods associated with increased risk taking, including alcohol and substance use and antisocial behaviors. Typical psychological growth from adolescence into early adulthood reflects increases in traits related to psychological regulation (e.g., greater emotional stability and less impulsivity), which are typically considered protective factors against risk behaviors. However, individuals may vary greatly in their development of these characteristics. This study examines the degree to which heterogeneity in developmental trajectories of psychological regulation are associated with later performance on decision-making skills battery. In this study, psychological regulation was assessed at age 10-12, with follow-up assessments at 14, 16, and 19 years. At age 19, we administered the Youth Decision-Making Competence (DMC; Parker & Fischhoff, 2005) measure. Correlational analyses revealed that lower psychological regulation, as early as age 10, was associated with lower DMC scores. A latent class growth mixture model yielded three distinct developmental trajectory classes of psychological dysregulation: (a) a Moderate-Stable group, a modal class that demonstrated stable and average regulative tendencies throughout adolescence, (b) a Low-Decreasing group, which demonstrated greater self-regulation throughout childhood, and a (c) High-Increasing group, which demonstrated low self-regulative tendencies (higher dysregulation) at age 10 that became increasingly dysregulated throughout adolescence. Individuals in the High-Increasing group demonstrated lower DMC performance than those in the Moderate-Stable and Low-Decreasing groups. Our findings also reinforce past work that indicates considerable individual differences in intra-individual change across adolescence, and that early patterns of psychological dysregulation development can impact later decision-making tendencies.

Perceived neighborhood disorder and frequency of marijuana use among emerging adult African American females

Emerging adult African American females are at increased risk for cannabis use disorders. Ecological models suggest that African Americans' increased risk for substance use disorders and associated adverse outcomes may result from chronic exposure to contextual disadvantages, such as living in economically deprived and disorganized communities. However levels of vulnerability for developing cannabis use disorders vary, even among residents of disadvantaged neighborhoods. Therefore, studies focused on within group differences are necessary. This study examined the relationship between frequency of marijuana use and perceived neighborhood disorder. The sample included 117 African American emerging adult females (M_age = 23.6 ± 3.4). After providing informed consent, participants completed a semi-structured interview that included the Neighborhood Environment Scale and a self-report measure of marijuana use. Additionally, participants provided a urine sample that was tested for the presence of psychoactive drugs. 46% tested positive for marijuana and 45% reported using marijuana in the past 30 days. 27% reported frequent/heavy use. Results from multinomial logistic regression analysis indicated a significant relationship between perceived neighborhood disorder and heavy marijuana use (AOR = 3.3; 95% CI = 1.06 - 10.29). Findings suggest African American emerging adult female residents of economically disadvantaged neighborhoods who appraise their environments as disorganized may be at heighten risk for problematic marijuana use and should be targeted for intervention. Moreover, the findings support the need for multi-systems interventions. As policy makers consider the legalization of marijuana, it is important that differences in marijuana use behaviors and negative outcomes across groups and contexts are taken into consideration.

Risk for Substance Use Disorders in young adulthood: Associations with developmental experiences of homelessness, foster care, and adverse childhood experiences

BACKGROUND

Multiple developmental risk factors for Substance Use Disorders (SUDs) during young adulthood have been identified. In this investigation, we examined the impact of homelessness, foster care, and adverse childhood experiences (ACEs) prior to 12th grade on the development of three common SUDs during young adulthood-Alcohol Use Disorder (AUD), Tobacco Use Disorder (TUD) and Cannabis Use Disorder (CUD). Our hypothesis was that while both homelessness and ACEs are significant risk factors for young adult SUDs, foster care involvement might convey protection.

METHODS

Using nationally representative data from the National Longitudinal Study of Adolescent to Adult Health, measures of ACEs were derived from the CDC-Kaiser ACE study, and DSM-V SUD diagnoses were derived from items originally based on DSM-IV. SUD diagnoses were binned into "mild", "moderate", and "severe" groupings. Survey-based logistic models were used to estimate risks of SUDs while controlling for demographics.

RESULTS

The results suggest that the experience of homelessness prior to 12th grade in addition to ACEs were significantly associated with the development in young adulthood of the most severe forms of AUD and TUD and all severity levels of CUD. Foster care was not associated with either risk or protection from SUDs.

CONCLUSIONS

The experience of homelessness during development may be viewed as another detrimental ACE that is a risk factor for the most common SUDs in young adulthood. Given the magnitude of the current epidemic of homelessness in the U.S., these results should raise substantial concern.

The Impact of the Urban Neighborhood Environment on Marijuana Trajectories During Emerging Adulthood

Although there is little difference in rates of marijuana use between White and Black youth, Blacks have significantly higher rates of marijuana use and disorder in young adulthood. Theory suggests that factors tied to social disadvantage may explain this disparity, and neighborhood setting may be a key exposure. This study sought to identify trajectories of marijuana use in an urban sample during emerging adulthood, neighborhood contexts that predict these trajectories and social role transitions or "turning points" that may redirect them. Data are from a longitudinal cohort study of 378 primarily Black emerging adults who were first sampled in childhood based on their residence in low-income neighborhoods in Baltimore City and followed up annually. Group-based trajectory modeling identified three groups: No Use (68.8%), Declining Use (19.6%), and Chronic Use (11.7%). Living in close proximity to an alcohol outlet, and living in a neighborhood with more female-headed households and higher rates of violent crime increased the odds of membership in the Chronic Use group relative to No Use. Living in a neighborhood with more positive social activity increased the odds of membership in the Declining Use group relative to No Use. Not receiving a high school diploma or GED, pregnancy, and parenting also increased the odds of membership in the Declining Use group relative to No Use. These findings provide support that minority youth living in socially toxic and disordered neighborhoods are at increased risk of continuing on a trajectory of marijuana use during emerging adulthood while positive social activity in neighborhoods has the potential to redirect these negative trajectories. Besides taking on the responsibilities of parenting, emerging adults in the marijuana user groups had similar educational and family outcomes, suggesting that early marijuana use may have long-term implications.

Age of First Marijuana Use and Its Impact on Education Attainment and Employment Status

With the increased prevalence of marijuana use among youth, the increase in state legalization, and changing social norms in the United States, it is important to understand the long-term impact of marijuana use initiation. This study examined whether age of first marijuana use is associated with educational attainment and employment status. Data from 5,988 adults aged 26 to 49 years who participated in the 2015 National Survey on Drug Use and Health were used in the current study. Logistic regression analyses were used to examine the odds of graduating from high school and being employed. Controlling for demographics, persons with late-early first use had significantly higher odds of graduating from high school and being employed compared with persons with early first use. Results underscore the importance of early prevention for youth aged 15 and younger and have implications for intervention and policy development.

Neighborhood context and transitions in marijuana use among urban young adults

BACKGROUND

In emerging adulthood when many youth are maturing out of marijuana use, Blacks continue to have high rates of use and disorder. Theory suggests that factors tied to neighborhood disadvantage may partially explain this phenomenon but research is limited.

OBJECTIVES

This study examines the influence of neighborhood physical and social disorder on transitions in marijuana use during emerging adulthood in a low-income urban sample.

METHODS

379 primarily Black young adults residing in low-income neighborhoods in Baltimore City were followed-up annually from ages 18 to 21. Neighborhood environment was evaluated using a valid and reliable field-rater assessment of the residential block. Longitudinal latent class and latent transition analyses were performed.

RESULTS

Fit indices supported three-classes of marijuana use: no use, infrequent use and frequent use. Between ages 18 and 21, young adults tended to transition toward lower levels of use. However, neighborhood physical disorder was associated with transitioning to increased marijuana use (no use to frequent use; AOR = 2.712; p = .023) while positive neighborhood social activity was associated with a decreased risk (AOR = 0.002; p = .013). Neighborhood social activity was also associated with decreases in use (frequent to infrequent use; AOR = 2.342; p = .020). Conclusions/Importance: These findings demonstrate that physical disorder within the context of a low-income urban neighborhood adversely impacts marijuana use. However, even in the presence of physical disorder, interventions that foster collective efficacy among residents through positive social activity may prevent initiation and progression of marijuana use.

Brain circuitry associated with the development of substance use in bipolar disorder and preliminary evidence for sexual dimorphism in adolescents

Substance use disorders and mood disorders are highly comorbid and confer a high risk for adverse outcomes. However, data are limited on the neurodevelopmental basis of this comorbidity. Substance use initiation typically occurs during adolescence, and sex-specific developmental mechanisms are implicated. In this preliminary study, we review the literature and investigate regional gray matter volume (GMV) associated with subsequent substance use problems in adolescents with bipolar disorder (BD) and explore these associations for females and males. Thirty adolescents with DSM-IV-diagnosed BD and minimal alcohol/substance exposure completed baseline structural magnetic resonance imaging scans. At follow-up (on average 6 years post baseline), subjects were administered the CRAFFT interview and categorized into those scoring at high ( ≥ 2: CRAFFT_HIGH ) vs. low ( < 2: CRAFFT_LOW ) risk for alcohol/substance problems. Lower GMV in prefrontal, insular, and temporopolar cortices were observed at baseline among adolescents with BD reporting subsequent alcohol and cannabis use compared to adolescents with BD who did not (P < 0.005, clusters ≥ 20 voxels). Lower dorsolateral prefrontal GMV was associated with future substance use in both females and males. In females, lower orbitofrontal and insula GMV was associated with future substance use, while in males, lower rostral prefrontal GMV was associated with future use. Lower orbitofrontal, insular, and temporopolar GMV was observed in those who transitioned to smoking tobacco. Findings indicate that GMV development is associated with risk for future substance use problems in adolescents with BD, with results implicating GMV development in regions subserving emotional regulation in females and regions subserving executive processes and attention in males. © 2016 Wiley Periodicals, Inc.

Individual, peer, and family factor modification of neighborhood-level effects on adolescent alcohol, cigarette, e-cigarette, and marijuana use

BACKGROUND

Neighborhood factors reported subjectively by residents and measured objectively at the census tract are both associated with adolescent alcohol, tobacco (cigarette and electronic cigarette), and other drug (marijuana) (ATOD) use. Less clear is how these neighborhood factors are longitudinally associated with each substance. Equivocal findings may be due to lack of consideration of individual, peer, and family effect modifiers, which could help adolescents overcome exposure to stressful neighborhood environments.

METHODS

We used multivariate logistic regressions with interaction terms to test whether parental monitoring, resistance self-efficacy (RSE) and being around peers who use ATOD modified the association between four subjective and objective neighborhood measures and odds of using each substance measured one year later among 2539 high school students and college freshmen originally recruited from middle schools in Southern California.

RESULTS

Census tract-level disadvantage was not longitudinally associated with ATOD use. However, perceptions of higher neighborhood disorganization, less social cohesion, and more neighborhood problems with alcohol and drug use were associated with higher odds of ATOD use. Higher RSE and weaker affiliations with peers who use ATOD consistently buffered negative effects of neighborhood disorganization and neighborhood problems with alcohol and drugs on past year ATOD use.

CONCLUSIONS

Community-level programs that increase social cohesion among neighbors, neighborhood monitoring of deviant behaviors, and better policing of open drug selling may prevent ATOD use. Programs should also target RSE and minimize affiliations with peers who use ATOD, which could reduce the magnitude of the association with ATOD, even for adolescents living in the most at-risk neighborhoods.

Longitudinal Studies on the Etiology of Cannabis Use Disorder: A Review

PURPOSE OF REVIEW

This review summarizes the literature to date that has capitalized on the longitudinal research study framework in order to elucidate the etiology of cannabis use disorders (CUDs).

RECENT FINDINGS

The studies are mixed with respect to reliable predictors of CUD development. Of the studies outlined, the most consistently indicated risk factors for CUD development include: male sex, past cannabis and other substance use (especially tobacco), and the presence of pre/comorbid psychopathology (especially mood disorders). Social motives and peer involvement may also play a role in this transition. Many of these CUD risk factors appear to be distinct from other factors linked with overall cannabis use.

SUMMARY

CUD development is likely the product of interactions between biological, psychological, social, and environmental factors. However, many more well-planned and developmentally sensitive prospective studies are needed to identify specific and reliable risk factors for CUD development.

Parents, Peers, and Places: Young Urban Adolescents' Microsystems and Substance Use Involvement

Limited research is available that explains complex contextual and interactive effects of microsystems such as family relationships, peer networks, and place-based influences have on urban adolescent substance use. We contend that research into these complex processes is improved by integrating psychological, social, and geographic data to better understand urban adolescent substance use involvement. Accordingly, we tested a longitudinal, 3-way moderation model to determine if the direct effect of teen-parent relationships on substance use involvement is moderated by peer network characteristics, which in turn is moderated by the risk and protective attributes within urban adolescents' activity spaces, among a sample of 248 adolescents. Results revealed that peer networks moderate the effects of relations with parents on substance use involvement for those adolescents with higher levels of risk attributes within their activity space, but not for those who spend time in locations with less risk. Thus, the teen-parent relationship interacts with peer net-work characteristics, for those urban adolescents whose activity space is constituted within high-risk environments. We conclude that peer networks have important interactive effects with family relationships that influence substance use, and that this is particularly salient for young adolescents who are exposed to risky environments. This finding underscores the importance of continued study into the interrelations among microsystems of urban adolescents, and provides further support that substance use is a social practice that is constituted within the unique geography of young adolescents' lives.

Neighborhood environment and marijuana use in urban young adults

Risk factors for marijuana use in older adolescents and young adults have focused primarily on family environment and peer affiliation. A growing body of work has examined the relationship between environmental context and young adult substance use. This study builds on previous research linking neighborhood environment to young adult marijuana use by exploring two distinct features of neighborhoods, namely the physical (e.g., broken windows) and social environment (e.g., adults watching youth). Data were obtained from a longitudinal sample of 398 predominately African American young adults living in an urban environment. The data also included observational measures of physical and social order and disorder collected on the young adult's residential block. Exploratory structural equation modeling (ESEM) was utilized to test hypothesized relationships between these two features of the neighborhood environment and past year young adult marijuana use. A two-factor model of neighborhood environment with good fit indices was selected (CFI = 0.97, RMSEA = 0.037). There was a positive and significant direct effect from neighborhood physical disorder to marijuana use (0.219, p < 0.05) controlling for gender, race, and free and reduced price meal (FARPM) status. The direct effect from neighborhood social environment to marijuana use was not significant. These results converge with previous research linking vacant housing with young adult marijuana use but do not provide empirical support for the neighborhood social environment as a determinant of drug taking. Better explication of the social environment is needed to understand its relationship to drug use.

Early Cannabis Use, Polygenic Risk Score for Schizophrenia and Brain Maturation in Adolescence

IMPORTANCE

Cannabis use during adolescence is known to increase the risk for schizophrenia in men. Sex differences in the dynamics of brain maturation during adolescence may be of particular importance with regard to vulnerability of the male brain to cannabis exposure.

OBJECTIVE

To evaluate whether the association between cannabis use and cortical maturation in adolescents is moderated by a polygenic risk score for schizophrenia.

DESIGN, SETTING, AND PARTICIPANTS

Observation of 3 population-based samples included initial analysis in 1024 adolescents of both sexes from the Canadian Saguenay Youth Study (SYS) and follow-up in 426 adolescents of both sexes from the IMAGEN Study from 8 European cities and 504 male youth from the Avon Longitudinal Study of Parents and Children (ALSPAC) based in England. A total of 1577 participants (aged 12-21 years; 899 [57.0%] male) had (1) information about cannabis use; (2) imaging studies of the brain; and (3) a polygenic risk score for schizophrenia across 108 genetic loci identified by the Psychiatric Genomics Consortium. Data analysis was performed from March 1 through December 31, 2014.

MAIN OUTCOMES AND MEASURES

Cortical thickness derived from T1-weighted magnetic resonance images. Linear regression tests were used to assess the relationships between cannabis use, cortical thickness, and risk score.

RESULTS

Across the 3 samples of 1574 participants, a negative association was observed between cannabis use in early adolescence and cortical thickness in male participants with a high polygenic risk score. This observation was not the case for low-risk male participants or for the low- or high-risk female participants. Thus, in SYS male participants, cannabis use interacted with risk score vis-à-vis cortical thickness (P = .009); higher scores were associated with lower thickness only in males who used cannabis. Similarly, in the IMAGEN male participants, cannabis use interacted with increased risk score vis-à-vis a change in decreasing cortical thickness from 14.5 to 18.5 years of age (t137 = -2.36; P = .02). Finally, in the ALSPAC high-risk group of male participants, those who used cannabis most frequently (≥61 occasions) had lower cortical thickness than those who never used cannabis (difference in cortical thickness, 0.07 [95% CI, 0.01-0.12]; P = .02) and those with light use (<5 occasions) (difference in cortical thickness, 0.11 [95% CI, 0.03-0.18]; P = .004).

CONCLUSIONS AND RELEVANCE

Cannabis use in early adolescence moderates the association between the genetic risk for schizophrenia and cortical maturation among male individuals. This finding implicates processes underlying cortical maturation in mediating the link between cannabis use and liability to schizophrenia.

Testosterone and its effects on human male adolescent mood and behavior: a systematic review

PURPOSE

During human puberty, there is an approximate 30-fold increase in testosterone production in boys. This increase is often linked to changes in mood and behavior in adolescence such as aggression, an increase in risk taking, and depression. The aim of this systematic review was to determine what evidence exists on the effects of endogenous testosterone on behavior and mood in males during adolescence.

METHODS

The following databases were searched: MEDLINE, Pre-MEDLINE, Education Resources Information Centre, PsycINFO, EMBASE, Scopus, and Web of Science. Only human studies were included. The study is community based, and the participants were healthy male adolescents within the age range of 9-18 years. Studies were required to have a validated mood and/or behavior assessment contemporaneous with a timed testosterone measurement.

RESULTS

A total of 27 studies met the inclusion criteria of which only one was a longitudinal study. The remaining 26 studies were cross sectional in their analysis. As a variety of measurement tools were used, no meta-analysis was possible. Most studies focused on aggression. The one longitudinal study looking at testosterone and aggression showed little relationship with concurrent changes in aggression. Most of the cross-sectional studies of adolescent males observed relationships between aggression and testosterone levels. With respect to other behaviors and moods and/or affect, no consistent relationships with testosterone were observed in cross-sectional studies.

CONCLUSIONS

This systematic review concludes that there are insufficient longitudinal data of high methodological quality to currently confirm that changing testosterone levels during puberty are significantly associated with mood and behavior in adolescent males. To discount these findings is to risk apportioning blame inappropriately and missing other important diagnoses in adolescent males.

Neighborhood Social Context and Individual Polycyclic Aromatic Hydrocarbon Exposures Associated with Child Cognitive Test Scores

Childhood cognitive and test-taking abilities have long-term implications for educational achievement and health, and may be influenced by household environmental exposures and neighborhood contexts. This study evaluates whether age 5 scores on the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R, administered in English) are associated with polycyclic aromatic hydrocarbon (PAH) exposure and neighborhood context variables including poverty, low educational attainment, low English language proficiency, and inadequate plumbing. The Columbia Center for Children's Environmental Health enrolled African-American and Dominican-American New York City women during pregnancy, and conducted follow-up for subsequent childhood health outcomes including cognitive test scores. Individual outcomes were linked to data characterizing 1-km network buffers around prenatal addresses, home observations, interviews, and prenatal PAH exposure data from personal air monitors. Prenatal PAH exposure above the median predicted 3.5 point lower total WPPSI-R scores and 3.9 point lower verbal scores; the association was similar in magnitude across models with adjustments for neighborhood characteristics. Neighborhood-level low English proficiency was independently associated with 2.3 point lower mean total WPPSI-R score, 1.2 point lower verbal score, and 2.7 point lower performance score per standard deviation. Low neighborhood-level educational attainment was also associated with 2.0 point lower performance scores. In models examining effect modification, neighborhood associations were similar or diminished among the high PAH exposure group, as compared with the low PAH exposure group. Early life exposure to personal PAH exposure or selected neighborhood-level social contexts may predict lower cognitive test scores. However, these results may reflect limited geographic exposure variation and limited generalizability.

Relation among HPA and HPG neuroendocrine systems, transmissible risk and neighborhood quality on development of substance use disorder: results of a 10-year prospective study

BACKGROUND

Research has shown involvement of hormones of the hypothalamic pituitary adrenal (HPA) axis and hypothalamic pituitary gonadal (HPG) axis in the regulation of behaviors that contribute to SUD risk and its intergenerational transmission. Neighborhood environment has also been shown to relate to hormones of these two neuroendocrine systems and behaviors associated with SUD liability. Accordingly, it was hypothesized that (1) parental SUD severity and neighborhood quality correlate with activity of the HPG axis (testosterone level) and HPA axis (cortisol stability), and (2) transmissible risk during childhood mediates these hormone variables on development of SUD measured in adulthood.

METHODS

Transmissible risk for SUD measured by the transmissible liability index (TLI; Vanyukov et al., 2009) along with saliva cortisol and plasma testosterone were prospectively measured in boys at ages 10-12 and 16. Neighborhood quality was measured using a composite score encompassing indicators of residential instability and economic disadvantage. SUD was assessed at age 22.

RESULTS

Neither hormone variable cross-sectionally correlated with transmissible risk measured at ages 10-12 and 16. However, the TLI at age 10-12 predicted testosterone level and cortisol stability at age 16. Moreover, testosterone level, correlated with cortisol stability at age 16, predicted SUD at age 22.

CONCLUSION

HPA and HPG axes activity do not underlie variation in TLI, however, high transmissible risk in childhood predicts neuroendocrine system activity presaging development of SUD.

A review on the relationship between testosterone and life-course persistent antisocial behavior

Life-course persistent antisocial behavior is 10 to 14 times more prevalent in males and it has been suggested that testosterone levels could account for this gender bias. Preliminary studies with measures of fetal testosterone find inconsistent associations with antisocial behavior, especially studies that use the 2D:4D ratio as a proxy for fetal testosterone. However, circulating testosterone consistently shows positive associations with antisocial behaviors throughout childhood, adolescence, and adulthood, particularly in males. It is suggested that high fetal/circulating testosterone interactively influence the maturation and functionality of mesolimbic dopaminergic circuitry, right orbitofrontal cortex, and cortico-subcortical connectivity, resulting in a strong reward motivation, low social sensitivity, and dampened regulation of strong motivational/emotional processes. The link between these testosterone induced endophenotypes and actual display of antisocial behavior is strongly modulated by different social (e.g., social rejection, low SES) and genetic (e.g., MAOA, 5HTT) risk factors that can disturb socio-, psycho-, and biological development and interact with testosterone in shaping behavior. When these additional risk factors are present, the testosterone induced endophenotypes may increase the risk for a chronic antisocial lifestyle. However, behavioral endophenotypes induced by testosterone can also predispose towards socially adaptive traits such as a strong achievement motivation, leadership, fair bargaining behaviors, and social assertiveness. These adaptive traits are more likely to emerge when the high testosterone individual has positive social experiences that promote prosocial behaviors such as strong and secure attachments with his caregivers, affiliation with prosocial peers, and sufficient socioeconomic resources. A theoretical model is presented, various hypotheses are examined, and future venues for research are discussed.

The dominance behavioral system and psychopathology: evidence from self-report, observational, and biological studies

The dominance behavioral system (DBS) can be conceptualized as a biologically based system that guides dominance motivation, dominant and subordinate behavior, and responsivity to perceptions of power and subordination. A growing body of research suggests that problems with the DBS are evident across a broad range of psychopathologies. We begin by describing psychological, social, and biological correlates of the DBS. Extensive research suggests that externalizing disorders, mania proneness, and narcissistic traits are related to heightened dominance motivation and behaviors. Mania and narcissistic traits also appear related to inflated self-perceptions of power. Anxiety and depression are related to subordination and submissiveness, as well as a desire to avoid subordination. Models of the DBS have received support from research with humans and animals; from self-report, observational, and biological methods; and use of naturalistic and experimental paradigms. Limitations of available research include the relative lack of longitudinal studies using multiple measures of the DBS and the absence of relevant studies using diagnosed samples to study narcissistic personality disorder and bipolar disorder. We provide suggestions for future research on the DBS and psychopathology, including investigations of the potential usefulness of DBS in differentiating specific disorder outcomes, the need for more sophisticated biological research, and the value of longitudinal dynamical research. Implications of using the DBS as a tool in clinical assessment and treatment are discussed.

Application of person-centered medicine in addiction

This article discusses human individuality within a lifespan developmental perspective. The practical application of an individual differences framework for diagnosis, prevention and treatment of addiction is described. A brief overview of the methods conducive to knowledge development within the rubric of person-centered medicine that are available to practitioners working in office and clinic settings concludes the discussion.

Revisiting the concepts of risk and protective factors for understanding the etiology and development of substance use and substance use disorders: implications for prevention

Over the past 20 years we have accumulated a greater knowledge and understanding of the genetic, neurobiological, and behavioral factors that may be associated with young people initiating the use of drugs and other substances and to progressing from use to abuse and dependence. This knowledge suggests that individuals may be "predisposed" to substance use disorders (SUD) and that the actual engagement in these behaviors depends on their environmental experiences from micro to macro levels. This paper summarizes this knowledge base and supports a developmental framework that examines the interaction of posited genetic, psychological, and neurobiological "predispositions" to SUD and those environmental influences that exacerbate this vulnerability.

New variable selection methods for zero-inflated count data with applications to the substance abuse field

Zero-inflated count data are very common in health surveys. This study develops new variable selection methods for the zero-inflated Poisson regression model. Our simulations demonstrate the negative consequences which arise from the ignorance of zero-inflation. Among the competing methods, the one-step SCAD method is recommended because it has the highest specificity, sensitivity, exact fit, and lowest estimation error. The design of the simulations is based on the special features of two large national databases commonly used in the alcoholism and substance abuse field so that our findings can be easily generalized to the real settings. Applications of the methodology are demonstrated by empirical analyses on the data from a well-known alcohol study.

The growth of neighborhood disorder and marijuana use among urban adolescents: a case for policy and environmental interventions

OBJECTIVE

This study examines the growth of neighborhood disorder and subsequent marijuana use among urban adolescents transitioning into young adulthood.

METHOD

Data are derived from a longitudinal sample of 434 predominately African American 12th graders followed-up at 2 years after high school. The data are rich in repeated measures documenting substance use and misuse and neighborhood characteristics. Growth mixture modeling was used to examine how neighborhood disorder trajectories, measured through the presence of abandoned buildings on the blocks where participants reside, influence subsequent drug use beginning in late adolescence and into young adulthood.

RESULTS

A four-class solution characterizing neighborhood growth was selected as the final model and included rapidly improving, slightly improving, always-good, and deteriorating neighborhoods. Young adults living in neighborhoods that had been deteriorating over time were 30% more likely to use marijuana 2 years after high school than adolescents living in always-good neighborhoods (odds ratio = 1.30, p = .034). There was no relationship between living in a neighborhood that was improving and marijuana use.

CONCLUSIONS

This study identified a salient and malleable neighborhood characteristic, abandoned housing, which predicted elevated risk for young-adult marijuana use. This research supports environmental strategies that target abandoned buildings as a means to improve health and health behaviors for community residents, particularly young-adult substance use.