Shaquanna Brown

The NKI-Rockland Sample: A Model for Accelerating the Pace of Discovery Science in Psychiatry

The National Institute of Mental Health strategic plan for advancing psychiatric neuroscience calls for an acceleration of discovery and the delineation of developmental trajectories for risk and resilience across the lifespan. To attain these objectives, sufficiently powered datasets with broad and deep phenotypic characterization, state-of-the-art neuroimaging, and genetic samples must be generated and made openly available to the scientific community. The enhanced Nathan Kline Institute-Rockland Sample (NKI-RS) is a response to this need. NKI-RS is an ongoing, institutionally centered endeavor aimed at creating a large-scale (N > 1000), deeply phenotyped, community-ascertained, lifespan sample (ages 6–85 years old) with advanced neuroimaging and genetics. These data will be publically shared, openly, and prospectively (i.e., on a weekly basis). Herein, we describe the conceptual basis of the NKI-RS, including study design, sampling considerations, and steps to synchronize phenotypic and neuroimaging assessment. Additionally, we describe our process for sharing the data with the scientific community while protecting participant confidentiality, maintaining an adequate database, and certifying data integrity. The pilot phase of the NKI-RS, including challenges in recruiting, characterizing, imaging, and sharing data, is discussed while also explaining how this experience informed the final design of the enhanced NKI-RS. It is our hope that familiarity with the conceptual underpinnings of the enhanced NKI-RS will facilitate harmonization with future data collection efforts aimed at advancing psychiatric neuroscience and nosology.

Relationship of Trauma Symptoms to Amygdala-Based Functional Brain Changes in Adolescents

In this pilot study, amygdala connectivity related to trauma symptoms was explored using resting-state functional magnetic resonance imaging (R-fMRI) in 23 healthy adolescents ages 13-17 years with no psychiatric diagnoses. Adolescents completed a self-report trauma symptom checklist and a R-fMRI scan. We examined the relationship of trauma symptoms to resting-state functional connectivity of the amygdala. Increasing self-report of trauma symptoms by adolescents was associated with increasing functional connectivity with the right amygdala and a local limbic cluster and decreasing functional connectivity with the amygdala and a long-range frontoparietal cluster to the left amygdala, which can be a hallmark of immaturity. These pilot findings in adolescents provide preliminary evidence that even mild trauma symptoms can be linked to the configuration of brain networks associated with the amygdala.

Associations Between Maltreatment History and Severity of Substance Use Behavior in Youth in Foster Care

Substance use (SU) in youth remains a significant public health concern and a risk factor for morbidity and mortality in adolescents. The present study offers examination of the association between severity and chronicity of maltreatment history and SU in youth in foster care. Two hundred and ten (48% female) foster youth with a mean age of 12.71 years (SD = 2.95 years) completed surveys using an audio-computer-assisted self-interview program. Results revealed 31% of participants reported past-year SU, and substance users had a mean CRAFFT score of 3.43 (SD = 1.90). Reported age of SU onset was 11.08 years (SD = 2.21 years). The SU measurement model demonstrated excellent fit in this sample. Accounting for both youth age and youth placement type, the structural model with maltreatment predicting SU severity demonstrated strong model fit with a significant path between maltreatment and SU. Youth in residential facilities and older youth had higher rates of use than those residing in traditional foster home environments and younger youth. Findings provide additional support for the link between maltreatment experiences and SU severity in foster youth and suggest the need for screening and intervention services appropriate for this high-risk population.

Accounting for the associations between child maltreatment and internalizing problems: the role of alexithymia

Internalizing difficulties are one of the most widely documented consequences of child maltreatment. However, there is a need for studies delineating the factors that account for this association. Despite research showing that alexithymia is associated with both child maltreatment and internalizing problems, the role of alexithymia in the link between child maltreatment and internalizing problems has not received much attention in the literature. The current study evaluated whether a history of child maltreatment was associated with symptoms of depression, anxiety, and loneliness in emerging adulthood, and whether alexithymia partially accounted for these associations. Participants included 339 emerging adults ranging between 18 and 25 years of age (M=19.00, SD=1.26, 51.3% male). Exposure to child maltreatment (i.e., physical abuse, physical neglect, sexual abuse, emotional abuse, and emotional neglect) was positively associated with depression, anxiety, and loneliness symptoms. Tests of indirect effects suggested that associations between emotional neglect and symptoms of depression, anxiety, and loneliness were partially explained by alexithymia. However, alexithymia did not account for any other associations between the remaining four maltreatment types and internalizing problems. Findings highlight the need for further evaluation of the factors that might account for associations between child maltreatment and internalizing difficulties. Future directions and implications for interventions are reviewed.

Impulsivity as a moderator of the associations between child maltreatment types and body mass index

Child maltreatment has emerged as an important risk factor for adult obesity (Danese & Tan, 2014; Hemmingsson et al., 2014). However, there is a need for research delineating the factors that play a role in this association. Impulsivity has been shown to be associated with both child maltreatment (Brodsky et al., 2001) and body mass index (BMI; Cortese et al., 2008; Thamotharan et al., 2013). Further, given previous research showing that adverse events interact with impulsivity to predict hazardous drinking behaviors (Fox et al., 2010), there is reason to hypothesize that child maltreatment might interact with impulsivity to predict other adverse health outcomes, such as elevated BMI. Accordingly, the current study examined whether impulsivity moderated the association between child maltreatment types (i.e., physical abuse, physical neglect, sexual abuse, emotional abuse, and emotional neglect) and BMI. The sample was comprised of 500 undergraduate students (49.6% male) between the ages of 18 and 25 years. Regression analyses suggested that maltreatment types and impulsivity were not uniquely associated with BMI. However, impulsivity moderated the association between childhood sexual abuse and adult BMI, such that BMI was highest at high levels of both sexual abuse and impulsivity. Impulsivity did not moderate the associations between the other child maltreatment types and BMI. Limitations, future directions, and clinical implications of this research are discussed.

The Role of Negative Life Events in Comorbid Reactive Aggression and Marijuana Use Initiation among Latino Adolescents

Compelling epidemiological evidence shows that marijuana use is highly comorbid with aggressive behavior, particularly among adolescents and young adults; yet the causal nexus between these 2 phenomena remains elusive. To better understand the comorbidity of specific subtypes of aggression and marijuana use, this study evaluated associations between proactive and reactive aggression and marijuana use initiation and examined whether negative life events (NLEs) partially accounted for the link between reactive aggression and marijuana use initiation in a sample of Latino adolescents (N = 144, 54% male, mean age = 16.25 years). Results indicated that approximately 43% of participants had tried marijuana. NLEs were associated with both marijuana use initiation and reactive aggression, but were unrelated to proactive aggression, thereby providing support for similar environmental correlates for reactive aggression and marijuana use. Further, a test of indirect effects suggested that NLEs partially accounted for the link between reactive aggression and marijuana use initiation, with NLEs accounting for 14% of the variance in this association. Implications for intervention and future directions for research are discussed.

Associations between emotional abuse and neglect and dimensions of alexithymia: The moderating role of sex.

Objective: Child maltreatment, specifically emotional maltreatment (i.e., an act, such as belittling, blaming, or rejection, that is potentially harmful to a child’s emotional development), has emerged as an important correlate of alexithymia. However, the evidence is mixed with regard to how emotional abuse and neglect might relate to dimensions of alexithymia (i.e., externally oriented thinking, difficulty describing feelings, and difficulty identifying feelings). Furthermore, research is needed to identify individual factors that might influence these associations. The current study examined the links between emotional abuse and neglect and externally oriented thinking, difficulty describing feelings, and difficulty identifying feelings and evaluated whether sex moderated these associations. Method: Participants included 500 emerging adults (49.6% male) who completed an online battery of questionnaires assessing history of child maltreatment and dimensions of alexithymia. Results: Regression analyses revealed that emotional abuse was associated with difficulty describing feelings and externally oriented thinking, but not difficulty identifying feelings. Emotional neglect was associated with difficulty identifying feelings, but not difficulty describing feelings or externally oriented thinking. There were no sex differences associated with difficulty describing feelings or externally oriented thinking. However, sex moderated the associations between emotional abuse and neglect and difficulty identifying feelings such that emotional abuse and neglect were both more strongly associated with difficulty identifying feelings for females. Conclusion: These results suggest that, in the aftermath of emotional maltreatment, sex may play an important role in the development of difficulty identifying feelings.

The Role of Hostile Attributions in the Associations Between Child Maltreatment and Reactive and Proactive Aggression

ABSTRACT This study examined the relations between child maltreatment and reactive and proactive functions of aggression, and whether hostile attribution biases partially accounted for these associations in a sample of 339 college students (M age = 19, 51% male). Child maltreatment was associated with reactive, but not proactive, aggression, and instrumental hostile attribution biases accounted for this association. Relational hostile attributions were correlated with both reactive and proactive aggression, but did not play a role in the link between child maltreatment and reactive aggression.

Anxiety symptoms as a moderator of the reciprocal links between forms of aggression and peer victimization in middle childhood

The current short-term longitudinal study evaluated whether anxiety symptoms moderated the bidirectional associations between forms (i.e., physical and relational) of aggression and peer victimization over a 1-year period during middle childhood. Participants were 228 predominantly Caucasian children (50.4% boys; M = 8.32 years, SD = .95 years) in the second through fourth grades and their homeroom teachers. Children completed a self-report measure of anxiety symptoms at Time 1. Peer victimization was assessed using self-reports at Time 1 and approximately 1 year later (Time 2), and teachers provided ratings of childrens aggressive behavior at both time points. A series of cross-lagged path analysis models indicated that high (+1 SD) initial levels of anxiety symptoms exacerbated the prospective link from Time 1 relational aggression to Time 2 peer victimization; conversely, when initial levels of anxiety symptoms were low (-1 SD), relational aggression predicted lower levels of subsequent peer victimization. Time 1 peer victimization was also found to predict lower levels of Time 2 physical aggression when initial levels of anxiety symptoms were low, and Time 1 anxiety symptoms were uniquely related to higher levels of relational aggression over a 1-year period. Regions of significance were calculated to further decompose significant interactions, which did not differ according to gender. Study findings are discussed within a social information processing theoretical framework, and directions for future research and implications for practice are reviewed. Specifically, co-occurring anxiety symptoms may need to be addressed in interventions for both aggression and peer victimization during middle childhood.

A descriptive study on selected growth parameters and growth hormone receptor gene in healthy young adults from the American Midwest

CONTEXT The first study of growth hormone receptor (GHR) genotypes in healthy young adults in the United States attending a Midwestern university and impact on selected growth parameters. OBJECTIVE To describe the frequency of GHR genotypes in a sample of healthy young adults from the United States attending a university in the Midwest and analyze the relationship between GHR genotypes and selected growth parameters. DESIGN Saliva was collected from 459 healthy young adults (237 females, 222 males; age range = 18-25 y) and DNA isolated for genotyping of GHR alleles (fl/fl, fl/d3, or d3/d3). Selected growth parameters were collected and GHR genotype data examined for previously reported associations (e.g., height, weight or bone mass density) or novel findings (e.g., % body water and index finger length). RESULTS We found 219 participants (48%) homozygous for fl/fl, 203 (44%), heterozygous fl/d3 and 37 (8%) homozygous d3/d3. The distribution of GHR genotypes in our participants was consistent with previous reports of non-US populations. Several anthropometric measures differed by sex. The distribution of GHR genotypes did not significantly differ by sex, weight, or other anthropometric measures. However, the fl/d3 genotype was more common among African-Americans. CONCLUSIONS Our study of growth and anthropometric parameters in relationship to GHR genotypes found no association with height, weight, right index finger length, BMI, bone mass density, % body fat or % body water in healthy young adults. We did identify sex differences with increased body fat, decreased bone density, body water and index finger length in females.