News and Commentary Archive

Explore recent scientific discoveries and news as well as CLBB events, commentary, and press.

Mission

The speed of technology in neuroscience as it impacts ethical and just decisions in the legal system needs to be understood by lawyers, judges, public policy makers, and the general public. The Massachusetts General Hospital Center for Law, Brain, and Behavior is an academic and professional resource for the education, research, and understanding of neuroscience and the law. Read more

Genome-Wide Association Studies of Posttraumatic Stress Disorder in 2 Cohorts of US Army Soldiers

By Murray B. Stein, Chia-Yen Chen, Robert J. Ursano, Tianxi Cai, Joel Gelernter, Steven G. Heeringa, Sonia Jain, Kevin P. Jensen, Adam X. Maihofer, Colter Mitchell, Caroline M. Nievergelt, Matthew K. Nock, Benjamin M. Neale, Renato Polimanti, Stephan Ripke, Xiaoying Sun, Michael L. Thomas, Qian Wang, Erin B. Ware, Susan Borja, Ronald C. Kessler, and Jordan W. Smoller | JAMA Psychiatry | May 11, 2016

Abstract:

Importance —  Posttraumatic stress disorder (PTSD) is a prevalent, serious public health concern, particularly in the military. The identification of genetic risk factors for PTSD may provide important insights into the biological foundation of vulnerability and comorbidity.

Objective —  To discover genetic loci associated with the lifetime risk for PTSD in 2 cohorts from the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS).

Design, Setting, and Participants —  Two coordinated genome-wide association studies of mental health in the US military contributed participants. The New Soldier Study (NSS) included 3167 unique patients with PTSD and 4607 trauma-exposed control individuals; the Pre/Post Deployment Study (PPDS) included 947 unique patients with PTSD and 4969 trauma-exposed controls. The NSS data were collected from February 1, 2011, to November 30, 2012; the PDDS data, from January 9 to April 30, 2012. The primary analysis compared lifetime DSM-IV PTSD cases with trauma-exposed controls without lifetime PTSD. Data were analyzed from March 18 to December 27, 2015.

Main Outcomes and Measures —  Association analyses for PTSD used logistic regression models within each of 3 ancestral groups (European, African, and Latino American) by study, followed by meta-analysis. Heritability and genetic correlation and pleiotropy with other psychiatric and immune-related disorders were estimated.

Results —  The NSS population was 80.7% male (6277 of 7774 participants; mean [SD] age, 20.9 [3.3] years); the PPDS population, 94.4% male (5583 of 5916 participants; mean [SD] age, 26.5 [6.0] years). A genome-wide significant locus was found in ANKRD55 on chromosome 5 (rs159572; odds ratio [OR], 1.62; 95% CI, 1.37-1.92; P = 2.34 × 10−8) and persisted after adjustment for cumulative trauma exposure (adjusted OR, 1.64; 95% CI, 1.39-1.95; P = 1.18 × 10−8) in the African American samples from the NSS. A genome-wide significant locus was also found in or near ZNF626 on chromosome 19 (rs11085374; OR, 0.77; 95% CI, 0.70-0.85; P = 4.59 × 10−8) in the European American samples from the NSS. Similar results were not found for either single-nucleotide polymorphism in the corresponding ancestry group from the PPDS sample, in other ancestral groups, or in transancestral meta-analyses. Single-nucleotide polymorphism–based heritability was nonsignificant, and no significant genetic correlations were observed between PTSD and 6 mental disorders or 9 immune-related disorders. Significant evidence of pleiotropy was observed between PTSD and rheumatoid arthritis and, to a lesser extent, psoriasis.

Conclusions and Relevance —  In the largest genome-wide association study of PTSD to date, involving a US military sample, limited evidence of association for specific loci was found. Further efforts are needed to replicate the genome-wide significant association with ANKRD55—associated in prior research with several autoimmune and inflammatory disorders—and to clarify the nature of the genetic overlap observed between PTSD and rheumatoid arthritis and psoriasis.

Read the full article here.

Gating Deficit Heritability and Correlation With Increased Clinical Severity in Schizophrenia Patients With Positive Family History

By Tiffany A. Greenwood, Gregory A. Light, Neal R. Swerdlow, Monica E. Calkins, Michael F. Green, Raquel E. Gur, Ruben C. Gur, Laura C. Lazzeroni, Keith H. Nuechterlein, Ann Olincy, Allen D. Radant, Larry J. Seidman, Larry J. Siever, Jeremy M. Silverman, William S. Stone, Catherine A. Sugar, Debby W. Tsuang, Ming T. Tsuang, Bruce I. Turetsky, Robert Freedman, and David L. Braff | The American Journal of Psychiatry | August 10, 2015

Abstract:

Method:

A total of 296 nuclear families consisting of a schizophrenia proband, at least one unaffected sibling, and both parents underwent a comprehensive endophenotype and clinical characterization. The Family Interview for Genetic Studies was administered to all participants and used to obtain convergent psychiatric symptom information for additional first-degree relatives. Among the families, 97 were multiply affected, and 96 were singletons.

Results:

Both PPI and P50 gating displayed substantially increased heritability in the 97 multiply affected families (47% and 36%, respectively) compared with estimates derived from the entire sample of 296 families (29% and 20%, respectively). However, no evidence for heritability was observed for either measure in the 96 singleton families. Schizophrenia probands derived from the multiply affected families also displayed a significantly increased severity of clinical symptoms compared with those from singleton families.

Conclusions:

Extending the ‘Cross-Disorder’ Relevance of Executive Functions to Dimensional Neuropsychiatric Traits in Youth

By Lauren M. McGrath, Ellen B. Braaten, Nathan D. Doty, Brian L. Willoughby, H. Kent Wilson, Ellen H. O’Donnell, Mary K. Colvin, Hillary L. Ditmars, Jessica E. Blais, Erin N. Hill, Aaron Metzger, Roy H. Perlis, Erik G. Willcutt, Jordan W. Smoller, Irwin D. Waldman, Stephen V. Faraone, Larry J. Seidman, and Alysa E. Doyle | The Journal of Child Psychology and Psychiatry | September 28, 2015

Abstract:

Background

Evidence that different neuropsychiatric conditions share genetic liability has increased interest in phenotypes with ‘cross-disorder’ relevance, as they may contribute to revised models of psychopathology. Cognition is a promising construct for study; yet, evidence that the same cognitive functions are impaired across different forms of psychopathology comes primarily from separate studies of individual categorical diagnoses versus controls. Given growing support for dimensional models that cut across traditional diagnostic boundaries, we aimed to determine, within a single cohort, whether performance on measures of executive functions (EFs) predicted dimensions of different psychopathological conditions known to share genetic liability.

Methods

Data are from 393 participants, ages 8–17, consecutively enrolled in the Longitudinal Study of Genetic Influences on Cognition (LOGIC). This project is conducting deep phenotyping and genomic analyses in youth referred for neuropsychiatric evaluation. Using structural equation modeling, we examined whether EFs predicted variation in core dimensions of the autism spectrum disorder, bipolar illness, and schizophrenia (including social responsiveness, mania/emotion regulation, and positive symptoms of psychosis, respectively).

Results

We modeled three cognitive factors (working memory, shifting, and executive processing speed) that loaded on a second-order EF factor. The EF factor predicted variation in our three target traits, but not in a negative control (somatization). Moreover, this EF factor was primarily associated with the overlapping (rather than unique) variance across the three outcome measures, suggesting that it related to a general increase in psychopathology symptoms across those dimensions.

Conclusions

Findings extend support for the relevance of cognition to neuropsychiatric conditions that share underlying genetic risk. They suggest that higher-order cognition, including EFs, relates to the dimensional spectrum of each of these disorders and not just the clinical diagnoses. Moreover, results have implications for bottom-up models linking genes, cognition, and a general psychopathology liability.

Read the full article here.

Variation in CACNA1C is Associated with Amygdala Structure and Function in Adolescents

By Jennifer A. Sumner, Margaret A. Sheridan, Stacy S. Drury, Kyle C. Esteves, Kate Walsh, Karestan C. Koenen, and Katie A. McLaughlin | Journal of Child and Adolescent Psychopharmacology | September 24, 2015

Abstract:

Objective: Genome-wide association studies have identified allelic variation in CACNA1C as a risk factor for multiple psychiatric disorders associated with limbic system dysfunction, including bipolar disorder, schizophrenia, and depression. The CACNA1C gene codes for a subunit of L-type voltage-gated calcium channels, which modulate amygdala function. Although CACNA1C genotype appears to be associated with amygdala morphology and function in adults with and without psychopathology, whether genetic variation influences amygdala structure and function earlier in development has not been examined.

Methods: In this first investigation of the neural correlates of CACNA1C in young individuals, we examined associations between two single nucleotide polymorphisms in CACNA1C (rs1006737 and rs4765914) with amygdala volume and activation during an emotional processing task in 58 adolescents and young adults 13–20 years of age.

Results: Minor (T) allele carriers of rs4765914 exhibited smaller amygdala volume than major (C) allele homozygotes (β=−0.33, p=0.006). Furthermore, minor (A) allele homozygotes of rs1006737 exhibited increased blood–oxygen-level-dependent (BOLD) signal in the amygdala when viewing negative (vs. neutral) stimuli (β=0.29, p=0.040) and decreased BOLD signal in the amygdala when instructed to downregulate their emotional response to negative stimuli (β=−0.38, p=0.009). Follow-up analyses indicated that childhood trauma did not moderate the associations of CACNA1C variation with amygdala structure and function (ps>0.170).

Conclusions: Findings indicate that CACNA1C-related differences in amygdala structure and function are present by adolescence. However, population stratification is a concern, given the racial/ethnic heterogeneity of our sample, and our findings do not have direct clinical implications currently. Nevertheless, these results suggest that developmentally informed research can begin to shed light on the time course by which genetic liability may translate into neural differences associated with vulnerability to psychopathology.

Read the full article here.

Spark for a Stagnant Search

The New York Times | Carl Zimmer and Benedict Carey | July 21, 2014

One day in 1988, a college dropout named Jonathan Stanley was visiting New York City when he became convinced that government agents were closing in on him.

He bolted, and for three days and nights raced through the city streets and subway tunnels. His flight ended in a deli, where he climbed a plastic crate and stripped off his clothes. The police took him to a hospital, and he finally received effective treatment two years after getting a diagnosis of bipolar disorder.

“My son’s life was saved,” his father, Ted Stanley, said recently. When he himself was in college, he added, “those drugs didn’t exist; I would have had a nonfunctioning brain all the rest of my life.”

The older Mr. Stanley, 84, who earned a fortune selling collectibles, created a foundation to support psychiatric research. “I would like to purchase that happy ending for other people,” he said.

Late on Monday, the Broad Institute, a biomedical research center, announced a $650 million donation for psychiatric research from the Stanley Family Foundation — one of the largest private gifts ever for scientific research. Continue reading »