Browsing by Author "Koller, Daniel L."
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Item Assessment of First and Second Degree Relatives of Individuals With Bipolar Disorder Shows Increased Genetic Risk Scores in Both Affected Relatives and Young At-Risk Individuals(Wiley, 2015-10) Fullerton, Janice M.; Koller, Daniel L.; Edenberg, Howard J.; Foroud, Tatiana; Liu, Hai; Glowinski, Anne L.; McInnis, Melvin G.; Wilcox, Holly C.; Frankland, Andrew; Roberts, Gloria; Schofield, Peter R.; Mitchell, Philip B.; Nurnberger, John I.; Department of Biochemistry and Molecular Biology, IU School of MedicineRecent studies have revealed the polygenic nature of bipolar disorder (BP), and identified common risk variants associated with illness. However, the role of common polygenic risk in multiplex families has not previously been examined. The present study examined 249 European-ancestry families from the NIMH Genetics Initiative sample, comparing subjects with narrowly defined BP (excluding bipolar II and recurrent unipolar depression; n = 601) and their adult relatives without BP (n = 695). Unrelated adult controls (n = 266) were from the NIMH TGEN control dataset. We also examined a prospective cohort of young (12–30 years) offspring and siblings of individuals with BPI and BPII disorder (at risk; n = 367) and psychiatrically screened controls (n = 229), ascertained from five sites in the US and Australia and assessed with standardized clinical protocols. Thirty-two disease-associated SNPs from the PGC-BP Working Group report (2011) were genotyped and additive polygenic risk scores (PRS) derived. We show increased PRS in adult cases compared to unrelated controls (P = 3.4 × 10−5, AUC = 0.60). In families with a high-polygenic load (PRS score ≥32 in two or more subjects), PRS distinguished cases with BPI/SAB from other relatives (P = 0.014, RR = 1.32). Secondly, a higher PRS was observed in at-risk youth, regardless of affected status, compared to unrelated controls (GEE-χ2 = 5.15, P = 0.012). This report is the first to explore common polygenic risk in multiplex families, albeit using only a small number of robustly associated risk variants. We show that individuals with BP have a higher load of common disease-associated variants than unrelated controls and first-degree relatives, and illustrate the potential utility of PRS assessment in a family context.Item Association of substance dependence phenotypes in the COGA sample(Wiley, 2015-05) Wetherill, Leah; Agrawal, Arpana; Kapoor, Manav; Bertelsen, Sarah; Bierut, Laura J.; Brooks, Andrew; Dick, Danielle; Hesselbrock, Michie; Hesselbrock, Victor; Koller, Daniel L.; Le, Nhung; Nurnberger Jr., John I.; Salvatore, Jessica E.; Schuckit, Marc; Tischfield, Jay A.; Wang, Jen-Chyong; Xuei, Xiaoling; Edenberg, Howard J.; Porjesz, Bernice; Bucholz, Kathleen; Goate, Alison M.; Foroud, Tatiana; Department of Medical & Molecular Genetics, IU School of MedicineAlcohol and drug use disorders are individually heritable (50%). Twin studies indicate that alcohol and substance use disorders share common genetic influences, and therefore may represent a more heritable form of addiction and thus be more powerful for genetic studies. This study utilized data from 2322 subjects from 118 European-American families in the Collaborative Study on the Genetics of Alcoholism sample to conduct genome-wide association analysis of a binary and a continuous index of general substance dependence liability. The binary phenotype (ANYDEP) was based on meeting lifetime criteria for any DSM-IV dependence on alcohol, cannabis, cocaine or opioids. The quantitative trait (QUANTDEP) was constructed from factor analysis based on endorsement across the seven DSM-IV criteria for each of the four substances. Heritability was estimated to be 54% for ANYDEP and 86% for QUANTDEP. One single-nucleotide polymorphism (SNP), rs2952621 in the uncharacterized gene LOC151121 on chromosome 2, was associated with ANYDEP (P = 1.8 × 10(-8) ), with support from surrounding imputed SNPs and replication in an independent sample [Study of Addiction: Genetics and Environment (SAGE); P = 0.02]. One SNP, rs2567261 in ARHGAP28 (Rho GTPase-activating protein 28), was associated with QUANTDEP (P = 3.8 × 10(-8) ), and supported by imputed SNPs in the region, but did not replicate in an independent sample (SAGE; P = 0.29). The results of this study provide evidence that there are common variants that contribute to the risk for a general liability to substance dependence.Item Characteristics of Bipolar I patients grouped by externalizing disorders(Elsevier, 2015-06-01) Swaminathan, Shanker; Koller, Daniel L.; Foroud, Tatiana; Edenberg, Howard J.; Xuei, Xiaoling; Niculescu, Alexander B.; Bipolar Genome Study (BiGS) Consortium; Nurnberger, John I.; Department of Psychiatry, IU School of MedicineBACKGROUND: Bipolar disorder co-occurs with a number of disorders with externalizing features. The aim of this study is to determine whether Bipolar I (BPI) subjects with comorbid externalizing disorders and a subgroup with externalizing symptoms prior to age 15 have different clinical features than those without externalizing disorders and whether these could be attributed to specific genetic variations. METHODS: A large cohort (N=2505) of Bipolar I subjects was analyzed. Course of illness parameters were compared between an Externalizing Group, an Early-Onset Subgroup and a Non-Externalizing Group in the Discovery sample (N=1268). Findings were validated using an independent set of 1237 BPI subjects (Validation sample). Genetic analyses were carried out. RESULTS: Subjects in the Externalizing Group (and Early-Onset Subgroup) tended to have a more severe clinical course, even in areas specifically related to mood disorder such as cycling frequency and rapid mood switching. Regression analysis showed that the differences are not completely explainable by substance use. Genetic analyses identified nominally associated SNPs; calcium channel genes were not enriched in the gene variants identified. LIMITATIONS: Validation in independent samples is needed to confirm the genetic findings in the present study. CONCLUSIONS: Our findings support the presence of an externalizing disorder subphenotype within BPI with greater severity of mood disorder and possible specific genetic features.Item Disentangling the genetics of lean mass(Oxford University Press, 2019-02-01) Karasik, David; Zillikens, M. Carola; Hsu, Yi-Hsiang; Aghdassi, Ali; Akesson, Kristina; Amin, Najaf; Barroso, Inês; Bennett, David A.; Bertram, Lars; Bochud, Murielle; Borecki, Ingrid B.; Broer, Linda; Buchman, Aron S.; Byberg, Liisa; Campbell, Harry; Campos-Obando, Natalia; Cauley, Jane A.; Cawthon, Peggy M.; Chambers, John C.; Chen, Zhao; Cho, Nam H.; Choi, Hyung Jin; Chou, Wen-Chi; Cummings, Steven R.; De Groot, Lisette C. P. G. M.; De Jager, Phillip L.; Demuth, Ilja; Diatchenko, Luda; Econs, Michael J.; Eiriksdottir, Gudny; Enneman, Anke W.; Eriksson, Joel; Eriksson, Johan G.; Estrada, Karol; Evans, Daniel S.; Feitosa, Mary F.; Fu, Mao; Gieger, Christian; Grallert, Harald; Gudnason, Vilmundur; Lenore, Launer J.; Hayward, Caroline; Hofman, Albert; Homuth, Georg; Huffman, Kim M.; Husted, Lise B.; Illig, Thomas; Ingelsson, Erik; Ittermann, Till; Jansson, John-Olov; Johnson, Toby; Biffar, Reiner; Jordan, Joanne M.; Jula, Antti; Karlsson, Magnus; Khaw, Kay-Tee; Kilpeläinen, Tuomas O.; Klopp, Norman; Kloth, Jacqueline S. L.; Koller, Daniel L.; Kooner, Jaspal S.; Kraus, William E.; Kritchevsky, Stephen; Kutalik, Zoltán; Kuulasmaa, Teemu; Kuusisto, Johanna; Laakso, Markku; Lahti, Jari; Lang, Thomas; Langdahl, Bente L.; Lerch, Markus M.; Lewis, Joshua R.; Lill, Christina; Lind, Lars; Lindgren, Cecilia; Liu, Yongmei; Livshits, Gregory; Ljunggren, Östen; Loos, Ruth J. F.; Lorentzon, Mattias; Luan, Jian'an; Luben, Robert N.; Malkin, Ida; McGuigan, Fiona E.; Medina-Gomez, Carolina; Meitinger, Thomas; Melhus, Håkan; Mellström, Dan; Michaëlsson, Karl; Mitchell, Braxton D.; Morris, Andrew P.; Mosekilde, Leif; Nethander, Maria; Newman, Anne B.; O'Connell, Jeffery R.; Oostra, Ben A.; Orwoll, Eric S.; Palotie, Aarno; Peacock, Munro; Perola, Markus; Peters, Annette; Prince, Richard L.; Psaty, Bruce M.; Räikkönen, Katri; Ralston, Stuart H.; Ripatti, Samuli; Rivadeneira, Fernando; Robbins, John A.; Rotter, Jerome I.; Rudan, Igor; Salomaa, Veikko; Satterfield, Suzanne; Schipf, Sabine; Shin, Chan Soo; Smith, Albert V.; Smith, Shad B.; Soranzo, Nicole; Spector, Timothy D.; Stančáková, Alena; Stefansson, Kari; Steinhagen-Thiessen, Elisabeth; Stolk, Lisette; Streeten, Elizabeth A.; Styrkarsdottir, Unnur; Swart, Karin M. A.; Thompson, Patricia; Thomson, Cynthia A.; Thorleifsson, Gudmar; Thorsteinsdottir, Unnur; Tikkanen, Emmi; Tranah, Gregory J.; Uitterlinden, André G.; Van Duijn, Cornelia M.; Van Schoor, Natasja M.; Vandenput, Liesbeth; Vollenweider, Peter; Völzke, Henry; Wactawski-Wende, Jean; Walker, Mark; Wareham, Nicholas J.; Waterworth, Dawn; Weedon, Michael N.; Wichmann, H-Erich.; Widen, Elisabeth; Williams, Frances M. K.; Wilson, James F.; Wright, Nicole C.; Yerges-Armstrong, Laura M.; Yu, Lei; Zhang, Weihua; Zhao, Jing Hua; Zhou, Yanhua; Nielson, Carrie M.; Harris, Tamara B.; Demissie, Serkalem; Kiel, Douglas P.; Ohlsson, Claes; Medicine, School of MedicineBackground: Lean body mass (LM) plays an important role in mobility and metabolic function. We previously identified five loci associated with LM adjusted for fat mass in kilograms. Such an adjustment may reduce the power to identify genetic signals having an association with both lean mass and fat mass. Objectives: To determine the impact of different fat mass adjustments on genetic architecture of LM and identify additional LM loci. Methods: We performed genome-wide association analyses for whole-body LM (20 cohorts of European ancestry with n = 38,292) measured using dual-energy X-ray absorptiometry) or bioelectrical impedance analysis, adjusted for sex, age, age2, and height with or without fat mass adjustments (Model 1 no fat adjustment; Model 2 adjustment for fat mass as a percentage of body mass; Model 3 adjustment for fat mass in kilograms). Results: Seven single-nucleotide polymorphisms (SNPs) in separate loci, including one novel LM locus (TNRC6B), were successfully replicated in an additional 47,227 individuals from 29 cohorts. Based on the strengths of the associations in Model 1 vs Model 3, we divided the LM loci into those with an effect on both lean mass and fat mass in the same direction and refer to those as "sumo wrestler" loci (FTO and MC4R). In contrast, loci with an impact specifically on LM were termed "body builder" loci (VCAN and ADAMTSL3). Using existing available genome-wide association study databases, LM increasing alleles of SNPs in sumo wrestler loci were associated with an adverse metabolic profile, whereas LM increasing alleles of SNPs in "body builder" loci were associated with metabolic protection. Conclusions: In conclusion, we identified one novel LM locus (TNRC6B). Our results suggest that a genetically determined increase in lean mass might exert either harmful or protective effects on metabolic traits, depending on its relation to fat mass.Item Efficient region-based test strategy uncovers genetic risk factors for functional outcome in bipolar disorder(Elsevier, 2019-01-01) Budde, Monika; Friedrichs, Stefanie; Alliey-Rodriguez, Ney; Ament, Seth; Badner, Judith A.; Berrettini, Wade H.; Bloss, Cinnamon S.; Byerley, William; Cichon, Sven; Comes, Ashley L.; Coryell, William; Craig, David W.; Degenhardt, Franziska; Edenberg, Howard J.; Foroud, Tatiana; Forstner, Andreas J.; Frank, Josef; Gershon, Elliot S.; Goes, Fernando S.; Greenwood, Tiffany A.; Guo, Yiran; Hipolito, Maria; Hood, Leroy; Keating, Brendan J.; Koller, Daniel L.; Lawson, William B.; Liu, Chunyu; Mahon, Pamela B.; McInnis, Melvin G.; McMahon, Francis J.; Meier, Sandra M.; Mühleisen, Thomas W.; Murray, Sarah S.; Nievergelt, Caroline M.; Nurnberger, John I.; Nwulia, Evaristus A.; Potash, James B.; Quarless, Danjuma; Rice, John; Roach, Jared C.; Scheftner, William A.; Schork, Nicholas J.; Shekhtman, Tatyana; Shilling, Paul D.; Smith, Erin N.; Streit, Fabian; Strohmaier, Jana; Szelinger, Szabolcs; Treutlein, Jens; Witt, Stephanie H.; Zandi, Peter P.; Zhang, Peng; Zöllner, Sebastian; Bickeböller, Heike; Falkai, Peter G.; Kelsoe, John R.; Nöthen, Markus M.; Rietschel, Marcella; Schulze, Thomas G.; Malzahn, Dörthe; Biochemistry and Molecular Biology, School of MedicineGenome-wide association studies of case-control status have advanced the understanding of the genetic basis of psychiatric disorders. Further progress may be gained by increasing sample size but also by new analysis strategies that advance the exploitation of existing data, especially for clinically important quantitative phenotypes. The functionally-informed efficient region-based test strategy (FIERS) introduced herein uses prior knowledge on biological function and dependence of genotypes within a powerful statistical framework with improved sensitivity and specificity for detecting consistent genetic effects across studies. As proof of concept, FIERS was used for the first genome-wide single nucleotide polymorphism (SNP)-based investigation on bipolar disorder (BD) that focuses on an important aspect of disease course, the functional outcome. FIERS identified a significantly associated locus on chromosome 15 (hg38: chr15:48965004 – 49464789 bp) with consistent effect strength between two independent studies (GAIN/TGen: European Americans, BOMA: Germans; n = 1592 BD patients in total). Protective and risk haplotypes were found on the most strongly associated SNPs. They contain a CTCF binding site (rs586758); CTCF sites are known to regulate sets of genes within a chromatin domain. The rs586758 – rs2086256 – rs1904317 haplotype is located in the promoter flanking region of the COPS2 gene, close to microRNA4716, and the EID1, SHC4, DTWD1 genes as plausible biological candidates. While implication with BD is novel, COPS2, EID1, and SHC4 are known to be relevant for neuronal differentiation and function and DTWD1 for psychopharmacological side effects. The test strategy FIERS that enabled this discovery is equally applicable for tag SNPs and sequence data.Item Fine mapping of bone structure and strength QTLs in heterogeneous stock rat(Elsevier, 2015-12) Alam, Imranul; Koller, Daniel L.; Cañete, Toni; Blázquez, Gloria; Mont-Cardona, Carme; López-Aumatell, Regina; Martínez-Membrives, Esther; Díaz-Morán, Sira; Tobeña, Adolf; Fernández-Teruel, Alberto; Stridh, Pernilla; Diez, Margarita; Olsson, Tomas; Johannesson, Martina; Baud, Amelie; Econs, Michael J.; Foroud, Tatiana; Department of Medicine, IU School of MedicineWe previously demonstrated that skeletal structure and strength phenotypes vary considerably in heterogeneous stock (HS) rats. These phenotypes were found to be strongly heritable, suggesting that the HS rat model represents a unique genetic resource for dissecting the complex genetic etiology underlying bone fragility. The purpose of this study was to identify and localize genes associated with bone structure and strength phenotypes using 1524 adult male and female HS rats between 17 to 20 weeks of age. Structure measures included femur length, neck width, head width; femur and lumbar spine (L3-5) areas obtained by DXA; and cross-sectional areas (CSA) at the midshaft, distal femur and femoral neck, and the 5th lumbar vertebra measured by CT. In addition, measures of strength of the whole femur and femoral neck were obtained. Approximately 70,000 polymorphic SNPs distributed throughout the rat genome were selected for genotyping, with a mean linkage disequilibrium coefficient between neighboring SNPs of 0.95. Haplotypes were estimated across the entire genome for each rat using a multipoint haplotype reconstruction method, which calculates the probability of descent at each locus from each of the 8 HS founder strains. The haplotypes were then tested for association with each structure and strength phenotype via a mixed model with covariate adjustment. We identified quantitative trait loci (QTLs) for structure phenotypes on chromosomes 3, 8, 10, 12, 17 and 20, and QTLs for strength phenotypes on chromosomes 5, 10 and 11 that met a conservative genome-wide empiric significance threshold (FDR=5%; P<3×10(-6)). Importantly, most QTLs were localized to very narrow genomic regions (as small as 0.3 Mb and up to 3 Mb), each harboring a small set of candidate genes, both novel and previously shown to have roles in skeletal development and homeostasis.Item Genetic and childhood trauma interaction effect on age of onset in bipolar disorder: An exploratory analysis(Elsevier, 2015-07-01) Anand, Amit; Koller, Daniel L.; Lawson, William B.; Gershon, Elliot S.; Nurnberger, John I.; Psychiatry, School of MedicineIntroduction This study investigated whether early life trauma mediates genetic effects on the age at onset (AAO) of bipolar disorder. Method Data from the BiGS Consortium case samples (N = 1119) were used. Childhood traumatic events were documented using the Childhood Life Events Scale (CLES). Interaction between occurrence of childhood trauma and common genetic variants throughout the genome was tested to identify single nucleotide polymorphic gene variants (SNPs) whose effects on bipolar AAO differ between individuals clearly exposed (CLES ≥ 2) and not exposed (CLES = 0) to childhood trauma. Results The modal response to the CLES was 0 (N = 480), but an additional 276 subjects had CLES = 1, and 363 subjects reported 2 or more traumatic lifetime events. The distribution of age at onset showed a broad peak between ages 12 and 18, with the majority of subjects having onset during that period, and a significant decrease in age of onset with the number of traumatic events. No single SNP showed a statistically significant interaction with the presence of traumatic events to impact bipolar age at onset. However, SNPs in or near genes coding for calcium channel activity-related proteins (Gene Ontology: 0005262) were found to be more likely than other SNPs to show evidence of interaction using the INRICH method (p < 0.001). Limitations Retrospective ascertainment of trauma and AAO. Conclusion Interaction effects of early life trauma with genotype may have a significant effect on the development and manifestation of bipolar disorder. These effects may be mediated in part by genes involved in calcium signaling.Item Genome-wide association study of serum iron phenotypes in premenopausal women of European descent(Elsevier, 2016-03) Koller, Daniel L.; Imel, Erik A.; Lai, Dongbing; Padgett, Leah R.; Acton, Dena; Gray, Amie; Peacock, Munro; Econs, Michael J.; Foroud, Tatiana; Department of Medical & Molecular Genetics, IU School of MedicineA genome-wide association study was performed in 1,130 premenopausal women to detect common variants associated with three serum iron-related phenotypes. Total iron binding capacity was strongly associated (p=10−14) with variants in and near the TF gene (transferrin), the serum iron transporting protein, and with variants in HFE (p= 4×10−7), which encodes the human hemochromatosis gene. Association was also detected between percent iron saturation (p=10−8) and variants in the chromosome 6 region containing both HFE and SLC17A2, which encodes a phosphate transport protein. No significant associations were detected with serum iron, but variants in HFE were suggestive (p=10−6). Our results corroborate prior studies in older subjects and demonstrate that the association of these genetic variants with iron phenotypes can be detected in premenopausal women.Item High-resolution genome screen for bone mineral density in heterogeneous stock rat(Wiley, 2014-07) Alam, Imranul; Koller, Daniel L.; Cañete, Toni; Blázquez, Gloria; López-Aumatell, Regina; Martínez-Membrives, Esther; Díaz-Morán, Sira; Tobeña, Adolf; Fernández-Teruel, Alberto; Stridh, Pernilla; Dieze, Margarita; Olsson, Tomas; Johannesson, Martina; Baud, Amelie; Econs, Michael J.; Foroud, Tatiana; Department of Medicine, IU School of MedicineWe previously demonstrated that skeletal mass, structure, and biomechanical properties vary considerably in heterogeneous stock (HS) rat strains. In addition, we observed strong heritability for several of these skeletal phenotypes in the HS rat model, suggesting that it represents a unique genetic resource for dissecting the complex genetics underlying bone fragility. The purpose of this study was to identify and localize genes associated with bone mineral density in HS rats. We measured bone phenotypes from 1524 adult male and female HS rats between 17 and 20 weeks of age. Phenotypes included dual-energy X-ray absorptiometry (DXA) measurements for bone mineral content and areal bone mineral density (aBMD) for femur and lumbar spine (L3-L5), and volumetric BMD measurements by CT for the midshaft and distal femur, femur neck, and fifth lumbar vertebra (L5). A total of 70,000 polymorphic single-nucleotide polymorphisms (SNPs) distributed throughout the genome were selected from genotypes obtained from the Affymetrix rat custom SNPs array for the HS rat population. These SNPs spanned the HS rat genome with a mean linkage disequilibrium coefficient between neighboring SNPs of 0.95. Haplotypes were estimated across the entire genome for each rat using a multipoint haplotype reconstruction method, which calculates the probability of descent for each genotyped locus from each of the eight founder HS strains. The haplotypes were tested for association with each bone density phenotype via a mixed model with covariate adjustment. We identified quantitative trait loci (QTLs) for BMD phenotypes on chromosomes 2, 9, 10, and 13 meeting a conservative genomewide empiric significance threshold (false discovery rate [FDR] = 5%; p < 3 × 10(-6)). Importantly, most QTLs were localized to very small genomic regions (1-3 megabases [Mb]), allowing us to identify a narrow set of potential candidate genes including both novel genes and genes previously shown to have roles in skeletal development and homeostasis.Item Identification of pathways for bipolar disorder: a meta-analysis(AMA, 2014-06) Nurnberger, John I. Jr.; Koller, Daniel L.; Jung, Jeesun; Edenberg, Howard J.; Foroud, Tatiana; Guella, Ilaria; Vawter, Marquis P.; Kelsoe, John R.; Medical & Molecular Genetics, School of MedicineIMPORTANCE: Genome-wide investigations provide systematic information regarding the neurobiology of psychiatric disorders. OBJECTIVE: To identify biological pathways that contribute to risk for bipolar disorder (BP) using genes with consistent evidence for association in multiple genome-wide association studies (GWAS). DATA SOURCES: Four independent data sets with individual genome-wide data available in July 2011 along with all data sets contributed to the Psychiatric Genomics Consortium Bipolar Group by May 2012. A prior meta-analysis was used as a source for brain gene expression data. STUDY SELECTION: The 4 published GWAS were included in the initial sample. All independent BP data sets providing genome-wide data in the Psychiatric Genomics Consortium were included as a replication sample. DATA EXTRACTION AND SYNTHESIS: We identified 966 genes that contained 2 or more variants associated with BP at P < .05 in 3 of 4 GWAS data sets (n = 12,127 [5253 cases, 6874 controls]). Simulations using 10,000 replicates of these data sets corrected for gene size and allowed the calculation of an empirical P value for each gene; empirically significant genes were entered into a pathway analysis. Each of these pathways was then tested in the replication sample (n = 8396 [3507 cases, 4889 controls]) using gene set enrichment analysis for single-nucleotide polymorphisms. The 226 genes were also compared with results from a meta-analysis of gene expression in the dorsolateral prefrontal cortex. MAIN OUTCOMES AND MEASURES: Empirically significant genes and biological pathways. RESULTS Among 966 genes, 226 were empirically significant (P < .05). Seventeen pathways were overrepresented in analyses of the initial data set. Six of the 17 pathways were associated with BP in both the initial and replication samples: corticotropin-releasing hormone signaling, cardiac β-adrenergic signaling, phospholipase C signaling, glutamate receptor signaling, endothelin 1 signaling, and cardiac hypertrophy signaling. Among the 226 genes, 9 differed in expression in the dorsolateral prefrontal cortex in patients with BP: CACNA1C, DTNA, FOXP1, GNG2, ITPR2, LSAMP, NPAS3, NCOA2, and NTRK3. CONCLUSIONS AND RELEVANCE: Pathways involved in the genetic predisposition to BP include hormonal regulation, calcium channels, second messenger systems, and glutamate signaling. Gene expression studies implicate neuronal development pathways as well. These results tend to reinforce specific hypotheses regarding BP neurobiology and may provide clues for new approaches to treatment and prevention.