Heritability and linkage analysis of personality in bipolar disorder

• Published in: Journal of affective disorders Vol. 151; no. 2; pp. 748 - 755
• Main Authors: Greenwood, Tiffany A, Badner, Judith A, Byerley, William, Keck, Paul E, McElroy, Susan L, Remick, Ronald A, Dessa Sadovnick, A, Kelsoe, John R
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 01.11.2013; Elsevier
• Subjects: Adult; Adult and adolescent clinical studies; Biological and medical sciences; Bipolar affective disorder; Bipolar disorder; Bipolar Disorder - genetics; Bipolar Disorder - psychology; Bipolar disorders; Chromosomes; Depressive Disorder, Major - genetics; Endophenotypes; Family; Female; Genes; Genetic Linkage; Genetic Predisposition to Disease; Genome-Wide Association Study; Genotype; Heritability; Humans; Male; Medical sciences; Middle Aged; Miscellaneous; Mood disorders; Personality; Personality - genetics; Personality disorders; Personality Inventory; Phenotypes; Polymorphism, Single Nucleotide; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; TCI; Temperament; Bipolar disorder; Personality; Heritability; TCI; Genetic linkage; Mood disorder; Genetics; Genetic determinism; Personality disorder
• ISSN: 0165-0327; 1573-2517
• DOI: 10.1016/j.jad.2013.06.015

Abstract Background The many attempts that have been made to identify genes for bipolar disorder (BD) have met with limited success, which may reflect an inadequacy of diagnosis as an informative and biologically relevant phenotype for genetic studies. Here we have explored aspects of personality as quantitative phenotypes for bipolar disorder through the use of the Temperament and Character Inventory (TCI), which assesses personality in seven dimensions. Four temperament dimensions are assessed: novelty seeking (NS), harm avoidance (HA), reward dependence (RD), and persistence (PS). Three character dimensions are also included: self-directedness (SD), cooperativeness (CO), and self-transcendence (ST). Methods We compared personality scores between diagnostic groups and assessed heritability in a sample of 101 families collected for genetic studies of BD. A genome-wide SNP linkage analysis was then performed in the subset of 51 families for which genetic data was available. Results Significant group differences were observed between BD subjects, their first-degree relatives, and independent controls for all but RD and PS, and all but HA and RD were found to be significantly heritable in this sample. Linkage analysis of the heritable dimensions produced several suggestive linkage peaks for NS (chromosomes 7q21 and 10p15), PS (chromosomes 6q16, 12p13, and 19p13), and SD (chromosomes 4q35, 8q24, and 18q12). Limitations The relatively small size of our linkage sample likely limited our ability to reach genome-wide significance in this study. Conclusions While not genome-wide significant, these results suggest that aspects of personality may prove useful in the identification of genes underlying BD susceptibility.