The load of short telomeres is increased and associated with lifetime number of depressive episodes in bipolar II disorder

• Published in: Journal of affective disorders 2011-12, Vol.135 (1), p.43-50
• Main Authors: Elvsåshagen, Torbjørn, Vera, Elsa, Bøen, Erlend, Bratlie, Jorunn, Andreassen, Ole A, Josefsen, Dag, Malt, Ulrik F, Blasco, Maria A, Boye, Birgitte
• Format: Article
• Language: English
• Subjects: Adult; Adult and adolescent clinical studies; Affective disorders; Ageing; Aging; Aging - genetics; Biological and medical sciences; Biological markers; Bipolar affective disorder; Bipolar Disorder - genetics; Bipolar Disorder - psychology; Bipolar disorders; Case-Control Studies; Cross-Sectional Studies; Depression; Depression - genetics; Depression - psychology; Depressive Disorder - genetics; Depressive episode; Diagnostic and Statistical Manual of Mental Disorders; Dysfunction; Female; Humans; In Situ Hybridization, Fluorescence; Leukocytes, Mononuclear; Load of short telomeres; Longitudinal Studies; Male; Medical sciences; Mental Disorders - genetics; Mood disorders; Psychiatric disorders; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Telomere; Telomere length; Telomere Shortening; Time Factors
• ISSN: 0165-0327; 1573-2517
• DOI: 10.1016/j.jad.2011.08.006

Abstract Background It has recently been hypothesized that bipolar disorders are associated with accelerated aging. Telomere dysfunction, a biomarker of aging, is determined by the load of short telomeres, rather than by the mean telomere length. To our knowledge, the load of short telomeres has not been reported in any psychiatric disorder. The aims of the study were to examine the load of short telomeres and the mean telomere length and their relationships with illness duration and lifetime number of depressive episodes in bipolar II disorder (BD-II). Methods Twenty-eight patients (mean age = 34.8 ± 7.7) with a DSM-IV diagnosis of BD-II and 28 healthy control subjects (mean age = 34.8 ± 9.2) matched for age, sex, and education participated. The load of short telomeres (percentage of telomeres < 3 kilobases) and mean telomere length in peripheral blood mononuclear cells were measured using high-throughput quantitative fluorescence in situ hybridization. Results The load of short telomeres was significantly increased in patients with BD-II relative to healthy controls and may represent 13 years of accelerated aging. The load of short telomeres and the mean telomere length were associated with lifetime number of depressive episodes, but not with illness duration. Limitations Modest sample size and cross-sectional design. Conclusions Our results suggest that BD-II is associated with an increased load of short telomeres. Depressive episode-related stress may accelerate telomere shortening and aging. However, longitudinal studies are needed to fully clarify telomere shortening and its relationship with clinical variables in BD-II.