RESEARCH conducted at Kings College London, London, UK and Icahn School of Medicine, Mount Sinai, New York City, New York, USA has shown a link between shortened telomere length and bipolar disorder risk. Telomere length is commonly associated with biological ageing.
Bipolar disorder affects ~2.6% of adults in the USA each year, with symptoms such as changes in mood, from extremely euphoric, to despairing and depressed. Bipolar disorder is also linked with other diseases which are usually associated with old age, including cardiovascular disease, Type 2 diabetes mellitus, and obesity. The research team set out to assess this association, with specific reference to telomeres. Previous research has connected shortened telomeres with major depressive disorder, schizophrenia, and dementia.
During the investigation, 63 bipolar disorder patients, 74 first-degree relatives, and 80 unrelated healthy individuals were studied. Results showed that the telomere length of first-degree relatives was notably shorter than the healthy controls. Telomere length is heritable, thus these results were expected to some degree. Interestingly, the length of the bipolar cohort telomeres was dependent on whether they were taking lithium, a drug commonly used to treat bipolar disorder. Individuals taking lithium did not have significantly shorter telomeres; whereas those who not treated with lithium showed the same reduction as their relatives, suggesting that lithium minimises premature ageing associated with bipolar disorder.
Further investigations were carried out to assess the relationship between telomere length and brain structure. Magnetic resonance imaging (MRI) scans showed shorter telomeres were associated with reduced hippocampal volume, the area of the brain associated with memory and mood regulation.
First author Dr Timothy Powell, Kings College London commented that the study “provides the first evidence that familial risk for bipolar disorder is associated with shorter telomeres”, explaining that this may be the reason why bipolar patients are at a greater risk of ageing-related diseases. Whilst opening further avenues of research, co-senior author Dr Sophia Frangou, Icahn School of Medicine, said that the results suggest “that proteins which protect against telomere shortening may provide novel treatment targets for people with bipolar disorder and those predisposed to it.”