''Does bipolar disorder accelerate cellular aging? A systematic review and meta-analysis of telomere length''

Recent research has suggested that bipolar disorder (BD) might be associated with accelerated aging. Multiple studies have shown telomere shortening in BD but others did not support this notion. In BD, TL can be influenced by factors such as aging, smoking, metabolic syndrome, the nature of the disorder, and lithium use. To evaluate differences in TL between individuals with BD and healthy controls and to explore potential factors influencing telomere shortening, we conducted a meta-analysis of studies comparing these populations.

A systematic literature search was conducted in PubMed and Scopus databases up to November 2024. Original research articles reporting TL measures were selected.

A total of 24 studies, including 2330 patients diagnosed with BD and 2912 healthy controls, were included in the analysis. TL was significantly shorter in patients with BD compared to controls (Hedges' g, -0.42; 95% CI, -0.6 to -0.21; p <0.001). Meta-regression analyses showed that between-group differences in body mass index (BMI) had a significant effect on effect size. No statistically significant differences were found in subgroup analyses according to lithium use, duration of illness, telomere measurement method, substance use exclusion criteria, study quality, and euthymia. A moderate negative correlation was observed between age and TL in both BD and control groups ( r=-0.38, r=-0.37).

Our results support the presence of illness-associated cellular aging in BD. Longitudinal studies with repeated TL measurements are needed to examine the potential effects of disease course, aging, illness duration, and medication on this process.