The conclusion was that people who had committed suicides had significantly shorter telomeres than healthy controls. This pattern was visible in young people (aged 34 and younger) and middle-aged women (35-59) but no longer apparent for elderly people, likely because telomeres shorten as we age. In white blood cells, the length of telomeres ranges from 8,000 base pairs in newborns to 3,000 base pairs in adults and as low as 1,500 in elderly people.
They also found mtDNAcn was significantly higher in those who committed suicide. Oddly, this pattern held true for elderly people but not for young or middle-aged participants. Young people have higher levels of mtDNAcn.
When the brain samples alone were considered, both telomere length and mtDNAcn were lower among people who committed suicide.
The results seem a bit contradictory but they at least suggest a trend where biology is linked to suicidal events. Further studies might be able to shed light in broader detail. If they can confirm the findings, telomere length could serve as a biomarker for the risk of suicide.
“In conclusion, we report the first association of aberrant telomeres and mtDNAcn with suicide completion. Our results raise the possibility that further research into telomere shortening and mtDNA dysfunction may elucidate the molecular underpinnings of suicide-related pathophysiology,” the authors wrote.
Journal Reference: Ikuo Otsuka, et al. “Aberrant telomere length and mitochondrial DNA copy number in suicide completers.” Scientific Reports 7, Article number: 3176. Published: 9-June-2017. doi:10.1038/s41598-017-03599-8