Telomere length predicts lifespan.   Now, a new study has shown an association between childhood trauma, shortened telomere length and mental illness such as bipolar mood disorder and schizophrenia. Hmmm…  What’s that telling us?

mental illness

DNA Transcription

Cell division is essential to life and telomeres are part of that process.  Telomeres form protective caps on the end of strands of DNA. Repetitive sequences of nucleotides make up telomeres. Like the plastic tips on the end of shoelaces, telomeres protect chromosomes from damage while cell division takes place. They also prevent the end of the chromosome fusing with other chromosomes.

Each time cell division occurs, your telomeres get shorter.  This shortening happens because DNA polymerases, the enzymes that duplicate DNA, cannot copy all the way to the end of a chromosome.  After every duplication, the tip of the chromosome gets shorter.

Eventually, a limit is reached when the telomere is too short and cell division is no longer possible. This is the Hayflick Limit.  A normal human cell can only replicate and divide some 40 to 60 times. Once the Hayflick Limit is reached, the cell it is destroyed by apoptosis.

Chromosomes capped by telomeres, the small bright dots on the ends. (Credit: / U.S. Department of Energy)

Telomerase, an enzyme, comes to the rescue. It offsets the shortening of telomeres by splicing telomeric DNA (T2AG3 repeats) onto the ends of the telomere. That increases the length and counteracting the shrinkage caused by cellular replication.   

The Good, the Bad & the Ugly

Now, you shouldn’t think that the shortening of telomeres is necessarily all bad.  After all, our genetic blueprint functions in such a way that our cells die off naturally.  When this process goes awry, one potential consequence is cancer.  In many types of cancer, telomere length is maintained by telomerase.  Cancer cells attain a kind of immortality because the natural process of dying off due to telomere shortening does not take place.  Interestingly, some cancer treatments now specifically targeted telomerase.

Given these various facts, is not surprising that telomere length has been proposed as a proxy for cellular ageing, although the concept is arguably in need of refinement.  Telomere length is indeed linked to lifespan, at least in zebra finches who don’t live for very long and are therefore convenient to study when investigating lifespan.  Researchers have shown that telomere length early in life is a very strong predictor of longevity. Personally, I think that is amazing!

An Expansive Vision on Mental Illness

A landmark study published in 2004 showed that psychological stress is linked to shortened telomere length, reduced telomerase activity and higher oxidative stress. This research broadened the focus from physical illnesses such as cancer, diabetes and cardiac disease to include the relationship between mental well-being, cellular replication, and telomere length. 

Telomeres & Mental Illness: Schizophrenia and Bipolar Mood Disorder

A recent study investigated childhood trauma in mental illness patients with a diagnosis of schizophrenia or bipolar mood disorder.  Compared to healthy controls, telomere length was shorter in the patients with mental illness and they reported more childhood trauma than controls.  Patients who had a history of childhood abuse, be it emotional, physical or sexual abuse, had shorter telomeres than healthy controls and patients who had no history of childhood abuse. 

Image of a teddy bear that alludes to abuse

Thus, a specific effect associated with shortened telomere length arises from emotional, physical or sexual abuse in childhood.  In that regard, it is relevant that abuse is a particularly stressful experience.  One characteristic feature of abuse is the experience of being out of control, of being unable to do anything to change the situation.  That belief is particularly psychologically damaging.  In the long-term, the experience of being unable to influence a stressful situation may cause structural changes in the brain. That said, in this study there was no association between telomere length and brain morphology.

A recent meta-analysis examined the relationship between perceived stress and telomere length. The researchers identified a statistically significant relationship between perceived stress and telomere length after adjusting for age.  The age adjustment is important because telomere length systematically shortens as we get older.

Long Life

The good news is that robust research has shown that it is possible to turnaround cellular ageing and increase telomere length through a programme of comprehensive lifestyle changes that target diet, exercise, stress management, psychotherapy and social support.  Let’s put that into different words: love, good friends, healthy food, and some exercise will go a long way to solving your emotional problems and simultaneously lengthen your telomeres and give you long life!!

Image of a happy family, jumping for joy, with a kitsch sunset in the background.


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