Anxiety May Speed Aging

Megan Brooks

February 09, 2015

Anxiety disorders may contribute to shorter telomere length, a known marker of aging. However, adequate treatment may help reverse the process, new research suggests.

Results from a large study showed that patients with a current anxiety disorder had shorter telomeres than nonpsychiatric control individuals and those with remitted anxiety disorder, suggesting that telomere shortening can be reversed with adequate treatment of an anxiety disorder.

"In the Netherlands Study of Depression and Anxiety, we had the opportunity to look at telomere length in over 2300 persons with and without anxiety disorders. Our results show that persons with a current anxiety disorder on average had shorter telomere length, although cause and effect remain to be explored," first author Josine Verhoeven, from the Department of Psychiatry and the EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, the Netherlands, told Medscape Medical News.

The study was published online February 5 in the British Journal of Psychiatry.

Accelerated Aging

Telomeres are specialized DNA complexes that cap the ends of chromosomes and that shorten with age. They are considered an indicator of cellular aging.

Some recent studies have shown an association between depression and shorter telomere length, but it remains unclear whether a similar association exists for anxiety disorders.

The analysis included 1283 adults with a current anxiety disorder, 459 with a remitted anxiety disorder, and 582 control individuals with no psychiatric disorder. The mean age of the entire cohort was 41.7 years, and 66% were women.

Anxiety disorders included generalized anxiety disorder, social phobia, agoraphobia, and panic disorder with and without agoraphobia. Leukocyte telomere length (LTL) was assessed using quantitative polymerase chain reaction and converted into base pairs (bp).

LTL showed a significant negative correlation with age corresponding to an average shortening rate of 14 bp/year. Women had longer LTL than men.

In addition to age and sex, LTL also correlated with several lifestyle factors, including weight (shorter LTL in underweight, overweight, or obese individuals), smoking and drinking status (former and current smokers and heavy drinkers have shorter LTL), and number of somatic diseases (more diseases, shorter LTL).

After adjusting for sociodemographic, health, and lifestyle factors, patients with a current anxiety disorder had significantly shorter LTL compared with control patients (bp 5431 vs bp 5506; P = .01) and patients with remitted anxiety disorder (bp 5499; P = .03).

In the fully adjusted model, LTL was shorter on average by 75 bp in patients with a current anxiety disorder compared with control patients (P = .01) and 68 bp shorter (P = .03) compared with the remission group.

"Although the effect sizes were modest, the difference may indicate 3 to 5 years of accelerated aging for the current anxiety group, based on the estimated mean telomere shortening rate of 14 to 20 bp/year," the researchers report.

Clinical Implications?

The differences in LTL for the anxiety subgroups corresponded to an estimated 3.5 to 5 years (social phobia), 4 to 6 years (panic disorder with agoraphobia), and 5.5 to 8 years (generalized anxiety disorder) of accelerated aging compared with the nonpsychiatric control group.

LTL length was not significantly different in the remitted anxiety group and the control group (P = .84). However, time since remission was positively related with LTL. Those with a remission time of less than 10 years had shorter telomeres than those who had been in remission for 10 years or longer (P = .022), suggesting that the cellular aging process is in part reversible, the researchers note.

The investigators also found that anxiety severity scores were negatively associated with LTL in the whole sample, which supports a dose-response association.

The biological mechanisms behind the observed association between anxiety disorders and telomere shortening, as well as the direction of the link, require further study, they note.

Shorter LTL might be a consequence of disturbances in the body's stress systems, seen in people with anxiety disorders.

"In line with this, several in vitro and in vivo studies found increased cortisol, oxidative stress and proinflammatory cytokines to be associated with shorter telomere length," they write. Recovering from an anxiety disorder could normalize bodily stress systems.

"There are no direct clinical implications of the finding yet," said Dr Verhoeven. "However, future research could investigate whether certain interventions are able to have an impact not only the psychiatric symptoms but also on physiology."

She noted that lifestyle interventions such as increased physical activity have been shown to have a favorable impact on telomere length in a healthy population.

"We are currently executing an intervention to investigate the effects of antidepressive medication or running therapy on both psychiatric and somatic health, including telomere length and telomerase activity," Dr Verhoeven said.

Interesting Findings

Mikael Wikgren, PhD, from the Division of Psychiatry, Umeå University, in Sweden, has studied telomere length in relation to depression. He noted that the Dutch study is "interesting [and] expands upon and corroborates earlier study suggesting accelerated telomere length shortening in anxiety disorders."

"Particularly interesting," Dr Wikgren said, "are the findings showing that individuals with remitted anxiety disorders did not differ in telomere length compared with healthy controls. Does this suggest that telomere length can be recovered, when the negative burden of anxiety is lifted?

"Is it an effect of treatment? Or does it reflect some protective factor in individuals within the group with remitted anxiety disorder, also preventing accelerated telomere erosion? Further studies, preferably longitudinal, are needed to elucidate how, and when, this difference arises," Dr Wikgren said.

The authors' disclosures can be found in the original article.

Br J Psychiatry. Published online February 5, 2015. Abstract

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