A reduced ability to feel pleasure, known as anhedonia, is one symptom of depression. Familiar pleasures, such as listening to music or spending time with friends, may no longer feel as enjoyable. In a study of 440 women, this symptom was associated with a higher-than-expected biological-age estimate in monocytes, white blood cells that help defend the body. The Journals of Gerontology: Series A (source, opens in new tab)The Journals of Gerontology: Series AMonocyte epigenetic age acceleration is linked to non-somatic depressive symptoms in women with and without HIVOpen source (opens in new tab)
The researchers estimated the cells’ biological age from patterns of chemical marks on DNA, known as DNA methylation. This gives an indication of how old the cells appear biologically compared with the woman’s actual age. They used existing data to calculate these estimates, rather than following cells as they aged.
They then compared these age estimates with women’s answers to a questionnaire about depressive symptoms. Monocytes that appeared older than expected were associated with symptoms affecting feelings and thinking, which the study called “non-somatic” symptoms. The researchers also found a link with anhedonia specifically. The study cannot establish cause and effect.
The women took part in the Women’s Interagency HIV Study. Of the 440 participants, 261 had HIV and 179 did not. In the combined group, the links with non-somatic symptoms and anhedonia remained after the researchers accounted for HIV status, race and ethnicity.
The researchers also tested whether a broader estimate of biological age showed similar links. They compared their monocyte-specific measure with the Horvath clock, a method that estimates age from DNA-methylation patterns across multiple tissue types. The broader clock was not associated with overall depression severity or any of the symptom groups examined. The link appeared with the measure tailored to monocytes.
When the researchers looked separately at women with HIV, the association with non-somatic symptoms did not reach statistical significance. The result from the combined group therefore does not establish the same relationship among women with HIV. NYU Rory Meyers College of Nursing (source, opens in new tab)
NYU Rory Meyers College of NursingMarker of Biological Aging Linked to Some, Not All, Symptoms of DepressionOpen source (opens in new tab)
The finding gives researchers a reason to examine specific immune cells alongside individual depressive symptoms. The authors describe monocyte ageing as a potential marker—a biological clue to investigate, not a clinical test for depression.
- The Journals of Gerontology: Series A · Peer-reviewed studyMonocyte epigenetic age acceleration is linked to non-somatic depressive symptoms in women with and without HIVacademic.oup.com · opens in new tab
- NYU Rory Meyers College of Nursing · InstitutionMarker of Biological Aging Linked to Some, Not All, Symptoms of Depressionnursing.nyu.edu · opens in new tab
