Madia Lozupone, MD, PhD

The age of onset of depression for patients with late-life depression (LLD) is important for calculating the risk of all-cause mortality, according to new research.

A team, led by Madia Lozupone, MD, PhD, Neurodegenerative Disease Unit, Department of Basic Medicine, Neuroscience, and Sense Organs, University of Bari Aldo Moro, evaluated the risk of all-cause mortality of older patients with late-life depression and its subtypes and examined whether inflammatory, cognitive, genetic features, and multimorbidity could modify the effect of the association.

Late-Life Depression

Late-life depression is associated with a shorter survival. However, there is not a lot of research in population-based settings about health-related outcomes of different late-life depression subtypes, including early-onset depression (EOD) and late-onset depression (LOD).

In the longitudinal population-based study, the investigators looked at data from 1479 individuals aged 65 years and old in the Salus in Apulia Study, which includes 19,675 total participants, 4021 of which were aged 65 years and older.

The investigators also obtained mortality data from the electronic health records.

Each participants was diagnosed with late-life depression through the DSM-IV-TR criteria, as well as early-onset depression and late-onset depression based on the age of onset. The investigators also defined multimorbidity status as the copresence of 2 or more chronic diseases.

Prevalence of Disease

The results show an overall prevalence of late-life depression of 10.2% in Southern Italy. In addition, 3.4% (n = 50) of the population had early-onset depression and 6.8% (n = 101) had late-onset depression.

After using a multivariable Cox model that was adjusted for age, gender, education, global cognition, apolipoprotein E ε4 allele, physical frailty, interleukin-6, and multimorbidity, the investigators found late-life depression resulted in a greater risk of all-cause mortality.

This shows that late-life depression was more common in women (n = 95; 62.9%).

However, there were differences found between the 2 different age of onset groups in gender, education, cognitive dysfunctions, and diabetes mellitus.

There was also a significantly increased risk for participants with late-onset depression for all-cause mortality (HR, 1.99; 95% CI, 1.33-2.97) in the time of observation between enrollment date and death date (7.31 ± 2.17 months).

After stratifying the diagnosis for the different subtypes, only late-onset depression contributed to the association of all-cause mortality.This essentially doubled the risk of death and individuals with late-onset depression died on average 1 year earlier than participants with early-onset depression and people without late-life depression.

“In older age, the appearance of depression for the first time may be more detrimental than its re-appearance in previously affected individuals,” the authors wrote. “LLD may be the consequence of the synergistic effect of the aging process and some chronic diseases such as diabetes mellitus, that share some of the changes accompanying senescence, mainly those related to oxidative stress, low-grade inflammation, and insulin resistance.”

The study, “Late-Onset Depression But Not Early-Onset Depression May Increase the Risk of All-cause Mortality in Older Age: 8-year Follow-up of the Salus in Apulia Study,” was published online in the Journal of the American Medical Directors Association.