Population ageing is poised to become “one of the most significant social transformations of the 21st century”, affecting nearly all sectors of society, including family structures, labour and financial markets, as well as the demand for goods and services, according to a recent United Nations global issues report.
In addition, a 2016 report from a Washington DC thinktank, the Brookings Institute, calls it “an irreversible global trend with far-reaching economic and socio-political consequences”.
By 2050, the report says, the number of people aged 60 and older will more than double from its current levels, to about two billion.
Clearly, then, understanding the healthcare needs of this growing population is vital and will gain in importance as the trend gathers momentum.
Now, a new study into the mental health of seniors has found links between the onset of late-life depression, walking speed, and pace length.
The report, published in the Journal of the American Geriatrics Society, says older people who were newly diagnosed with depression had a slower walking speed and a shorter step length, compared to those without the condition.
A team of researchers from the Irish Longitudinal Study on Ageing, based at Trinity College in Dublin, Ireland, and the Mercer’s Institute for Successful Ageing, at St James’s Hospital, also in Dublin, worked with more than 3600 people aged 50 and over, who had not previously been diagnosed as having depression.
The study’s lead author, Robert Briggs, says depression in older people is difficult to diagnose because they are much less likely to consult healthcare professionals concerning mood-related symptoms.
“These findings are important because it is crucial to identify older individuals at higher risk of developing depression in order to promote earlier intervention,” he says.
Briggs says the study also suggests that exercise programs aimed at improving walking speed and balance may help prevent the onset of depression in later life, “though this would need to be tested in dedicated clinical studies”.
The researchers used the GAITRite system, a computerised mat with pressure sensors, to analyse walking styles, or gaits.
Participants started walking 2.5 metres before the mat and stopped two metres after it, to allow for acceleration and deceleration. They completed two walks in each of three conditions: at a usual walking pace, walking while carrying out a manual task (in this case, holding a glass of water), and walking while carrying out a cognitive task (such reciting alternate letters of the alphabet).
Data from walks in each condition were averaged to arrive at information for gait speed, step length, step width and other actions.
The report says gait disorders affect about a third of community-dwelling people aged 60 or older, increasing significantly with age. Given the wide range of processes that are required to maintain gait and balance, it says, there are many potential causes of these disorders, including osteoarthritis, and neurological problems such as stroke, Parkinson’s disease or multiple sclerosis.
There are also factors that cannot be explained by demonstrable deficiencies, but the report says a decline in gait is a “consistent and reliable predictor of future functional status and mortality in later life”.
“Gait problems, particularly higher-level gait problems, are also closely linked with poorer brain health outcomes, increasing the risk of incident dementia, particularly vascular dementia,” the report says.
There is also growing evidence linking gait disturbance with depression in later life, the researchers write, with symptoms associated with slower gait speed and shorter stride length.
Late-life depression is also associated with an increased risk of falls, which may be related to gait disturbance.
Briggs and colleagues say their findings are significant because they may help medical professionals unravel and understand associations between common late-life conditions that affect the lives of millions of people.
“Both depression and gait problems commonly coexist in later life, and it appears that older people with a combination of both conditions are at particularly high risk of functional decline,” they conclude.