Summary: The proportion of those aged 65 and older prescribed antidepressants has more than doubled over two decades, from 4.2% in the 90s to 10.7% in twenty years later. However, the prevalence of depression among the age group has dropped since the 90s from 7.9% to 6.8%.
Source: University of East Anglia
The proportion of people aged over 65 on antidepressants has more than doubled in two decades – according to new research led by the University of East Anglia.
Despite a rise in antidepressant use, there was little change in the number of older people diagnosed with depression.
The findings are based on the Cognitive Function and Ageing Studies, conducted at two-time points – between 1991 and 1993, and between 2008 and 2011.
Researchers interviewed more than 15,000 over 65s in England and Wales to see whether the prevalence of depression and antidepressant use is changing.
Lead author Prof Antony Arthur, from UEA’s School of Health Sciences, said: “Depression is a leading cause of poor quality of life worldwide and we know that older people may be less likely than other age groups to go to their GP with symptoms of depression.
“Until now, little was known about how the relationship between the prevalence of depression and antidepressant use among older people has changed over time. The Cognitive Function and Ageing Studies led by the University of Cambridge have the ability to exam changes in the health needs of older people across generations based on random sampling and diagnostic methods held constant over time.
“We asked participants about their health, daily activities, use of health and social care services, and the medications they were taking.
“We used a standardised interview process to ascertain the presence or absence of symptoms of depression and then applied diagnostic criteria to see whether the participant was considered to have ‘case level’ depression, a level of depression more severe than that characterised by minor mood symptoms, such as loss of energy, interest or enjoyment.”
The study’s lead investigator Prof Carol Brayne, director of the Cambridge Institute of Public Health, said: “Our research has previously shown a dramatic age-for-age drop in dementia occurrence across generations. This new work reveals that depression has not shown the same reduction even in the presence of dramatically increased prescribing, itself not without concern given potential adverse effects we have also shown that are associated with polypharmacy.”
The proportion of older people receiving anti-depressant medication more than doubled over two decades – from 4.2 percent in the early nineties to 10.7 percent 20 years later.
The estimated prevalence of depression among over 65s in the early 1990s was 7.9 percent, compared to 6.8 percent 20 years later.
Depression and antidepressant use was more common in women than men at both time points.
Depression was associated with living in a more deprived area.
The proportion of over 65s living in care homes declined, but prevalence of depression in care homes remained unchanged – affecting around one in ten residents.
Across both time periods, most people with case-level depression were not on antidepressants, while most of those on antidepressants did not have depression.
Prof Arthur said: “Depression affects one in 15 people aged over 65, and its impact is felt by the individual, their families and friends.
“Between two comparable samples interviewed 20 years apart (1990-93 and 2008-11) we found little change in the prevalence of depression, but the proportion of participants taking antidepressants rose from 4 percent to almost 11 percent. This could be due to improved recognition and treatment of depression, overprescribing, or use of antidepressants for other conditions.
“Whatever the explanation, substantial increases in prescribing has not reduced the prevalence of depression in the over-65 population. The causes of depression in older people, the factors that perpetuate it, and the best ways to manage it remain poorly understood and merit more attention.”
The research was led by the University of East Anglia in collaboration with the University of Cambridge, the University of Newcastle and the University of Nottingham.
‘Changing prevalence and treatment of depression among the over-65s over two decades: findings from the Cognitive Function and Ageing Studies’ is published in the British Journal of Psychiatry.
Changing prevalence and treatment of depression among older people over two decades
Background Depression is a leading cause of disability, with older people particularly susceptible to poor outcomes.
Aims To investigate whether the prevalence of depression and antidepressant use have changed across two decades in older people.
Method The Cognitive Function and Ageing Studies (CFAS I and CFAS II) are two English population-based cohort studies of older people aged ≥65 years, with baseline measurements for each cohort conducted two decades apart (between 1990 and 1993 and between 2008 and 2011). Depression was assessed by the Geriatric Mental State examination and diagnosed with the Automated Geriatric Examination for Computer-Assisted Taxonomy algorithm.
Results In CFAS I, 7635 people aged ≥65 years were interviewed, of whom 1457 were diagnostically assessed. In CFAS II, 7762 people were interviewed and diagnostically assessed. Age-standardised depression prevalence in CFAS II was 6.8% (95% CI 6.3–7.5%), representing a non-significant decline from CFAS I (risk ratio 0.82, 95% CI 0.64–1.07, P = 0.14). At the time of CFAS II, 10.7% of the population (95% CI 10.0–11.5%) were taking antidepressant medication, more than twice that of CFAS I (risk ratio 2.79, 95% CI 1.96–3.97, P < 0.0001). Among care home residents, depression prevalence was unchanged, but the use of antidepressants increased from 7.4% (95% CI 3.8–13.8%) to 29.2% (95% CI 22.6–36.7%).
Conclusions A substantial increase in the proportion of the population reporting taking antidepressant medication is seen across two decades for people aged ≥65 years. However there was no evidence for a change in age-specific prevalence of depression.