Alarming Overprescription Patterns for Older Adults on Antidepressants

A new study finds polypharmacy for 73% of older adults on antidepressants, with 56% at risk of harmful drug interactions.


A new study that will soon be published in General Hospital Psychiatry found that many older adults who take antidepressants are also prescribed multiple other medications simultaneously, known as polypharmacy. In fact, the study showed that 73% of these older adults were prescribed multiple medications. Additionally, more than half of these patients were prescribed other drugs that could potentially cause problems when combined with their antidepressants, referred to as potentially inappropriate medications (PIMs).

The researchers also found that certain factors made it more likely for an older adult to be prescribed multiple medications, such as being older, unmarried, living in a rural area, having a non-western background, or having physical illnesses. However, having a history of using antidepressants or having a psychiatric diagnosis did not necessarily make it more likely for someone to be prescribed multiple medications.

This study highlights the importance of being aware of the potential risks of polypharmacy, especially in older adults, and the need for healthcare providers to consider the medications they prescribe to their patients carefully. The authors explain:

“A high prevalence of concurrent use of polypharmacy with antidepressants and PIMs with antidepressants was observed with a proportion of 73% and 56%, respectively. Socially disadvantaged and physically and mentally vulnerable older adults appeared more likely to have polypharmacy and PIMs use with antidepressants.”

According to the authors, nearly 1 in 10 older adults deals with depressive symptoms. Antidepressants are commonly the first line of treatment for such patients. Additionally, many of these older adults also have other physical and mental health issues for which drugs are often prescribed. As a result, many older adults take multiple medications at once, which increases the likelihood of PIMs. The current work aimed to examine polypharmacy and PIM in adults aged 65 and older.

The authors examined Denmark’s Civil Registration System data to accomplish this goal. This system collects demographic and healthcare information on everyone born, alive, or residing in the country. For the current study, the authors looked at adults aged 65 and over that redeemed a prescription for antidepressants at a Danish community pharmacy between January 1st, 2015, and December 31st, 2019 (n = 261,479).

The authors used this data to determine when older adults were given multiple prescriptions in addition to antidepressants and to determine when individuals may have been given drugs with dangerous interactions. The authors also looked at demographic information such as sex, age group, education, marital status, ethnicity, place of residence, etc., to determine if any of this information was predictive of polypharmacy and PIMs.

Overall, 73% of the individuals examined were prescribed multiple medications (using at least five concurrent drugs) and antidepressants. However, some subgroups were more at risk for polypharmacy than others, including older adults (83% in those over 86 years old), people with somatic and psychiatric diagnoses (93% in those with a high comorbidity score), and people with higher numbers of hospital visits (87% in those with three or more somatic hospital contacts within the past year).

Overall, 56% of the individuals examined were prescribed PIMs while taking antidepressants. 33% were prescribed at least one drug that could have dangerous interactions with their antidepressants, and 23% were prescribed more than 1. PIMs were most associated with those of older age (81-85 years old), short or medium educational attainment, widowed/separated/single marital status, rural residence, non-western ethnicity, and somatic hospital visits and diagnoses. The authors note that the prescription of PIMs decreased during the period they examined (2015-2019).

The authors acknowledge several limitations to the current work. First, they defined concurrent medication use as medications with at least a 1-day overlap, which could lead to overestimation. Second, the data they used only indicated that people had filled various prescriptions, not that they had taken the prescribed drugs. Third, the authors had no data on medications administered in hospitals or sold over the counter at pharmacies and so could have missed some instances of polypharmacy and PIMs. Fourth, it was not possible to determine the severity of symptoms in the population examined. There may be significant differences in polypharmacy and PIM based on severity that the current work could not address.

Lastly, 25% of the population examined in the current study used antidepressants for the first time. First-time users may have significant differences in terms of concurrent medication use, depression treatment, and comorbidities. The present study’s population was overwhelming Danish and white, drastically limiting generalizability to other people.

The authors conclude:

“The high use of polypharmacy and PIMs concurrently with antidepressants primarily reflects the presence of high comorbidity with depression in older adults. However, these markers underline a need for thorough examinations of the medical records of older patients and regular checking of the continued treatment indication and relevance of each medication.

Other researchers have written about the increase in older adults being prescribed multiple medications simultaneously. This trend is concerning because pharmacies likely miss half of these dangerous drug combinations.

Researchers have commented on the dangers of polypharmacy and inappropriate medication at length, including that older adults on multiple medications, are more likely to go to the hospital for adverse drug reactions. In addition, research has linked polypharmacy to cognitive decline (especially in elderly patients), neuroleptic malignant syndrome, and premature death.



Ishtiak-Ahmed, O. Köhler-Forsberg, E.L. Mortensen, et al., Concurrent use of polypharmacy and potentially inappropriate medications with antidepressants in older adults: A nationwide descriptive study in Denmark during 2015–2019, General Hospital Psychiatry (2023).