Antidepressants Impair Cognitive Function In The Elderly

June 22, 2000
Hershey, Pa. -- New research from Penn State's College of Medicine provides preliminary evidence that psychoactive drugs such as antidepressants have both immediate and cumulative negative effects on cognitive performance for people age 80 and over.

"These kinds of medications are often prescribed to actually improve cognitive function. This study showed the opposite result. These drugs are also already associated with a number of negative side effects such as adverse drug reactions, and falls in the elderly," explains Cheryl Dellasega, Ph.D., associate professor of general internal medicine and associate director of research. "The implications of this study include that physicians and family members need to be aware that these elderly patients may need help managing their medications."

Dellasega and her colleagues' presentation titled, "The Cognitive Consequences of Long-Term Psychoactive Medication Use for the Oldest Old," was presented recently at the American Geriatrics Society Meeting held in Nashville, Tenn. Co-authors include Denise Orwig, Ph.D., University of Maryland, Stig Berg, Ph.D., Halsohogskolan, Sweden, and James Walker, M.D., Penn State's College of Medicine. The work was recognized as among the top 10 percent of presentations at this meeting.

The three-year study was of 351 people from Sweden age 80 and over. The participants were drawn from the Origins of Variance in the Old-Old (OCTO)-Twin Study. (This is a longitudinal study on this group that tracks every twin in Sweden born in 1913). Each participant was interviewed for approximately three and a half hours using standard cognitive tests. Questions tested things such as short and long-term memory, reasoning, recognition of everyday items and simple calculations such as balancing a checkbook.

"The subjects were divided into three groups -- one that was not on any medications, another on psychoactive drugs at the start of the study, and a third group, which was not on medication at the start of the testing but later had to be put on the psychoactive medications," explains Dellasega. "All three groups tested at age 80 and then at age 82 showed a decline in cognitive function. The group that was not on any medication at the start and then later started taking medication showed the most severe drop in cognitive function."

Dellasega adds that about three-quarters of the entire group were on some kind of psychoactive medication. She reports that results clearly show that those on such medications do not function as well with their day-to-day activities.

The group of people aged 80 and over is one of the fastest growing segments of the population, and Dellasega believes they need more attention to their needs. "Many of these people take multiple medications daily. It can be difficult for them to keep those dosages correct," says Dellasega.

She adds that more research is needed to examine specific medications within classes to assess the long-tern effectiveness of psychoactive medications.