Summary: Symptoms of depression often appeared before stroke and tended to worsen after the event, according to a long-term study.
Source: AAN
Depressive symptoms can begin years before a stroke and typically increase further following a stroke, researchers report in the July 13, 2022 online issue of Neurology.
In a large, long-term study, investigators tracked changes in depressive symptoms among older adults and found a clear pattern: people who later experienced a stroke showed rising depressive symptoms in the years leading up to the stroke, and these symptoms increased again after the stroke and remained elevated for many years.
Study lead author Maria Blöchl, PhD, from the University of Münster in Germany, notes that depression is already recognized as a common and serious issue after stroke—often called post-stroke depression—but the new findings highlight that depression can also be a pre-stroke phenomenon.
The study followed 10,797 adults with an average age of 65 who had no history of stroke at enrollment. Participants were observed for up to 12 years. During follow-up, 425 participants experienced a stroke. Each of these individuals was matched with up to ten comparison participants (4,249 people total) who did not have a stroke but were similar in age, sex, race or ethnicity, and other health characteristics.
Every two years, participants completed a brief survey assessing five common depressive symptoms experienced in the past week: feeling depressed, feeling lonely, feeling sad, perceiving that everything was an effort, and having restless sleep. The number of symptoms reported formed a simple score, with higher scores indicating more depressive symptoms.
Six years before the stroke, average symptom scores were similar in those who would later have a stroke and those who would not—about 1.6 points. Beginning about two years before the stroke, however, scores among those who later had a stroke began to rise, increasing on average by approximately 0.33 points. After the stroke, symptoms increased by another 0.23 points, bringing the average score to roughly 2.1 points. That higher level of symptoms persisted for up to ten years after the stroke. In contrast, scores among people who never had a stroke remained relatively stable throughout the study period.
When the researchers applied a commonly used threshold for probable clinical depression (a score of three points or higher), a slightly different pattern appeared. In the assessment just before a stroke, 29% of people who were about to have a stroke met the criteria for probable depression, compared with 24% of people who did not have a stroke. At the time of the stroke, 34% of those who had a stroke met the threshold for probable depression versus 24% of controls. About six years after the stroke, these percentages were similar to those observed at the time of stroke.
Blöchl emphasizes that the increase in depressive symptoms before a stroke is often subtle and may not always reach the threshold for clinical diagnosis. “Even small increases in mood-related and fatigue-related symptoms may signal an underlying process that precedes a stroke,” she said. In other words, depressive symptoms should not be viewed only as a consequence of stroke; they can also precede it.
The study does not establish a direct cause-and-effect relationship—whether rising depressive symptoms contribute to stroke risk or reflect early, undetected vascular changes is not yet clear. The authors call for additional research to clarify why depressive symptoms emerge prior to stroke and whether these changes might help identify people at higher risk.
A notable limitation of the analysis is the lack of detailed information about depression treatment. The researchers did not have complete data on whether participants received antidepressant medication or psychotherapy, so it is possible that some post-stroke improvements or stability in symptoms were influenced by treatment.
About this stroke and depression research news
Author: Natalie Conrad
Source: AAN
Contact: Natalie Conrad – AAN
Image: The image is in the public domain
Original Research: Findings published in Neurology