Persons with no history of stroke but who have symptoms of depression may experience a stroke later on, suggests a new study reported in the journal Neurology.¹ These symptoms aggravated after the stroke.

Researchers enrolled 10,797 participants, aged 65 years (average), from the English Longitudinal Study of Ageing (ELSA) with the aim to find out association of symptoms of depression before and after the incident stroke. Nearly 55% of them were women and none had a history of stroke at the time of their recruitment. A total of 4,249 age-, gender-, education-, ethnicity-matched persons and who did not have a stroke were selected as controls. The two groups were also matched for vascular risk factors. Participants were also surveyed about the symptoms of depression in the past week, every two years for the duration of the study.

Over a follow-up period of 12 years, 425 of the 10,797 participants suffered an incident stroke. Analysis of data also revealed an increase in the symptoms of depression in these individuals compared to the control group. These symptoms increased further among those who survived the stroke. The depressive symptom scores at 6 years prior to the occurrence of stroke were comparable (1.6 points) between those who developed a stroke later on and those who did not. However, a rising trend in the score (by an average of 0.33 points) was noted two years before the stroke among those who had a stroke. Post-stroke, the score increased by 0.23 points. The high scores persisted for a decade after the stroke. No such variation in the symptom score was observed among those who did not have a stroke. The difference in pre- and post-stroke depression score was particularly strong for fatigue- and mood-related symptoms.

Twenty-nine percent of patients who were to suffer a stroke could be labelled as probable depression versus 24% of the stroke-free controls. But when the stroke occurred, 34% of the people who had a stroke met the criteria for having probable depression, compared to 24% of those who did not have a stroke. These observations persisted for six years after the stroke.

This study has demonstrated an association between occurrence of first stroke and symptoms of depression prior to the stroke, which increased closed to the acute event. While post-stroke depression is common in persons who have had a stroke, in this study the depressive symptoms not only increased after the stroke, but were already present before the stroke had occurred. While it does not establish a cause-and-effect link, it suggests the necessity of closely monitoring individuals with depression, especially those who show even a mild increase in the intensity of their symptoms, for an impending stroke.

Reference

1. Maria Blöchl, et al. Long-term changes in depressive symptoms before and after stroke. Neurology. 2022 Jul 13;10.1212/WNL.0000000000200756. doi: 10.1212/WNL.0000000000200756.
2. AAN press release, July 13, 2022.