Depression after stroke linked to higher mortality and disability over a decade

People who experience depression following a stroke may face a higher risk of poor health and even death for up to a decade afterward, new research finds.

A study by researchers from King's College London, funded by the National Institute for Health and Care Research (NIHR), has found that post-stroke depression (PSD) can have serious long-term effects on stroke survivors, lasting up to 10 years after the initial stroke. The findings emphasise a need for long-term mental health support in stroke rehabilitation.

Researchers tracked over 2,500 stroke survivors using data from the South London Stroke Register, a population-based register recruiting stroke patients living within Lambeth and Southwark. They examined the participants' health for up to 10 years to understand the long-term consequences of depression for stroke survivors.

Published in The Lancet Regional Health – Europe, the study found that 36% of participants showed signs of depression three months after their stroke and survivors with PSD were nearly three times more likely to develop long-term physical disability compared to those without depression. They also faced a 30% higher risk of death in the decade following their stroke and were more likely to struggle with daily tasks and have a reduced quality of life.

Continued depression at one or five years after the stroke was associated with higher risks of death, more physical disability and lower quality of life. In contrast, survivors who recovered from PSD within the first year had a similar risk of death to those who never experienced depression. Recovery during this period was also linked to a lower risk of another stroke, better functional outcomes, and improved quality of life. Although the timing of depression onset didn't appear to affect long-term health risks, recovering from depression was associated with better physical and mental well-being.

Lu Liu, a PhD student at King's College London and lead researcher on the study, said: "Post-stroke depression is linked to higher mortality and worse functional outcomes, but most previous studies have only followed patients for less than a year. Our study examined the long-term impact of depression after a stroke. These findings show how important it is to recognise and treat depression as part of stroke recovery."

Depression was identified using a questionnaire, and participants' ability to perform daily activities, their physical independence, and their overall quality of life, both physical and mental, were also assessed.

The South London Stroke Register has been collecting data since 1995, but follow-up typically ends after 10 years, as tracking patients beyond this point becomes increasingly difficult due to cognitive decline or communication challenges, which can affect the reliability of the data.

People often take depression seriously in the first few months after a stroke, but years later it can be overlooked. Just because the stroke happened five or six years ago doesn't mean the depression is any less serious. Our findings show that post-stroke depression remains a major risk factor long after the initial stroke and needs ongoing attention from clinicians."

Professor Yanzhong Wang, Professor of Statistics in Population Health at King's College London and co-senior author of the study

Dr. Matthew O'Connell, Senior Lecturer in Health Services Research and Population Health Sciences at King's College London and co-senior author of the study, said: "The South London Stroke Register is unique in following stroke survivors for so many years after their stroke. Encouragingly, our data show those recovering from depression experience better outcomes in the longer term, suggesting effectively treating these symptoms could have broader ranging health benefits."

Currently, post-stroke care primarily focuses on physical recovery, with depression often only screened in the early stages. The researchers hope their findings will encourage the inclusion of long-term mental health support in stroke rehabilitation programmes. While more research is needed to develop effective treatments for PSD, these results underline the need for continued care that addresses both physical and mental health.

The South London Stroke register is funded by an NIHR programme grant, led by Dr Iain Marshall at King's College London. The study was supported by the NIHR Applied Research Collaboration (ARC) South London.