Amid the attention given to stroke survivors — who number 30.7 million people globally, according to the World Health Organization — the struggles faced by those looking after them can be overlooked. When an individual suffers a stroke, blood (and oxygen) supply to the brain is cut off, potentially causing severe and long-term physical disability. It is easy to see how this may adversely affect the person’s quality of life. However, the mental and emotional distress felt by his or her caregiver is often missed.

In a recent study, Dr Melvyn Zhang, Associate Consultant at the Institute of Mental Health, explored this matter as part of a team of four from the National University of Singapore (NUS). Dr Zhang, who is an Adjunct Research Scientist at the NUS Biomedical Institute for Global Health Research and Technology, along with two students from the NUS Yong Loo Lin School of Medicine and a fellow faculty member, sought to determine the global prevalence of anxiety and depressive symptoms among caregivers of stroke survivors.

“The Singapore Government’s ‘War on Diabetes’, declared in 2016, has put a lot of focus on this condition — and stroke is one complication that could arise from poorly-controlled diabetes,” says Dr Zhang. “It was timely for us to look into this issue and how it impacts caregivers.”

A Quantitative Approach

The aim of the study was to obtain the combined prevalence rates of depressive and anxiety symptoms among caregivers of stroke survivors globally. Dr Zhang and his team thus performed a meta-analysis, a procedure that combines the results of multiple studies and involves rigorous statistical analysis.

An extensive literature search was carried out to find relevant articles for the meta-analysis. The team combed through PubMed, Embase, PsycINFO, BIOSIS, ScienceDirect, and Cochrane CENTRAL databases from inception to June 2016. They then applied the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist — which contains items deemed essential for transparent reporting — to select articles for inclusion. Using this method, their initial search result of 1,259 records was whittled down to 12 studies comprising 1,756 caregivers.

Because there are more published studies dealing with depression rather than anxiety disorder, Dr Zhang’s team was only able to give a predicted prevalence for depressive symptoms. “We estimated a pooled prevalence of 17 percent for depressive symptoms in our study,” he says. “The existing literature gives a prevalence rate of 17 percent for depression in the general population, and we felt that depression should be as common among caregivers as in the general population.”

Bearing The Burden

The team’s research findings appeared in the February 2017 issue of the Journal of the American Medical Directors Association. To their surprise, they found a pooled prevalence rate of 40.2 percent for depressive symptoms among caregivers of stroke survivors — more than twice the predicted proportion. The pooled prevalence of anxiety symptoms was also quite worrying at 21.4 percent.

Upon closer look, Dr Zhang’s team found that depressive symptoms were most prevalent among female caregivers as well as caregivers of Caucasian ethnicity. “We know from literature that females are more vulnerable than males to depressive disorder,” he reasons. “Secondly, we speculated that the female gender may be more predisposed to caregiver stress because they are already called upon to serve multiple roles in the family; being a caregiver would count as an additional role.”

On why depression was more widespread in Caucasian caregivers than among other races, Dr Zhang hypothesises that it could be due to cultural differences. Asian societies tend to be collectivist in nature, while Western societies emphasise individualism. The lack of family or community support in the latter may exacerbate the caregiver burden.

Conversely, caregivers in a spousal or parent–child relationship with stroke victims had a low prevalence of depressive symptoms. “Seeing their loved ones gradually recover and regain a good quality of life may have resulted in better life satisfaction for this group of caregivers,” posits Dr Zhang. The caregiving experience may have also brought both sides closer together and deepened their bond with one another.

The meta-analysis has a couple of limitations given the available data. Dr Zhang and his team could not rule out the possibility that the caregivers may have had a previous history of psychiatric conditions before the onset of stroke in their charges. Moreover, only two of the 12 studies were based in Asia (namely, South Korea and Japan); the other studies involved Western populations.

Nonetheless, says Dr Zhang, “Our global study gives an overall outlook on the prevalence rates and is broadly applicable to the Asian cohort. We hope to conduct a study with the Singaporean cohort in the future.” The study will also help in guiding interventions to reduce depression and anxiety disorder among caregivers of stroke survivors.