Cardiovascular disease is the number one killer for Australian women. And their increased risk of experiencing depression and anxiety is a contributing factor.
The Heart and Mind research group at Deakin University’s Institute for Mental and Physical Health and Clinical Translation (IMPACT) is dedicated to understanding the link between cardiovascular and mental health.
In a recent study, they found that women are more likely to experience poor health outcomes after a cardiac event. And mental illness can further exacerbate the problem.
Mental and cardiac health go hand-in-hand
The ADVENT study – conducted by the Heart and Mind research group in conjunction with University of Melbourne and Monash Heart – followed 416 patients who experienced a heart event at a large Victorian hospital.
The group found that male patients who were treated with a medical stent upon admission were only half as likely to be re-hospitalised within two years, in comparison to female patients who did not receive the stent.
“No other group benefited to this extent,” says Associate Professor Adrienne O’Neil, Director of the Heart and Mind research group.
“Women are more likely to have a history of common mental illness before – and are more susceptible to it after – a cardiac event.”
A/Prof O’Neil says that differences in the way female patients are diagnosed, treated, and monitored over the course of their time in hospital is known to contribute to poorer survival outcomes.
For instance, women are less likely to receive relevant medications or referrals for cardiac rehabilitation once they’ve been discharged.
The consequences are visible further down the line: as much as one year after their surgeries, female patients tend to have a higher heart rate, with an equally poor rate variability.
This suggests that they come out the other side of major cardiac events with poorer autonomic function, a key mechanism that links the heart and the mind.
Factors like depression and anxiety can only further exacerbate the problem.
Fortunately, there are a number of interventions that can improve the health of both the heart and the mind, such as eating a healthy diet or attending exercise-based, cardiac rehabilitation.
But A/Prof O’Neil says it’s imperative that we address the disparities in care that female patients face during major cardiac events.
“This is not just about women being older at the time of their first cardiovascular event – the latest Australian data show that young women 35-54 years are actually having strokes and other cardiovascular events more frequently than ever before.
“Simply providing them evidence-based cardiovascular care is a critical first step to improve women’s sub-optimal outcomes, especially when they are experiencing depression and anxiety.”
The vagus connection
We know that depression and anxiety can hinder recovery from a cardiac event. But can they cause one?
On the surface, it might seem that mental illness merely contributes to behaviours that can lead to poor health, such as smoking, unhealthy diets, sedentary behaviour and overconsuming alcohol.
And each of these things can negatively impact our health. But A/Prof O’Neil says there’s more to it than meets the eye.
“From a biological point of view, heart and mental health conditions share some physiological pathways.”
For instance, the heart and the mind are linked by the vagus nerve, which is responsible for our fight or flight response.
It counters our physiological reaction – be that a racing heart or sweaty palms – to a threat or stress. This helps us stay balanced in distressing circumstances.
It’s been proposed that people suffering from depression and anxiety struggle to create that counter response. Over time, this can put pressure on the heart and other organs.
“Depression and heart disease also share inflammatory pathophysiology,” A/Prof O’Neil says.
“This means that both are characterised by the body being in a constant state of low grade inflammation, which perpetually incites an immune response.
“This state can bring about a cardiac event in the long term.
“Fortunately, the anti-inflammatory effects of the Mediterranean diet, physical activity, and reducing smoking and alcohol consumption are thought to provide some protection over this effect.”
The female paradox
Women run the highest risk of experiencing depression and anxiety-induced cardiac events.
In fact, they’re at risk for most of their lives: A/Prof O’Neil says that girls and women have higher rates of mental illness than men, until they reach 75 years of age.
Although women tend to live longer than their male counterparts, they do so in poorer health, with a greater level of disability, and at a profound socioeconomic disadvantage. This is known as the female paradox.
A/Prof O’Neil says that this disadvantage is even more pronounced for First Nations women and other women of colour.
“It’s important to understand that mental and heart health occur on a social gradient,” she says. “The environment in which we live, work, play and age shapes our health.
“First nations women, for example, are more likely to live in poverty, and often with reduced access to food security.
“They also face structural racism and inter-generational trauma, which have a physiological effect on their cardiovascular system.
“This confers even greater risk.”
Not only is cardiovascular disease the number one killer of Australian women, but First Nations women are twice as likely to die from it than those who are not.
So, how does this information change the way we approach mental and cardiac health?
Given their correlation, A/Prof O’Neil suggests that mental wellbeing check-ups could be offered alongside heart health check-ups, and vice versa.
“But with the health system set up in a siloed fashion, it’s often difficult for health professionals to refer their patients to get them the help they need.
“What some people don’t realise is that many of the same prevention and management approaches that are so useful in cardiac disease are applicable in mental health too, such as lifestyle-based programs that are adjunctive to medications.
“It stands to reason that lifestyle-based interventions, especially provided to patients early in their mental health journey, could reduce depression and anxiety, and so delay or prevent their progression into clinical disorders. This is something we are exploring at Heart and Mind research.
“It would also have the dual benefit of mitigating the risk of chronic disease – the health and economic benefits are a no-brainer.”
Associate Professor Adrienne O’Neil is Director of Heart and Mind research at IMPACT and is supported by a Future Leader Fellowship. She is also Deputy Director of the Food and Mood Centre.