How Mental illness damages the heart

A new study published in BioMedical Engineering draws a link between mental illness and widely fluctuating blood pressure, which can lead to cardiovascular disease and organ damage.

They found that for people who are mentally ill, their heart rate does not adapt to external stressors as it should.

“Contrary to what many people think, a healthy heart is not one that beats like a metronome. Instead, it should adjust to withstand environmental and psychological challenges. A constantly changing heart rate is actually a sign of good health”, Dr Lim says.

12 studies on people with anxiety, depression and panic disorders and found that, regardless of age, mental illness is significantly associated with greater blood pressure variations during the day.

Reduced heart rate variation (HRV) is common in people with mental illness and indicates that the body's stress response is poor, worsening the negative effects of chronic stress.

Unlike a person's heart rate -- how many times a heart beats in a minute -- which is usually consistent, HRV is more complex and is the time between two heartbeats, which should change according to external stressors.

Low HRV occurs when a person's body is in fight-or-flight mode, easily stressed and common in people with chronic diseases, including cardiovascular and mental health problems.

While large blood pressure variations (BPV) during the day are not ideal, at night the systolic pressure should dip by between 10-20 per cent to allow the heart to rest. The researchers found that in people with mental health issues, their blood pressure does not drop sufficiently at night.

The reduced dipping -- under 10 per cent -- can be caused by many factors, including autonomic dysfunction, poor quality of sleep and disrupted circadian rhythms that regulate the sleep-wake cycle.

Takeout from this study is that we need to pay more attention to the physical impacts of mental illness.