Researchers predicted who was depressed with 90 percent accuracy from this one sign.
Changes in heart rate can predict depression, new research finds.
Heart rate could provide an early warning sign of depression and indicate when it has resolved.
People who are depressed have a heart rate that is roughly 10 to 15 beats per minute higher than the non-depressed, the study demonstrated.
Depressed people also show less variation in their heart rate and do not experience the normal drop in heart rate during the night.
By wearing a heart rate monitor for 24 hours, researchers were able to predict who was depressed.
Dr Carmen Schiweck, the study’s first author, said:
“Put simply, our pilot study suggests that by just measuring your heart rate for 24 hours, we can tell with 90% accuracy if a person is currently depressed or not”.
The small pilot study included 32 people, half of whom were depressed.
Depressed people were given the rapid anti-depressant ketamine, an anaesthetic recently licensed for use in this way.
Dr Schiweck explained:
“Two innovative elements in this study were the continuous registration of heart rate for several days and nights, and the use of the new antidepressant ketamine, which can lift depression more or less instantly.
This allowed us to see that average resting heart rate may change quite suddenly to reflect the change in mood.”
Ketamine can take effect in just minutes, which helped researchers spot the link between heart rate and depression.
Dr Schiweck said:
“We knew that something was going on to link heart rate to psychiatric disorders, but we didn’t know what it was, and whether it would have any clinical relevance.
In the past researchers had shown that depressed patients had consistently higher heart rates and lower heart rate variability, but because of the time it takes to treat depression it had been difficult to follow up and relate any improvement to heart rate.
But when we realized that ketamine leads to a rapid improvement in mood, we knew that we might be able to use it to understand the link between depression and heart rate”.
The study measured people’s heart rate across 4 days and 3 nights.
Dr Schiweck explained the results:
“We found that those with depression had both a higher baseline heart rate, and a lower heart rate variation, as we expected.
On average we saw that depressed patients had a heart rate which was roughly 10 to 15 beats per minutes higher than in controls.
After treatment, we again measured the heart rates and found that both the rate and the heartrate fluctuation of the previously depressed patients had changed to be closer to those found in the controls.”
Among the depressed, heart rates did not drop during the night as is normal, said Dr Schiweck:
“Normally heart rates are higher during the day and lower during the night.
Interestingly, it seems that the drop in heart rate during the night is impaired in depression.
This seems to be a way of identifying patients who are at risk to develop depression or to relapse.”
The next stage for the researchers is to carry out a larger study, said Dr Schiweck:
“We need to remember that this is a small proof-of-concept study: 6 of our of our 16 initial patients responded to treatment with at least a 30% reduction on the Hamilton Rating scale for depression, so we need to repeat the work with a larger, anti-depressant free sample.
Our next step is to follow up depressed patients and patients who are in remission, to confirm that the changes we see can be used as an early warning system”.
The study was presented at the ECNP virtual congress (Schiweck et al., 2020).
