Low blood pressure links to depression

SCIENTISTS have discovered that having low blood pressure could increase the risk of depression by nearly a third.

A study shows patients with lower than normal blood pressure may be 30% more likely to become depressed than those with healthy or even high readings.

The surprising findings, from researchers at Trinity College, Dublin, suggest some cases of depression may be owing to reduced blood flow to the brain caused by low blood pressure (or hypotension).

If further studies confirm the link, researchers believe it might be possible to treat depressed patients who also have hypotension by increasing their blood pressure.

The rise in depression diagnoses has led to a massive uptake of drugs such as Prozac, known as selective serotonin reuptake inhibitors (SSRIs). They are thought to improve mood by raising levels of the “feel-good” chemical serotonin in the brain.

But the discovery that low blood pressure could be linked to depression means patients might in future be able to avoid SSRIs and be given drugs or other strategies for low blood pressure.

These might include drinking more water, eating more salt (because it increases blood pressure by retaining fluid in the body) or taking medicines such as the steroid fludrocortisone, which also help the body retain fluid.

Blood pressure is measured by testing systolic pressure (the top reading, which measures the force generated by blood when the heart beats) and diastolic pressure (the force between beats).

According to the charity Blood Pressure UK, a healthy reading is around 120/80. Those scoring 140/90 or more are at increased risk of heart attacks and strokes.

But the latest study suggests low average readings may be bad news for mental health.

The Irish researchers tested more than 4 500 men and women aged over 50 for two years. Each had their blood pressure checked at the start of the study and their mental health assessed. Those with existing signs of depression or who were taking antidepressants were excluded so as not to skew the findings.

The rest were tested after two years and the results, published in the journal Age and Ageing, showed around 200 went on to develop depression. Those with systolic blood pressure readings consistently below 130 at the beginning were 30% more likely to have mental health problems. The researchers reported: “Hypotension may represent a modifiable risk factor for depression.”

The findings back up a huge study carried out in Scandinavia which had similar results. The Norwegian team said low blood pressure may upset the balance of hormones needed to avoid anxiety or depression.

Sandosh Padmanabhan, a retired professor of cardiovascular genomics and therapeutics at the University of Glasgow told Good Health: “The latest study shows that people who have low blood pressure tend to score towards depression on a simple questionnaire.

“It does not show that low blood pressure causes depression.”

Stephen Buckley, head of information at the mental health charity, Mind, said: “These findings highlight an area worth exploring.” – Daily Mail